# SGSN Service Configuration Procedures

This chapter provides configuration instructions to enable the SGSN to function in GPRS (2.5G), UMTS (3G), or LTE (4G) networks. The System Administration Guide provides interface and system-level configuration details and the Command Line Interface Reference provides additional command information.

IMPORTANT:

Please note that LTE (4G) support is only available in releases 14.0 an higher.

High level step-by-step service configuration procedures are provided for the following:

- 2.5G SGSN Service Configuration
- 3G SGSN Service Configuration
- Dual Access SGSN Service Configuration
- Configuring the S4-SGSN

IMPORTANT:

At least one packet processing card must be activated prior to configuring the first service. Procedures for configuring the packet processing card can be found in the System Administration Guide.

Detailed procedures are provided for the following:

- Configuring an SS7 Routing Domain
  - Configuring an SS7 Routing Domain to Support Broadband SS7 Signaling
  - Configuring an SS7 Routing Domain to Support IP Signaling for SIGTRAN
- Configuring GTT
- Configuring an SCCP Network
- Configuring a MAP Service
- Configuring an IuPS Service (3G only)
- Configuring an SGTP Service
- Configuring a Gs Service
- Configuring a GPRS Service (2.5G only)
- Configuring an SGSN Service (3G only)
- Configuring a Network Service Entity
  - Configure a Network Service Entity for IP
  - Configure a Network Service Entity for Frame Relay
- Configuring DNS Client
- Configuring GTPP Accounting Support
- Configuring and Associating the EGTP Service (S4 Only)
- Configuring DNS for APN Resolution (S4 Only)
- Configuring the S6d Diameter Interface (S4 Only)
  - Configuring the Diameter Endpoint for the S6d Interface
  - Configuring the HSS Peer Service and Interface Association for the S6d Interface
  - Associating the HSS Peer Service with the SGSN and GPRS Services for the S6d Interface
  - Configuring Operator Policy-Based S6d Interface Selection (Optional)
  - Configuring the Subscription Interface Preference for the S6d Interface (Optional)
- Configuring the S13’ Interface (S4 Only)
  - Configure a Diameter Endpoint for the S13’ Interface
  - Configuring the HSS Peer Service and Interface Association for the S13’ Interface
  - Associate the HSS Peer Service with the SGSN Service for the S13’ Interface
  - Configuring Operator Policy-Based S13’ Interface Selection
- Configuring QoS Mapping for EPC-Capable UEs using the S4 Interface (S4 Only)
- Configuring the Peer SGSN Interface Type (S4 Only, Optional)
- Configuring Operator Policy-Based Gn Interface Selection (S4 Only, Optional)
- Configuring a Custom MME Group ID (S4 Only, Optional)
- Configuring the Selection of an SGW for RAI (S4 Only, Optional)
- Configuring a Local PGW Address (S4 Only, Optional)
- Configuring the Peer MME Address (S4 Only, Optional)
- Configuring the ISR Feature (S4 Only, Optional)
- Creating and Configuring ATM Interfaces and Ports (3G only)
- Creating and Configuring Frame Relay Ports (2.5G only)
- Configuring APS/MSP Redundancy

## 2.5G SGSN Service Configuration

The following configuration steps must be completed to allow the system to operate in a 2.5G GPRS network.

The service handling the GPRS or 2.5G functions in the SGSN is called the “gprs-service”.

1. Create all the contexts you will use in your configuration. Refer to the “System Element Configuration Procedures” chapter in the System Administration Guide.
2. Create and configure the Frame Relay interface(s) and Ethernet interface(s). Refer to the “System Element Configuration Procedures” chapter in the System Administration Guide.
3. Configure SS7 routing domains. Use the procedure in Configuring an SS7 Routing Domain. The concept of an SS7 routing domain is not a standard SS7 concept. It is a concept specific to this platform which groups a set of SS7 feature configuration together to facilitate the management of the SS7 connectivity resources for an SGSN service.
4. Configure GTT. The GTT configuration is used to set rules for GTT and define the GTT databases. Follow the procedure in Configuring GTT.
5. Configure SCCP-Networks. The purpose of an SCCP network is to isolate the higher protocol layers above SCCP and the application itself from SS7 connectivity issues, as well as, to provide a place for global SCCP configuration specific to SGSN services. Use the procedure in Configuring an SCCP Network.
6. Configure MAP services. The MAP service configuration is used by the SGSN service to communicate with many of the nodes on the narrow band-SS7 network part of the network such as HLR, EIR, GSM-SCF, GMLC and SMS-GMSC/SMS-IWMSC. The purpose of having an isolated map configuration is to enable different application services to use the map service to communicate with other map entities in the network. Use the procedure in Configuring a MAP Service.
7. Configure SGTP. The SGTP service configures the parameters used for GTP Tunneling. At the minimum, interfaces for GTP-C and GTP-U must be configured. Use the procedure in Configuring an SGTP Service.
8. Configure the SGSN service. All the parameters specific to the operation of an SGSN are configured in the SGSN service configuration mode. SGSN services use other configurations like MAP and IuPS to communicate with other elements in the network. The system can support multiple SGSN services. Use the procedure in Configuring an SGSN Service (3G only).
9. Configure the GPRS service. All of the parameters needed for the system to perform as a an SGSN in a GPRS network are configured in the GPRS service. The GPRS service uses other configurations such as SGTP and MAP to communicate with other network entities and setup communications between the BSS and the GGSN. Use the procedure in Configuring a GPRS Service (2.5G only).
10. Configure the Network Service Entity Instance. This identifies the NSEI to use and associates it with a Network Service Virtual Connection Identifier. Use the procedure in Configuring a Network Service Entity.
11. Configure DNS. This configuration enables domain name resolution and specifies the DNSs to use for lookup. Use the procedure in Configuring DNS Client.
12. Configure GTPP Accounting. This configures GTPP-based accounting for subscriber PDP contexts. Use the procedure in Configuring GTPP Accounting Support.
13. Configure Frame Relay DLCI paths and bind them to NSEI links as needed. Refer to Creating and Configuring Frame Relay Interfaces and Ports in the System Administration Guide.
14. Save your configuration to flash memory, an external memory device, and/or a network location using the Exec mode command save configuration. For additional information on how to verify and save configuration files, refer to the System Administration Guide and the Command Line Interface Reference.

## 3G SGSN Service Configuration

The following configuration steps must be completed to allow the system to operate in a 3G network.

1. Create the contexts needed. Refer to the System Element Configuration Procedures chapter in the System Administration Guide.
2. Create any interfaces needed in the appropriate context. Refer to the System Element Configuration Procedures chapter in the System Administration Guide for IP (broadcast Ethernet) interfaces and for ATM interfaces.
3. Configure SS7 routing domains. The SS7 routing domain is proprietary concept to provide a combined configuration for the SS7 links, linksets, and related parameters. SS7 routing domain configurations are common to both SIGTRAN and MTP3-B networks. Use the procedure in Configuring an SS7 Routing Domain.
4. Configure global title translations (GTT). The GTT configuration is used to set rules for GTT and to define the GTT databases. Follow the procedure in Configuring GTT.
5. Configure SCCP networks. The SCCP network (layer) provides services to protocol layers higher in the SS7 protocol stack, for example RANAP and TCAP. The SCCP layer is also responsible for GTT. As well, all the SS7 routing domains (created in step 3) will be associated with an SCCP network. Use the procedure in Configuring an SCCP Network.
6. Configure MAP services. The MAP service configuration is used by the SGSN service to communicate with many of the nodes in the SS7 network, such as the HLR, EIR, GSM-SCF, GMLC and SMS-GMSC/SMS-IWMSC. Having an isolated MAP configuration enables different application services to use the MAP service to communicate with other MAP entities in the network. Use the procedure in Configuring a MAP Service.
7. Configure IuPS services. A set of parameters define the communication path between the SGSN service and radio network controllers (RNCs) in a UMTS IuPS service. Use the procedure in Configuring an IuPS Service (3G only).
8. Configure SGTP services. The SGTP service configures the parameters used for GTP Tunneling. At a minimum, interfaces for GTP-C and GTP-U must be configured. Use the procedure in Configuring an SGTP Service.
9. Configure the SGSN service. All the parameters specific to the operation of an SGSN are configured in the SGSN service configuration mode. SGSN services use other configurations like MAP and IuPS to communicate with other elements in the network. The system can support multiple SGSN services. Use the procedure in Configuring an SGSN Service (3G only).
10. Configure DNS clients. This configuration enables domain name resolution and specifies the DNSs to use for lookup. Use the procedure in Configuring DNS Client.
11. Optional: Configure operator policies. Operator policies are not required for SGSN operation, however, they provide the operator with a powerful method for determining call handling. SGSN operator policies specify rules governing the services, facilities and privileges available to a single subscriber or groups of subscribers. Use the procedure in Configuring SGSN Operator Policies.
12. Configure GTPP Accounting. This configures GTPP-based accounting for subscriber PDP contexts. Use the procedure in Configuring GTPP Accounting Support.
13. Configure ATM PVCs and bind them to interfaces or SS7 links as needed. Refer to Creating and Configuring ATM Interfaces and Ports in the System Administration Guide.
14. Save your configuration to flash memory, an external memory device, and/or a network location using the Exec mode command save configuration. For additional information on how to verify and save configuration files, refer to the System Administration Guide and the Command Line Interface Reference.

## Dual Access SGSN Service Configuration

The following configuration steps must be completed to allow the SGSN to operate in both GPRS (2.5G) and UMTS (3G) networks. This type of co-location is referred to as dual access.

To configure dual access requires a combination of steps from both the 2.5G and 3G configuration procedures:

1. Create the contexts needed. Refer to the System Element Configuration Procedures chapter in the System Administration Guide.
2. Create any interfaces needed in the appropriate context refer to the System Element Configuration Procedures chapter in the System Administration Guide.
   1. For IP (broadcast Ethernet) interfaces, refer to Creating and Configuring Ethernet Interfaces and Ports in the System Administration Guide.
   2. For ATM interfaces (3G) refer to Creating and Configuring ATM Interfaces and Ports in the System Administration Guide.
   3. For Frame Relay interfaces (2.5G) refer to Creating and Configuring Frame Relay Interfaces and Ports in the System Administration Guide.
3. Configure SS7 routing domains. The SS7 routing domain is a non-standard, proprietary SS7 concept specific to this platform. SS7 routing domains provide a combined configuration for the SS7 links, linksets, and related parameters for SS7 connectivity resources for an SGSN service. SS7 routing domain configurations are common to both SIGTRAN and MTP3-B networks. Use the procedure in Configuring an SS7 Routing Domain.
4. Configure global title translations (GTT). The GTT configuration is used to set rules for GTT and to define the GTT databases. Follow the procedure in Configuring GTT.
5. Configure SCCP networks. The SCCP network (layer) provides services to protocol layers higher in the SS7 protocol stack, for example RANAP and TCAP. The SCCP layer is also responsible for GTT (step 4) and every SS7 routing domain (step 3) will be associated with an SCCP network. Use the procedure in Configuring an SCCP Network.
6. Configure MAP services. The MAP service configuration is used by the SGSN service to communicate with many of the nodes in the SS7 network, such as the HLR, EIR, GSM-SCF, GMLC and SMS-GMSC/SMS-IWMSC. Having an isolated MAP configuration enables different application services to use the MAP service to communicate with other MAP entities in the network. Use the procedure in Configuring a MAP Service.
7. Configure IuPS services. A set of parameters define the communication path between the SGSN service and radio network controllers (RNCs) in a UMTS IuPS service. Use the procedure in Configuring an IuPS Service (3G only).
8. Configure SGTP services. The SGTP service configures the parameters used for GTP Tunneling. At a minimum, interfaces for GTP-C and GTP-U must be configured. Use the procedure in Configuring an SGTP Service.
9. Configure the GPRS service. All of the parameters needed for the system to perform as a an SGSN in a GPRS network are configured in the GPRS service. The GPRS service uses other configurations such as SGTP and MAP to communicate with other network entities and setup communications between the BSS and the GGSN. Use the procedure in Configuring a GPRS Service (2.5G only).
10. Configure the Network Service Entity Instance. This identifies the NSEI to use and associates it with a Network Service Virtual Connection Identifier. Use the procedure in Configuring a Network Service Entity.
11. Configure DNS. This configuration enables domain name resolution and specifies the DNSs to use for lookup. Use the procedure in Configuring DNS Client.
12. Configure GTPP Accounting. This configures GTPP-based accounting for subscriber PDP contexts. Use the procedure in Configuring GTPP Accounting Support.
13. Configure ATM PVCs and bind them to interfaces or SS7 links as needed. Refer to Creating and Configuring ATM Interfaces and Ports in the System Administration Guide.
14. Configure Frame Relay DLCI paths and bind them to NSEI links as needed. Refer to Creating and Configuring Frame Relay Interfaces and Ports in the System Administration Guide.
15. Save your configuration to flash memory, an external memory device, and/or a network location using the Exec mode command save configuration. For additional information on how to verify and save configuration files, refer to the System Administration Guide and the Command Line Interface Reference.

## Configuring the S4-SGSN

The following configuration steps comprise the required and optional tasks for configuring the S4-SGSN to provide an interface between GPRS (2.5G) / UMTS (3G) networks and EPC (4G) networks via the EPC S4 interface. This is referred to as an S4-SGSN.

CAUTION:

The S4-SGSN cannot operate until after 2G, 3G or dual access SGSN service is configured. Do not begin S4-SGSN configuration until one of those services is configured and operational. Refer to the 2.5G SGSN Service Configuration, 3G SGSN Service Configuration, or Dual Access SGSN Service Configuration sections in this chapter for details on configuring those services.

Before you begin the configuration procedure, note the following:

- Configuration steps 1 through 7 are required for the S4-SGSN to operate properly.
- Configuration steps 8 through 13 are optional. They can be used to bypass DNS resolution for various network elements, configure GUTI-to-RAI mapping, and to enable the license-enabled Idle Mode Signaling Reduction feature.

1. Configure, 2G, 3G or Dual Access SGSN service support. Refer to the 2.5G SGSN Service Configuration, 3G SGSN Service Configuration, or Dual Access SGSN Service Configuration sections in this chapter for the configuration
2. Configure and associate the EGTP service. The EGTP service is required to support communication between the SGSN and the EPC SGW over the S4 interface using the GTPv2 protocol. Refer to the Configuring and Associating the EGTP Service (S4 Only) procedure.
3. Configure DNS for APN resolution. Configurables must be set to enable the default DNS client on the SGSN to resolve EPC PGW and SGW addresses. Refer to the Configuring the DNS Client Context for APN and SGW Resolution procedure.
4. Configure the S6d Diameter Interface. The S6d interface is used by the SGSN to communicate with the HSS. The HSS is a master user database that contains all subscription related information, Refer to the Configuring the S6d Diameter Interface (S4 Only) procedure.
5. Configure the S13’ (S13 prime) interface. This interface is used to perform Mobile Equipment (ME) identity check procedure between the SGSN and Equipment Identity Registry. Refer to the Configuring the S13’ Interface (S4 Only) procedure.
6. Configure QoS mapping between EPC elements and the SGSN. The S4-SGSN communicates QoS parameters towards the SGW/ PGW and EPC UEs in different formats. Operators must configure the SGSN quality of service (QoS) parameters as a call-control-profile that will ensure proper QoS mapping between the S4-SGSN, SGW/PGW and UEs. Refer to the Configuring QoS Mapping for EPC-Capable UEs Using the S4 Interface (S4 Only) procedure.
7. Optional. Configure the interface type used by the S4-SGSN to communicate with the peer SGSN. Refer to the Configuring the Peer SGSN Interface Type (S4 Only, Optional) procedure.
8. Optional. Configure Gn interface selection for EPC-capable UEs based on an operator policy. By default, the SGSN selects the S4 interface for EPC-capable UEs when the EGTP service is configured. However, operators have the option to forcefully select the Gn interface for these UEs. Refer to the Configuring Gn Interface Selection Based on an Operator Policy (S4 Only, Optional) procedure.
9. Optional. Configure a custom MME group ID. For operators who are using LAC ranges between 32768 and 65535 in UMTS/GPRS deployments, rather than for MMEs in LTE deployments, the SGSN provides a workaround to ensure backward compatibility. Refer to the Configuring a Custom MME Group ID (S4 Only, Optional) procedure.
10. Optional. Configure the S-GW for a RAI. If operators wish to bypass DNS resolution for obtaining the EPC S-GW address, the S4-SGSN can select a locally configured S-GW by performing a local look-up for the current RAI. Refer to the Configuring the Selection of an SGW for RAI (S4 Only, Optional) procedure.
11. Optional. Configure a Local PGW Address. For operators who wish to bypass DNS resolving an EPC P-GW address, the SGSN can be configured with a local P-GW address as part of an APN profile. Refer to the Configuring a Local PGW Address (S4 Only, Optional) procedure.
12. Optional. Configure the peer MME address. If operators wish to bypass DNS to resolve the peer MME address, the SGSN supports the local configuration of a peer MME address for a given MME group (LAC) and MME code (RAC). Refer to Configuring the Peer MME Address (S4 Only, Optional) procedure.
13. Optional. Configure the Idle Mode Signaling Reduction (ISR) feature. The ISR is a license-enabled feature allows the UE to roam between LTE and 3G networks while reducing the frequency of TAU and RAU procedures due to the UE selecting E-UTRAN or UTRAN networks. Refer to the Configuring the ISR Feature (S4 Only, Optional) procedure.
14. Optional. Enable the setup of indirect data forwarding tunnels (IDFT) between the eNodeB and the RNC via the SGW during connected mode handovers. This allows for connected mode handovers between the UTRAN and E-UTRAN networks across the S3 (S4-SGSN-to-MME) interface. Refer to Configuring IDFT for Connected Mode Handover (S4 Only, Optional).

Configuring an SS7 Routing Domain

The SGSN supports both SS7- and IP-based routing. IP-based routing is provided through the use of contexts. SS7 routing is facilitated through the configuration and use of SS7 routing domains. SS7 routing domains group SS7-related configuration parameters. Depending on the SS7 signaling method, an SS7 routing domain may be configured with one of the following:

- Linksets: Used for broadband SS7 signaling, linksets are comprised of link ids that specify point codes for SCCP endpoints. It is important to note that SCCP endpoints are further defined through the configuration of SCCP Networks (refer to Configuring an SCCP Network) which are associated with the SS7 routing domain in which the linkset is configured.
- Application Server Processes (ASPs) / Peer Server Processes (PSPs): Used for IP (SIGTRAN), M3UA ASPs and PSPs dictate the IP address and port information used to facilitate communication between network endpoints. ASPs refer to the local endpoints.

### Configuring an SS7 Routing Domain to Support Broadband SS7 Signaling

1. In global configuration mode, create a new SS7 routing domain, give it a unique ID and specify the network variant that SS7 communications through this routing domain use.
2. In SS7 routing domain configuration mode, configure the MTP-3 sub-service field (SSF).
3. Create an SS7 linkset with a unique ID.
4. In linkset configuration mode, specify the self point code - this is the point code of the SGSN.
5. Specify the adjacent point code to communicate with another SS7 node, e.g., an RNC.
6. Configure individual links, identified with link IDs.
7. In link configuration mode, specify the MTP3 link priority.
8. Specify the Signaling Link Code (SLC) for this link. This must be unique to this link within the current linkset. Note that SLCs must match, one-to-one, with those defined for the peer nodes.
9. Configure this link to use either passive or active arbitration.
10. In SS7 routing domain configuration mode, configure SS7 routes by specifying destination point codes and associated linkset IDs.

Example Configuration

    configure

      ss7-routing-domain <id> variant <variant>

          ssf <subsvc>

          linkset id <id>

             self-point-code  <#.#.#>

             adjacent-point-code <#.#.#>

             link id <id>

                priority <pri>

                signaling-link-code <code>

                arbitration <arbitration>

                exit

             exit

       route destination-point-code <dpc> linkset-id <id>

       end

### Configuring an SS7 Routing Domain to Support IP Signaling for SIGTRAN

To configure IP, the SS7 routing domain must be configured in a specific way as described below:

1. In Global configuration mode, create a new SS7 routing domain, give it a unique ID and specify the network variant that SS7 communications through this routing domain use.
2. In SS7 Routing Domain configuration mode, configure the MTP-3 subservice field.
3. Create an ASP (Application Service Part) instance for M3UA ASP configuration and give it a unique ID.
4. Specify the local SCTP (Stream Control Transmission Protocol) end-point IP address and the name of the context where the IP interface associated with the address is configured.

   IMPORTANT:

   At least one address needs to be configured before the end-point can be activated.
5. Specify the end-point SCTP port address to be used. Default port address is 2905.
6. Bind the end-point to the application server process (ASP) instance to activate it.
7. In SS7 routing domain configuration mode, create a peer server configuration with a unique ID.
8. Name the peer server configuration. Usually this is the name of the SS7 network entity that this instance is configured to communicate with, for example an HLR, an STP, or an RNC.
9. Specify the M3UA routing context ID.
10. Create a PSP instance and give it a unique ID.
11. In PSP configuration mode, specify the PSP mode in which this PSP instance should operate.
12. Specify the communication mode this PSP instance should use as client or server.
13. Configure the exchange mode this PSP instance should use. Generally this is not configured for IPSP-SG configuration, e.g., SGSN and STP.
14. Configure the IP address of the peer node SCTP end-point for this PSP instance. At least one address needs to be configured before the end-point can be activated. Up to two addresses can be configured.
15. Specify the ID of the ASP instance with which to associate this PSP instance.
16. Configure SS7 routes, in SS7 routing domain configuration mode, by specifying destination point codes and peer server IDs. Routes are configured if the destination point code (DPC) is at least a hop away from the SGSN or when the DPC is not the same as the peer server. For example, the route is configured between the SGSN and the HLR which communicates through STPs or signaling gateways. In this case, the signaling gateways are configured as the peer server on the SGSN.

Example Configuration

    configure

       ss7-routing-domain <id> variant <variant>

          ssf <subsvc>

          asp instance <instance_id>

             end-point address <address> context <ctxt_name>

             end-point bind

             exit

          peer-server id <id>

             name <name>

             routing-context <ctxt_id>

             psp instance <id>

                psp-mode <mode>

                exchange-mode <mode>

                end-point address <address>

                associate asp instance <id>

                exit

             exit

          route destination-point-code <dpc> peer-server-id <id>

       end

## Configuring GTT

Global Title Translation (GTT) configuration consists of defining GTT associations, defining GTT address maps, and referring to these in an SCCP network configuration. The GTT Associations define GTT rules applicable to a specific GT format. The GTT Address Maps define a global title address to be routed to using a specific routing indicator. These are configured in the global configuration mode and are available to all SCCP networks configured in the system.

1. In global configuration mode, create a GTT association with a unique name.
2. In GTT association configuration mode, define the type of digit analysis to be used; “fixed” is the generally used digit analysis and if specified, also define the length of the digits to be analyzed. This is represented using action IDs.
3. In GTT association configuration mode, define the GT format (1 to 4) for which the analysis needs to be applied.
4. In the GT format configuration mode, specify the numbering plan and the nature of address to be used. Note that a separate GTT association needs to be created for a combination of numbering plan, nature of address, and GT format.

   IMPORTANT:

   There are many different ways to configure a GTT association and the needs of every network are different. Please refer to the Global Title Translation Association Configuration Mode chapter in the Command Line Interface Reference for the commands available.
5. In global configuration mode, create a GTT address map, with a unique name, for a specific global title address.
6. In GTT address map configuration mode, associate a specific GTT association and the action ID.
7. In GTT address map configuration mode, define the routing indicator to be included in the Called-party Address in the out-going SCCP message along with the destination of the message using the option out-address.

   IMPORTANT:

   There are many different ways to configure a GTT Address Map and the needs of every network are different. Please refer to the GTT Address Map Configuration Mode chapter in the Command Line Interface Reference for the commands available.

Example Configuration

    configure

       global-title-translation
    association instance <inst#>

          action id <id> type <action_type> start-digit <num> end-digit <num>

          gt-format <format_num>

          exit

       global-title-translation
    address-map instance <inst#>

          associate gtt-association <assoc#> action id <id>

          gt-address <gt_addr_prefix>

          out-address <name>

             ssf <sub_svc_fld>

             routing-indicator <route_ind>

             ni-indicator <addr_ind>

             ssn <sub_sys_num>

             point-code <pt_code>

             end

## Configuring an SCCP Network

SCCP (Signaling Connection Control Part) networks are a concept specific to this platform. The SCCP network provides services to protocol layers higher in the SS7 protocol stack, e.g., RANAP and TCAP. This layer is also responsible for GTT. Every SS7 routing domain will be associated with an SCCP network. Use the following example configuration to specify a global SCCP configuration specific to SGSN services.

IMPORTANT:

A total of 12 SCCP networks can be configured.

To configure an SCCP network:

1. In global configuration mode, specify an identification number for this SCCP network configuration and the signaling variant.
2. Specify the self point code of the SGSN.
3. Specify the SS7 routing domain with which to associate this SCCP network configuration.
4. If using GTT (Global Title Translation), specify the name of a GTT address map to use.
5. Configure a destination point code and give it a name.
6. Configure the destination point code version.
7. Configure the destination point code subsystem number.

Example Configuration

    configure

       sccp-network <id_number> variant <v_type>

          self-pointcode <sp_code>

          associate ss7-routing-domain <rd_id>

          global-title-translation
    address-map <map_name>

          destination dpc <dp_code> name <name>

          destination dpc <dp_code> version <ver_type>

          destination dpc <dp_code> ssn <ss_number>

          end

## Configuring a MAP Service

The Mobile Application Part (MAP) is an SS7 protocol which provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to mobile phone users. MAP is the application-layer protocol used to access the Home Location Register (HLR), Visitor Location Register (VLR), Mobile Switching Center (MSC), Equipment Identity Register (EIR), Authentication Center (AUC), Short Message Service Center (SMSC) and Serving GPRS Support Node (SGSN).

The primary facilities provided by MAP are:

- Mobility Services: location management (when subscribers move within or between networks), authentication, managing service subscription information, fault recovery.
- Operation and Maintenance: subscriber tracing, retrieving a subscriber's IMSI.
- Call Handling: routing, managing calls while roaming, checking that a subscriber is available to receive calls.
- Supplementary Services.
- Short Message Service (SMS)
- Packet Data Protocol (PDP) services for GPRS: providing routing information for GPRS connections.
- Location Service Management Services: obtaining the location of subscribers.

IMPORTANT:

A maximum of 12 MAP services can be configured on the system.

To configure MAP services:

1. In the context config mode, create a MAP service and give it a name.
2. In MAP Service configuration mode, configure the SCCP network that defines SS7 connectivity for SCCP applications.
3. Configure the parameters to contact the HLR.
4. In HLR configuration mode, specify the HLR pointcodes that should be associated with specific IMSI prefixes.
5. Configure the HLR pointcode to use as the default.
6. Optional: Enable the Short Message Service functionality.
7. Optional: Configure the SMS routing.

Example Configuration

    configure

       context <context_name>

          map-service <map_name>

             access-protocol sccp-network <sccp_network_id>

             equipment-identity-register
    point-code <pnt_code>

             hlr

                imsi any point-code

                default policy routing

                exit

             short-message-service

                smsc-routing  imsi-starts-with <prefix> point-code <sms_pc>

                end

## Configuring an IuPS Service (3G only)

A set of parameters, in the IuPS service configuration mode, define the communication path between the SGSN service and the RNC. These configured parameters pertain to the RANAP layer of the protocol stack. IuPS services must be configured in the same context as the SGSN service that will use them.

To configure an IuPS service:

1. In context configuration mode for the SGSN service, create an IuPS service and give it a unique name.
2. In IuPS service configuration mode, specify the ID of the SCCP network to use for access protocol parameters.
3. Bind an address of an IP interface defined in the current context to use for GTPU connections to the RNC.
4. Specify an RNC to configure with a unique ID and the MCC and MNC associated with the RNC.
5. In RNC configuration mode, specify the RNCs point code.
6. Specify the LAC ID and RAC ID associated with the RNC.

   IMPORTANT:

   Appropriate interfaces (i.e., physical, loopback, secondary) must be defined prior to configuring the IuPS service or the GTP-U IP address will decline to bind to the service.

Example Configuration

    configure

       context <context_name>

          iups-service <iups_name>

             access-protocol sccp-network <sccp_network_id>

             gtpu bind address <ip_address>

             rnc id <rnc_id> mcc <mcc_num> mnc <mnc_num>

                pointcode <rnc_pc>

                lac <lac_id> rac <rac_id>

``end``

## Configuring an SGTP Service

This section provides instructions for configuring GPRS Tunneling Protocol (GTP) settings for the SGSN. At a bare minimum, an address to use for GTP-C (Control signaling) and an address for GTP-U (User data) must be configured.

To configure the SGTP service:

1. Create an SGTP service and give it a unique name, in context configuration mode.
2. Specify the IP address of an interface in the current context to use for GTP-C.
3. Specify the IP address of an interface in the current context to use for GTP-U.

   IMPORTANT:

   Appropriate interfaces (i.e., physical, loopback, secondary) must be defined prior to configuring the SGTP service or the GTP-U IP address will decline to bind to the service.

Example Configuration

    configure

       context <name>

          sgtp-service <name>

             gtpc bind address <address>

             gtpu bind address <address>

             end

## Configuring a Gs Service

This section provides instructions for creating and configuring a Gs interface used by the SGSN to communication with an MSC or VLR. The Gs interface is defined as a Gs service which handles the configuration for the MSC/VLR.

The Gs interface parameters are configured within a Gs service in a context. Then the Gs service is referred to in a GPRS service, an SGSN service, or an Call-Control Profile. The Gs service does not need to be in the same context as the SGSN service, GPRS service, or a Call-Control Profile.

To configure the Gs service:

1. In context configuration mode, create a Gs service and give it a unique name. Usually Gs service is defined in the same context in which MAP service is defined because the MSC/VLR, HLR, EIR, and SMS-C are reachable via the STP or SGW connected to the SGSN.
2. Specify the name of the SCCP network that identifies the SS7 access protocols.
3. Specify the target SS7 sub-system number (SSN), of the Base Station System Application Part (BSSAP), for communication. Without this bit of configuration, the Gs service can not start.
4. Identify a location area code, in either a pooled or non-pooled configuration, relevant to the MSC/VLR. This step can be repeated as needed.
5. Define the MSC/VLR by identifying its ISDN number, its SS7 point code, and the BSSAP SSN used to communicate with it. Repeat this step to define multiple MSC/VLRs. (Note: SSN only needs to be defined if the routing defined is to the MSC/VLR is PC+SSN.)

Example Configuration

    configure

       context <name>

          gs-service <name>

             associate-sccp-network <id>

             bssap+ ssn <ssn>

             non-pool-area <id> use-vlr <vlr_id> lac <lac_id>

             vlr <vlr_id> isdn-number <isdn_number> bssap+ ssn <ssn> point-code <vlr_pt_code>

             end

## Configuring an SGSN Service (3G only)

All the parameters specific to the operation of an SGSN in a UMTS network are configured in an SGSN service configuration. SGSN services use other configurations like MAP and IuPS to communicate with other elements in the network. The system can support multiple SGSN services.

To configure an SGSN service:

1. In Context configuration mode, create an SGSN service and give it a unique name.
2. Specify the Core Network (CN) ID that will identify this SGSN service on the CN.
3. Specify the E.164 number to identify this SGSN service.
4. Configure the maximum number of PDP contexts that a UE can establish.
5. Specify the MAP service and the context in which it is configured that this SGSN service should use.
6. Specify the IuPS service name and the context in which it is configured for the SGSN service to use for RAN protocol settings.

   IMPORTANT:

   If a direct tunnel is to be established, GTP-U direct tunneling must be enabled in both the IuPs service and in the call-control-profile. For the IuPS service, the DT must be enabled per RNC; DT is enabled by default on RNCs.
7. Specify the SGTP service and the context in which it is configured for this SGSN service to use for GTP configuration.
8. Specify the CDR types that the SGSN service should generate.
9. Specify the context in which GTPP accounting is configured. If the accounting context is not specified the current context is assumed.
10. Configure the charging characteristics profile. (Number of buckets for the max change condition, volume limit, time limit, and tariff time switch values should be defined individually according to requirements for each of the charging characteristics profiles.
11. Optional: Specify the Gs service name and the context in which it is configured.

    IMPORTANT:

    Session Management (SM) and GPRS Mobility Management (GMM) settings can be configured as needed using the SGSN configuration mode commands;sm <keyword> andgmm <keyword>. Refer to the SGSN Service Configuration Mode chapter in the GPRS/UMTS Command Line Interface Reference.

Example Configuration

    configure

       context <context_name>

          sgsn-service <svc_name>

             core-network id <cn_id>

             sgsn-number <sgsn_number>

             max-pdp-contexts per-ms <max_number>

             { mobile-application-part-service | associate
    map-service } <map_name> context <map_context>

             ran-protocol iups-service <iups_svc_name> context <iups_context>

             { sgtp-service | associate
    sgtp-service } <svc_name>
    context <name>

             accounting cdr-types [ mcdr | scdr ]

             accounting context <acct_context>

             cc profile <profile_number> interval <seconds>

             { gs-service context  | associate
    gs-service } <ctxt> service <gs_service_name>

             end

Notes:

- For releases 12.2 and earlier, use mobile-application-part-service <map_name> context <map_context> command. For releases 14.0 and later, use the associate map-service <map_name> context <map_context> command.
- For releases 12.2 and earlier, use the sgtp-service <svc_name> context <name> command. For releases 14.0 and later, use associate sgtp-service <svc_name> context <name> command.
- For releases 12.2 and earlier, use the gs-service context <ctxt> service <gs_service_name> command. For releases 14.0 and later, use the associate gs-service context <ctxt> service <gs_service_name> command.

## Configuring a GPRS Service (2.5G only)

All the parameters specific to the operation of an SGSN in a GPRS network are configured in a GPRS service configuration. GPRS services use other configurations like MAP and SGTP to communicate with other elements in the network. The system can support multiple GPRS services.

To configure a GPRS service:

1. In Context configuration mode, create a GPRS service instance and give it a unique name.
2. Specify the context in which the accounting parameters have been configured.
3. Create a PLMN definition for the GPRS service to include the identity of the mobile country code (MCC) and the mobile network code (MNC).
4. Associate other services (such as a MAP or Gs or SGTP service) and their configurations with this GPRS service. This command should be repeated to associate multiple service types and/or multiple instances.
5. Define the network service entity identifier (NSEI) of one or more remote SGSNs with their location area code (LAC) and routing area code (RAC). This step can be repeated to associate multiple peer-NSEIs.
6. Specify the E.164 number to identify this SGSN.
7. Configure the charging characteristic(s).
8. Specify the types of CDRs to generate.

Example Configuration

    configure

       context <context_name>

          gprs-service <gprs_service_name>

             accounting <ctxt>

             plmn id mcc <mcc_num> mnc <mnc_num>

             { service | associate
    service | }<service_type> <service_name> context <service_ctxt>

             peer-nsei <peer_nsei_id> lac <lac_id> rac <rac_id>

             sgsn-number <sgsn_isdn_number>

             cc profile <id> buckets <value>

             cc profile <id> interval <value>

             accounting cdr-types <cdr_type>

             end

Configuring a Network Service Entity

### Configure a Network Service Entity for IP

Prior to implementing this configuration, the IP interfaces should have been defined in the same context as the GPRS service.

1. In Global configuration mode, create a network service entity (NSE) for IP. The resulting prompt will appear as:

       [local]<hostname>(nse-ip-local)#

2. In the Network Service Entity - IP local configuration mode, create up to four virtual links (NSVLs) for this entity - each with a unique NSVL Id. The resulting prompt will appear as:

       [local]<hostname>(nse-ip-local-nsvl-<id>)#

3. Configure the link access information: IP address, context name, and port number.
4. Configure the links signaling characteristics.

Example Configuration for a Network Service Entity for IP

    config

       network-service-entity
    ip-local -n

          nsvl instance <id>

             nsvl-address ip-address <ip_addr> context <ctxt> port <num>

                signaling-weight <num> data-weight <num>

                end

### Configure a Network Service Entity for Frame Relay

1. In Global configuration mode, create a network service entity (NSE) for Frame Relay. The resulting prompt will appear as:

       [local]<hostname>(nse-fr-peer-nsei-id)#

2. In the Peer NSEI configuration mode, create a virtual connection instance for this entity. The resulting prompt will appear as:

       [local]<hostname>(nse-fr-peer-nsei-<id>-nsvci-<id>)#

Example Configuration for a Network Service Entity for IP

    config

       network-service-entity
    peer-nsei <id> frame-relay

          ns-vc id <id> -n

          end

## Configuring DNS Client

DNS client services can be configured for a context.

1. In context configuration mode, enable DSN lookup.
2. Specify the DNS to use for lookups; maximum of two DNS addresses can be used.
3. Create a DNS client with a unique name.
4. In DNS Client configuration mode, bind the DNS client to the IP address of an interface in the current context.

Example Configuration

    configure

       context <context_name>

          ip domain-lookup

          ip name-servers <ip_address>

          dns-client <name>

             bind address <ip_address>

             end

## Configuring GTPP Accounting Support

This section provides instructions for configuring GTPP-based accounting which allows the SGSN to send M-CDR and/or S-CDR accounting data to the Charging Gateways (CGs) over the Ga interface.

The Ga interface and GTPP functionality are typically configured within a separate charging context.

The SGSN begins to generate M-CDR data upon GPRS/IMSI attach. S-CDR data generation begins upon PDP context activation.

Accounting servers can be configured individually or as GTPP accounting server groups. GTPP accounting server groups can each have completely different GTPP settings configured. Although a GTTP server can be included in multiple GTPP groups.

Any GTPP accounting servers configured at the context level that are not specifically configured as part of a GTPP group, are automatically assigned to be part of the GTPP server group called default that is part of every context.

A maximum of 8 GTPP named server groups can be configured across all contexts. A maximum of 4 CGFs can be configured in each GTPP server group. A total of total 32 CGFs can be configured across all server groups, including the server group called default, in one context. Each GTPP group must have unique GTPP charging agents (CGFs) configured.

IMPORTANT:

The system supports the specification of the UDP port number for the charging agent function on the system and for the CG. The default charging agent port is 49999. The default CG Server port is (3386). If an SGSN service and a GGSN service are both configured on this system be sure that the UDP ports are unique for each type of service. Refer to the Command Line Interface Reference for information on changing the ports used.

To configure the GTPP accounting support for a SGSN service:

1. Create the GTPP group in accounting context by applying the example configuration in the Creating GTPP Group section.
2. Configure the charging agent and GTPP server (CGF) related parameters for the GTPP accounting support by applying the example configuration in the Configuring GTPP Group section.
3. Verify your GTPP group and accounting configuration by following the steps in the Verifying GTPP Group Configuration section.
4. Save your configuration to flash memory, an external memory device, and/or a network location using the Exec mode command save configuration. For additional information on how to verify and save configuration files, refer to the System Administration Guide and the Command Line Interface Reference.

Creating GTPP Group

Use the following example to create the GTPP group to support GTPP accounting:

    configure

       context <vpn_ctxt_name>

          gtpp group <gtpp_group_name>
    -noconfirm

          end

Notes:

- In addition to one default GTPP group “default” a maximum of 8 GTPP groups can be configured with this command in a context.
- In case no GTPP group is configured in this context, system creates a default GTPP group named “default” and all the CGF servers and their parameters configured in this context are applicable to this “default” GTPP group.

Configuring GTPP Group

Use the following example to configure the GTPP server parameters, GTPP dictionary, and optionally CGF to support GTPP accounting:

    configure

       context <vpn_ctxt_name>

          gtpp group <gtpp_group_name>

             gtpp charging-agent
    address <ip_address> [ port <port> ]

             gtpp server <ip_address> [ max <msgs >] [ priority <priority>]

             gtpp dictionary <dictionaries>

             gtpp max-cdrs <number_cdrs> [ wait-time <dur_sec> ]

             gtpp transport-layer { tcp | udp }

             end

Notes:

- In addition to one default GTPP group “default” a maximum of 8 GTPP groups can be configured with this command in a context.
- In case no GTPP group is configured in this context, system creates a default GTPP group named “default” and all the CGF servers and their parameters configured in this context are applicable to this “default” GTPP group.
- Command for CGF gtpp charging-agent is optional and configuring gtpp charging-agent on port 3386 may interfere with ggsn-service configured with the same ip address. Multiple interfaces can be configured within a single context if needed.
- For more information on GTPP dictionary encoding, if you are using StarOS 12.3 or an earlier release, refer to the AAA and GTPP Interface Administration and Reference. If you are using StarOS 14.0 or a later release, refer to the GTPP Interface Administration and Reference.
- For better performance, it is recommended to configure maximum number of CDRs as 255 with gtpp max-cdrs command.
- You can select transport layer protocol as TCP or UDP for Ga interface with gtpp transport-layer command. By default it is UDP.
- Multiple GTPP server can be configured using multiple instances of this command subject to following limits:
  - Total 4 GTPP server in one GTPP group
  - Total 32 GTPP server in one context
  - Total 9 GTPP groups (1 default and 8 user defined GTPP groups) can be configured in one context. Number of CGFs in 1 GTPP group is limited to 4 and a total of 32 CGF servers across all GTPP groups in one context are configurable.

### Verifying GTPP Group Configuration

1. Verify that your CGFs were configured properly by entering the following command in Exec Mode:

       show gtpp accounting
       servers

   This command produces an output similar to that displayed below:

       context: source

       Preference   IP                Port   Priority     State         Group

       ----------  ---------------    ----   --------    -------       ------

       Primary     192.168.32.135     3386          1     Active       default

       Primary     192.168.89.9       3386        100     Active       default

## Configuring and Associating the EGTP Service (S4 Only)

This section describes how to configure and associate the EGTP service to support S4-SGSN functionality.

The SGSN communicates with the EPC network SGW via the GTPv2 protocol over the S4 interface. GTPv2 is configured on the chassis as part of an EGTP service. Once configured, the EGTP service then must be associated with the configured UMTS (3G) and/or GPRS (2G) service configured on the system to provide access to the EPC network.

Once the EGTP service is associated with the UTRAN and/or GERAN service, then the S4-SGSN will be chosen for PDP context activation in the following cases:

- If the last known capability of the UE indicates that it is EPC-capable.
- If a PDP context is already activated for the UE, and the S4 interface is already selected for the UE.

IMPORTANT:

The S4 feature license must be enabled on the S4-SGSN to configure the EGTP service.

IMPORTANT:

S4 support for the SGSN requires the presence of an SGTP service, even though S4 support is being configured for the SGSN to use the S4 interface. The SGTP service is required to interface with non-EPC capable roaming partners via the Gn interface. SGTP is also required for subscribers using mobile phones that are not EPC-capable in an EPC network.

IMPORTANT:

Currently, the S4-SGSN does not support the transfer of PDP contexts from the S4 interface to the Gn interface within the same S4-SGSN.

Use the following procedure to configure and associate the EGTP service to for S4 functionality on the SGSN:

1. Access Context Configuration Mode.
2. Create and configure the EGTP service in the desired context.
3. Configure the interface type for the EGTP service.
4. Configure the validation mode for the EGTP service. The default is standard.
5. Associate the EGTP service with the configured 2.5G service (if configured).
6. Associate the EGTP service with the configured 3G service (if configured).

Example Configuration

    config

       context <context_name>

          egtp-service <service_name>

             gtpc { bind { ipv4-address <ipv4_address> [ ipv6-address <ipv6_address> ] }

             interface-type interface-sgsn

             validation-mode { custom1 | standard }

             end

    config

       context <context_name>

          gprs-service <gprs_service_name>

             associate egtp-service <egtp_service_name> [ context <context_name> ]

             end

    config

       context <context_name>

          sgsn-service <sgsn_service_name>

             associate egtp-service <egtp_service_name> [ context <context_name> ]

             end

## Configuring the DNS Client Context for APN and SGW Resolution (Optional)

This section describes how to configure the context from which DNS client has to be selected for performing an APN FQDN query for resolving a PGW address (S4-SGSN) or a co-located PGW / GGSN address (Gn SGSN), and the context from which DNS client has to be selected for performing an RAI FQDN query for resolving an SGW address (S4-SGSN).

By default, the S4-SGSN supports the initiation of a DNS query after APN selection using a S-NAPTR query. The S4-SGSN resolves a PGW by sending an APN-FQDN query to the DNS client. Similarly, the S4-SGSN resolves the SGW by sending a RAI-FQDN query to the DNS client. The DNS Client then sends a query to the DNS server to retrieve NAPTR/SRV/A records and return the SGW or PGW IP address to the SGSN.

The Gn SGSN supports selecting a co-located PGW/GGSN node for EPC capable UEs by performing a DNS SNAPTR lookup for APN FQDN for the service parameter x-3gpp-pgw:x-gn.

For performing a DNS SNAPTR query, the SGSN requires an additional, optional, configuration that identifies the context where DNS lookup for EPC-capable UEs must occur. This is accomplished by creating a call-control-profile that specifies the context from which the DNS client should be used for resolving a co-located PGW/GGSN address on a Gn SGSN as well.

Use the following procedure to configure and associate the configure DNS for APN resolution to support S4 functionality:

1. Access Call Control Profile Configuration Mode and create a call control profile.
2. Configure the DNS client context to resolve PGW UEs via the context the DNS client is configured.
3. Configure the DNS client context to resolve SGW UEs via the context where the DNS client is configured.

Example Configuration

    config

        call-control-profile <name>

          dns-pgw context <dns_client_context_name>

          dns-sgw context <dns_client_context_name>

          end

Notes:

- dns-pgw context is valid for selecting a PGW (in an S4-SGSN) as well as a co-located PGW/GGSN (in a Gn SGSN). If the interface selected for a UE is S4 and if there is no dns-pgw context configured under the Call Control Profile, then by default it will look for the DNS client in the context where the EGTP service is defined. If the interface selected for a UE is gn-gp, and if there is no dns-pgw context configured under the Call Control Profile, then by default the system will look for the DNS client in the context where the SGTP service is configured for selecting co-located PGW/GGSNs if:
  - The UE is EPC capable and,
  - apn-resolve-dns-query snaptr is configured under an APN Profile.
- dns-sgw context specifies the name of the context where the DNS client is configured and that will be used for DNS resolution of SGWs. If dns-sgw is not configured, the S4-SGSN uses the DNS client configured in the context where EGTP service is configured to query the SGW DNS address.

## Configuring the S6d Diameter Interface (S4 Only)

This section describes how to configure the S6d Diameter interface to support S4 functionality.

The S6d interface is a Diameter-based interface used to support S4 functionality by enabling the S4-SGSN to communicate with the HSS. The HSS is a master user database that contains all subscription related information, and performs the following functions:

- Authentication and authorization of the user
- Provides the subscribers location information
- Provides the subscribers IP information

To support the S6d interface, an HSS Peer Service must be configured and associated with a Diameter endpoint. This HSS Peer Service is then associated with the configured SGSN and/or GPRS services to enable communication with the HSS via the S6d interface. Optionally, operators can configure an operator policy-based interface selection.

Configuring the S6d interface consists of the following procedures:

1. Configuring a Diameter Endpoint for the S6d interface
2. Configuring the HSS Peer Service and Interface Association for the S6d interface
3. Associating the HSS Peer Service with the SGSN and GPRS Services for the S6d interface.
4. Optional. Configuring operator policy-based interface selection for the S6d interface.

### Configuring the Diameter Endpoint for the S6d Interface

Use the following procedure to configure the Diameter endpoint for the S6d interface:

1. Configure a port that will be bound to an interface (at step 3) to be used as the S6d interface.
2. Configure an Ethernet interface to be used as a diameter endpoint.
3. Configure a Diameter endpoint to be used as the S6d interface.
4. Specify the origin host address and the IP address of the Ethernet interface to be used as the S6d interface.
5. Specify the origin realm. The realm is the Diameter identity. The originator’s realm is present in all Diameter messages and is typically the company or service provider’s name.
6. Specify the peer name, peer realm name, peer IP address and port number. The peer IP address and port number are the IP address and port number of the HSS.
7. Specify the route entry peer. This parameter is optional. The route entry peer parameter is required if multiple HSS peers are configured under a Diameter point and operators want to associate a routing weight to each HSS peer so that the S4-SGSN contacts each HSS based on the weight distribution.
8. Optional. Enable or disable the watchdog-timeout parameter.
9. The use-proxy keyword can be specified in the diameter-endpoint command to enable the proxy mode. The usage of proxy mode depends on the operator’s HSS capabilities.

Example Configuration

    config

       port
    ethernet <slot number/port
    number>

          no shutdown

          bind
    interface <s6d_interface_name>
    <context_name>

          end

    config

       context <context_name>

          interface <s6d_interface_name>

             ip
    address <s6d_interface_ip_address> <subnet_mask>

             exit

          diameter endpoint <endpoint_name>

             origin host <host_name> address <s6d_interface_ip_address>

             origin realm <realm_name>

             peer <peer_name> realm <realm_name> address <hss_ip_address>

             route-entry peer <route_entry_name>

             use-proxy

             no
    watchdog-timeout

             end

### Configuring the HSS Peer Service and Interface Association for the S6d Interface

Use the following procedure to configure the HSS Peer Service and interface association for the S6d interface:

1. Configure a Diameter endpoint. If not already configured, refer to the Configuring the Diameter Endpoint for the S6d Interface. Then specify the IP address of the Ethernet interface configured in Step 1 as the Diameter endpoint address.
2. Associate the Diameter endpoint with an HSS peer service.
3. Specify the Diameter dictionary to be used for the HSS Peer Service. The standard-r9 dictionary must be used for the S6d interface.

Example Configuration

    config

       context <sgsn_context_name>

          hss-peer-service <hss_peer_service_name>

             diameter hss-endpoint <hss_endpoint_name>

             diameter hss-dictionary standard_r9

             end

### Associating the HSS Peer Service with the SGSN and GPRS Services for the S6d Interface

Use this procedure to association the HSS Peer Service with the SGSN and GPRS Services:

1. Access Context Configuration Mode and create an SGSN service.
2. Associate the HSS peer service name with the SGSN service.
3. Access Context Configuration Mode and create a GPRS service.
4. Associate the HSS peer service name with the GPRS service.

Example Configuration

    config

       context <context name>

          sgsn-service <sgsn-service-name>

             associate hss-peer-service <hss-peer-service-name>

             end

    config

       context <context name>

          gprs-service <gprs-service-name>

             associate hss-peer-service <hss-peer-service-name>

             end

### Configuring Operator Policy-Based S6d Interface Selection (Optional)

It is mandatory for the SGSN and GPRS services to have either a MAP service association or an HSS-Peer-Service association.

- If no MAP service is associated with the SGSN or GPRS services, and only the HSS service is associated with the SGSN or GPRS services, then the S6d interface is selected.
- If both the MAP service and the HSS-Peer-Service are associated with the SGSN or GPRS service, by default the Gr interface is selected. To override the default use of the Gr interface, configure the operator policy to select the s6d-interface.
- Once the interface selection is configured, the call-control-profile is first checked to determine whether to select the MAP-interface or HSS-interface. If neither the MAP nor HSS is configured under the call control profile, then the system checks the configured SGSN or GPRS-services.

1. Access Call Control Profile Configuration Mode and create a call-control-profile.
2. Associate the configured HSS peer service with the S6d interface. The s6d-interface option must be selected.

Example Configuration

    config

       call-control-profile <name>

          associate hss-peer-service <name> s6d-interface

          end

### Configuring the Subscription Interface Preference for the S6d Interface (Optional)

The S4-SGSN provides a mechanism to associate a MAP service with call-control-profile. In some situations, it is possible that both the MAP service and the HSS peer service are associated with the Call Control Profile. In these cases, operators can configure the preferred subscription interface.

1. Access Call Control Profile Configuration Mode and create a call-control-profile.
2. Specify the preference of the subscription-interface. Selecting the hlr option will cause the MAP protocol to be used to exchange messages with the HLR. The hss option causes the Diameter-protocol to be used to exchange messages with the HSS.

Example Configuration

    config

       call-control-profile <name>

          prefer subscription-interface { hlr | hss }

          end

## Configuring the S13’ Interface (S4 Only)

The S13' (S13 prime) interface is a Diameter-based interface that is used to the perform Mobile Equipment (ME) identity check procedure between the SGSN and EIR.

The SGSN performs ME identity check to verify the Mobile Equipment’s identity status.

The S13‘interface uses Diameter protocol. An HSS Peer Service must be configured and associated with a Diameter endpoint. It is not mandatory to configure the HSS Peer Service under the SGSN or the GPRS service. By configuring the HSS Peer Service in Call Control Profile Configuration Mode, the S13‘interface can be used.

In the absence of an operator policy, the HSS Peer Service must be associated with the configured SGSN or GPRS service to be able to utilize the S13‘interface. In the presence of an operator policy, the operator policy configured overrides the service configured in the SGSN or GPRS service.

IMPORTANT:

The S13’ interface can only be configured after the S6d interface has been configured. Refer to Configuring the S6d Diameter Interface (S4 Only) procedure for information on configuring the S6d interface.

Configuring the S13’ interface consists of the following procedures;

1. Configure a Diameter Endpoint for the S13’ interface.
2. Configure the HSS Peer Service and Interface association for the S13’ interface.
3. Associate the HSS Peer Service with the SGSN and GPRS services for the S13’ interface.
4. Optional. Configure an operator policy S13-based interface selection call control profile for the S13’ interface.

### Configuring a Diameter Endpoint for the S13’ Interface

Use this procedure to configure a Diameter endpoint for the S13’ interface:

1. Access Context Configuration Mode and create a Diameter endpoint.
2. Specify the origin host address and the IP address of the S13‘interface.
3. Specify the origin realm. The realm is the Diameter identity. The originator’s realm is present in all Diameter messages and is typically the company or service name.
4. Specify the peer name, peer realm name, peer IP address and port number. The peer IP address and port number are the IP address and port number of the HSS.
5. Specify the route entry peer (optional). The route entry peer parameter is required if multiple HSS or EIR peers are configured under a Diameter point and operators wish to associate a routing weight to each HSS or EIR peer so that SGSN contacts each HSS or EIR based on the weight distribution.
6. The user can optionally enable or disable the parameter watchdog-timeout.
7. The use-proxy keyword can be specified in the diameter-endpoint command to enable the proxy mode. The usage of proxy mode depends on the operator’s EIR capabilities.

Example Configuration

    config

       port
    ethernet <s13’_interface_name>

          no shutdown

          bind
    interface s13’_interface_name>
    <sgsn_context_name>

          end

    config

          context <context_name>

             interface s13’_interface_ip>
    <subnet_mask>

                exit

             diameter endpoint <s13’_endpoint_name>

                origin host <host_name> address <host_address>

                origin realm <realm_address>

                peer <peer_name> realm <realm_name
    > address <hss_ip_address>

                route-entry peer <route_entry_name>

                use-proxy

                no watchdog-timeout

                exit

             hss-peer-service <hss_peer_service_name>

                diameter hss-endpoint <s6d_endpoint_name> eir-endpoint <s13’_endpoint_name>

                end

### Configuring the HSS Peer Service and Interface Association for the S13’ Interface

Use the following procedure to configure the HSS Peer Service and Interface association:

1. Configure an Ethernet interface to be used as a Diameter endpoint.
2. Configure a Diameter endpoint and specify the IP address of the Ethernet interface configured in Step 1 as the Diameter endpoint address.
3. Configure an HSS peer service and associate it with the Diameter endpoint configured for the S6d and S13’ interfaces.
4. Specify the Diameter dictionary to be used for the HSS-Peer-Service. The standard-r9 option must be selected for the SGSN.

Example Configuration

    config

       port ethernet <slot_number/port_number>

          no shutdown

          bind
    interface <s6d_interface_name> <sgsn_context_name>

          end

    config

       context <sgsn_context_name>

          interface <s6d_interface_name>

             ip address <s6d_interface_ip_address> <subnetmask>

             exit

          diameter endpoint <s6d-endpoint_name>

             origin realm <realm_name>

             origin host <name> address <s6d_interface_address>

             peer <peer_name> realm <realm_name> address <hss_ip_address>

             exit

          diameter endpoint <s13’_endpoint_name>

             origin realm <realm_name>

             origin host <name> address <s13’_interface_address>

             peer <peer_name> realm <realm_name>address <eir_ip_address>

             exit

          hss-peer-service <hss_peer_service_name>

             diameter hss-endpoint <hss_endpoint_name> eir-endpoint <eir_endpoint_name>

             diameter hss-dictionary standard-r9

             end

### Associating the HSS Peer Service with the SGSN and GPRS Services for the S13’ Interface

Use this procedure to associate the HSS Peer Service with the SGSN and GPRS services.

1. In Context Configuration Mode create a SGSN service.
2. Associate the HSS peer service with SGSN service, if configured, and provide the HSS peer service name and context name.
3. Associate the HSS peer service with GPRS service, if configured, and provide the HSS peer service name and context name.

Example Configuration

    config

       context <context_name>

          sgsn-service <sgsn_service_name>

             associate hss-peer-service <hss-peer-service-name>

             end

    config

       context <context_name>

          gprs-service <gprs_service_name>

             associate hss-peer-service <hss-peer-service-name>

             end

### Configuring S13’ Interface Selection Based on an Operator Policy

It is mandatory for the SGSN and GPRS service to have either a MAP service association or an HSS Peer Service association.

- In the absence of a MAP service association with SGSN or GPRS service, and if the HSS service is associated with the SGSN or GPRS service then the S13‘ interface is selected.
- If both the MAP service and the HSS-Peer-Service are associated with the SGSN or GPRS service, by default the Gf interface is selected. To override this default, operators can configure an operator policy to configure behavior for the S13’ interface selection.
- Once configured, the behavior is as follows:
  - First, the call control profile is checked to determine on whether a MAP or HSS interface is configured.
  - If neither A MAP or HSS is configured under the call control profile, then the system uses the configuration in the SGSN or GPRS service.

Use this procedure to configure an operator policy used for S13’ interface selection.

1. Access Call Control Configuration Mode and configure a call-control-profile.
2. Associate the HSS Peer Service with the s13-prime-interface.

Example Configuration

    config

       call-control-profile <name>

          associate hss-peer-service <name> s13-prime-interface

          end

## Configuring QoS Mapping for EPC-Capable UEs using the S4 Interface (S4 Only)

An S4-SGSN communicates QoS parameters towards the SGW and PGW in EPC QoS. However, it sends QoS towards the UE in the QoS format defined in the GMM/SM specification (TS 24.008). 3GPP defines a mapping for EPS QoS to pre-release 8 QoS in TS 23.401, Annex E. On the S4-SGSN, operators can configure the quality of service (QoS) parameters as Call Control Profiles that will ensure proper QoS mapping between the S4-SGSN and the EPC gateways (PGW and SGW) and UEs. However, such configurations are optional. If no mapping is configured, then the S4-SGSN uses the default mapping.

The configured Call Control Profiles also will be used if the S4 interface is chosen for PDP activation, but the subscription does not have an EPS subscription. Therefore, GPRS subscription data (which uses QoS in pre-release 8 format), will be mapped to EPS QoS behavior. The allocation and retention policy will be mapped to EPS ARP using the configured Call Control Profiles. Specifically, the configuration provided in this section enables the S4-SGSN to:

- Map EPC ARP (allocation and retention priority) parameters to pre-release 8 ARP (Gn/Gp ARP) parameters during S4-SGSN to Gn SGSN call handovers.
- Map ARP parameters received in a GPRS subscription from the HLR to EPC ARP parameters if the S4 interface is selected for an EPC capable UE that has only a GPRS subscription (but no EPS subscription) in the HLR / HSS.

If the QoS mapping configuration is not used, the following default mappings are used:

- Default ARP high-priority value = 5
- Default ARP medium-priority value = 10
- Default pre-emption capability = shall-not-trigger-pre-emption
- Default pre-emption vulnerability = pre-emptable

Use this procedure to configure QoS mapping for EPC Gateways and UEs:

1. Access Call Control Profile Configuration Mode and create a call-control-profile.
2. Configure the QoS ARP settings.
3. Exit back to the Local prompt and re-access Call Control Profile Configuration Mode.
4. Create a second call-control-profile.
5. Configure the QoS pre-emption or vulnerability capabilities.

Example Configuration

    config

       call-control-profile <cc_profile_name>

          qos gn-gp arp high-priority <hi_prior_value> medium-priority <med_prior_value>

          end

    config

       call-control-profile <cc-profile-name>

          qos gn-gp  pre-emption { capability { may-trigger-pre-emption | shall-not-trigger-pre-emption } | vulnerability { not-pre-emptable | pre-emptable } }

          end

## Configuring the Peer SGSN Interface Type (S4 Only, Optional)

Operators can specify the type of interface the S4-SGSN will use to communicate with the peer SGSN in a call control profile.

Use the following procedure to configure the peer SGSN interface type:

1. Access the Call Control Profile configuration for the peer SGSN.
2. Configure the interface type to be used for communication between the S4-SGSN and the peer SGSN. s16 must be specified if the peer SGSN is an S4-SGSN.

Example Configuration

    config

       call-control-profile <cc_profile_name>

          sgsn-address rac <rac value> lac <lac value> [nri <val> ] prefer { local | fallback-for-dns} address ipv4 <ipv4 addr> interface { gn | s16 }

          end

Note:

- The fallback-for-dns option is under development for future use, and is not currently supported on the S4-SGSN.

## Configuring Gn Interface Selection Based on an Operator Policy (S4 Only, Optional)

By default, the S4-SGSN uses the S4 interface to communicate with EPC-capable UEs. However, operators have the to option to create a call-control-profile that enables the S4-SGSN to forcefully select the Gn interface for EPC capable UEs.

Use this procedure to forcefully select the Gn interface for EPC-capable UEs:

1. Access Call Control Profile Configuration Mode.
2. Create a call-control-profile.
3. Configure the SGSN to forcefully select the Gn interface.

Example Configuration

    config

       call-control-profile <cc_profile_name>

          sgsn-core-nw-interface { gn | s4 }

          end

Note:

- sgsn-core-nw-interface specifies the interface that EPC-capable UEs will use to communicate with the packet core gateways (GGSN/SGW). The default setting for EPC-capable UEs is s4.

## Configuring a Custom MME Group ID (S4 Only, Optional)

3GPP specifications define how a GUTI allocated by an MME is translated into an old P-TMSI and old RAI when a UE hands over to an SGSN. 3GPP specifications state that when a GUTI is mapped to an old RAI, the MME group ID portion of the GUTI will be mapped to a Location Area Code (LAC). MME group IDs are 16-bit numbers which always have their most significant bit set. As a result, their range is 32768 - 65535.

However, some operators may have already configured their networks with LACs for UTRAN and GERAN coverage in the 32768 - 65535 range. To provide backward compatibility for such deployments, a custom list of MME group IDs must be configured for use by both the S4-SGSN and MME products for UTRAN/GERAN and E-UTRAN handovers.

Once the custom MME Group IDs have been configured, operators then can configure the S4-SGSN to use the available custom MME Group IDs configured for both GPRS (2G) and UTRAN (3G) network services.

Use the following procedure to configure the SGSN to use the custom MME Group IDs:

1. Access LTE Network Global MME ID Management Database Configuration Mode.
2. Specify the PLMN MCC and MNC values.
3. Configure the low and high end values of the LAC range to be used.
4. Access the context in which the SGSN (3G) service is configured.
5. Associate the 3G service (if configured), with the MME’s Network Global MME ID Management Database that contains the custom list of MME Group IDs.
6. Access the context in which the 2G GPRS service is configured.
7. Associate the 2G service, if configured, with the MME’s Network Global MME ID Management Database that contains the custom list of MME Group IDs.

Example Configuration

    config

       lte-policy

          network-global-mme-id-mgmt-db

             plmn
    mcc <mcc_value> mnc <mnc_value> mme-group-id-range first           <low_end_of_range> last <high_end_of_range>

             exit

          exit

       context <context_name>

          sgsn-service <sgsn_service_name>

             associate network-global-mme-id-mgmt-db

             end

    config

       context <context_name>

          gprs-service <gprs_service_name>

             associate network-global-mme-id-mgmt-db

             end

## Configuring and Associating the Selection of an SGW for RAI (S4 Only, Optional)

If operators wish to bypass DNS resolution of RAI FQDN for obtaining the S-GW address, the SGSN can select an S-GW by performing a local configuration look-up for the current Routing Area Instance (RAI). This is accomplished by configuring the SGSN to select an S-GW address and its associated RAI. In addition, the 2G and/or 3G services configured on the SGSN must be associated with the S-GW addresses and associated RAIs. The services can also be associated with an operator policy for RAI-to-SGW address mapping.

Use the following procedure to configure the selection of an SGW for RAI:

1. Access Global Configuration Mode.
2. Access LTE Policy Configuration Mode.
3. Create a TAI Management Database and enter TAI Management Database Configuration Mode.
4. Create a TAI Management Object and enter TAI Management Object Configuration Mode.
5. Configure the RAI. Specify the RAI MCC, MNC, LAC and RAC values.
6. Configure the SGW address serving the RAI. Specify the IPv4 or IPv6 address, the S5-to-S8 protocol as GTP, and the load balancing Weight for this SGW. On the S4-SGSN, only GTP is supported as the protocol option.
7. Access SGSN Service Configuration Mode and associate the configured UTRAN (3G) service with the S-GW addresses and their associated RAIs.
8. Access GPRS Service Configuration Mode and associate the configured GERAN (2G) and service with the S-GW addresses and their associated RAIs.
9. Optional. Associate the SGW address-to-RAI mapping with an operator policy.

Example Configuration

    config

       lte-policy

          tai-mgmt-db <tai_mgmt_db_name>

             tai-mgmt-ojb <obj_name>

                rai mcc <mcc_value> mnc <mnc_value> lac <lac_value> rac <rac_value>

                sgw-address <ipv4_addr> | <ipv6_addr> s5-s8-protocol gtp weight             <number>

                end

    config

       context <context_name>

          sgsn-service <sgsn_service_name>

             associate tai-mgmt-db <tai_mgmt_db_name>

             end

    config

       context <context_name>

          gprs-service <gprs_service_name>

             associate tai-mgmt-db <tai_mgmt_db_name>

             end

    config

       call-control-profile <cc_profile_name>

          associate tai-mgmt-db <tai_mgmt_db_name>

          end

## Configuring a Local PGW Address (S4 Only, Optional)

If operators wish to bypass DNS resolution of APN FQDN on the S4-SGSN for obtaining a PGW address, the S4-SGSN can be configured to use a locally configured PGW IPv4 address in an APN profile.

Use the following procedure to configure the local PGW address:

1. Access APN Profile Configuration Mode and create an APN profile.
2. Specify the address resolution mode for the PGW as local.
3. Configure the P-GW address.
4. Configure the load balancing weight preference for the P-GW.

Example Configuration

    config

       apn-profile <apn_profile_name>

          address-resolution-mode local

          pgw-address <ipv4_address | ipv6_address> weight <weight_preference>

          end

## Configuring the Peer MME Address (S4 Only, Optional)

For operators wishing to bypass DNS resolution to obtain the peer EPC MME address, the SGSN supports the local configuration of a peer MME address for a given MME group (LAC) and MME code (RAC).

Use the following procedure to configure the peer MME address:

1. Access Call Control Configuration Mode and create a call-control-profile.
2. Configure the peer MME Group ID LAC and RAC values.
3. Specify a local preference for selection of the peer MME address.
4. Specify the local MME address to use for lookup instead of a DNS query.
5. Specify the interface type to use when communicating with the peer MME. The interface must be s3.

Example Configuration

    config

       call-control-profile <cc-profile-name>

          peer-mme mme-groupid  <lac_value> mme-code  <rac_code>  prefer local address <ipv4_address | ipv6_address> interface { gn [ s3 ] | s3 [ gn ] }

          end

## Configuring the ISR Feature (S4 Only, Optional)

Idle Mode Signaling Reduction (ISR) is a license-enabled feature that allows the UE to roam between LTE and 3G networks while reducing the frequency of TAU and RAU procedures due to the UE selecting E-UTRAN or UTRAN networks. ISR reduces the signaling between the UE and the network, and also reduces the signaling between the E-UTRAN and UTRAN networks.

IMPORTANT:

Currently, the ISR feature is supported for 3G (UMTS) networks only.

Use the following procedure to configure the ISR feature:

1. Access Call Control Configuration Mode.
2. Create a call-control-profile.
3. Enable the Idle Mode Signaling Reduction feature for 3G (UMTS) network access
4. Set the T3323 timeout value that the configured SGSN service will send to the UE in Attach Accept and RAU Accept messages.

Example Configuration

    config

       call-control-profile <cc-profile-name>

          idle-mode-signaling-reduction
    access-type umts

          end

    config

       context <context_name>

          sgsn-service <sgsn_service_name>

             gmm T3323-timeout <dur_mins>

             end

Note:

- This command specifies that the Idle Mode Signaling Reduction deactivation timer will be sent to the UE.
- <dur_mins> is the amount of time, in minutes, the UE should wait after the Periodic RAU timer (T3312 timer) expiry before deactivating ISR. Valid entries are from 1 to 186. The default is 54.

## Configuring IDFT for Connected Mode Handover (S4 Only, Optional)

The S4-SGSN supports the setup of indirect data forwarding tunnels (IDFT) between the eNodeB and the RNC via the SGW during connected mode handovers. This allows the S4-SGSN to support connected mode handovers between the UTRAN and E-UTRAN networks across the S3 interface.

Once enabled, IDFT is employed under the following conditions:

- If the SGSN is the old node participating in the connected mode handover:
  - The target node to which the connected mode handover is initiated should be an eNodeB (i.e., the SGSN performs the handover to the MME.
  - The enb-direct-data-forward CLI setting is not configured in the target RNC configuration (in RNC Configuration Mode).
- If the SGSN is the new node participating in the connected mode handover:
  - The source node from which connected mode handover is initiated is an eNodeB (i.e., the MME is performing a handover to the SGSN).
  - The enb-direct-data-forward CLI setting is not configured in the target RNC configuration (in RNC Configuration Mode).
  - The source MME indicated that it does not support direct forwarding via a Forward Relocation Request.
  - The target SGSN did not relocate to a new SGW. The target SGSN sets up an indirect data forwarding tunnel with the SGW only if the SGW is relocated. If the SGW is not relocated, then it is the source MME that will set up the indirect data forwarding tunnel between the source eNodeB and the target RNC through the SGW

IMPORTANT:

By default, indirect data forwarding is enabled, and direct forwarding is disabled.

To configure IDFT for connected mode inter RAT handovers:

1. Enter the context where the IuPS service is configured.
2. Enter IuPS Service Configuration Mode and enter the configured IuPS service.
3. Enter the RNC ID of the IuPS service for which you want to enable IDFT.
4. Disable direct data forwarding for connected mode inter RAT handovers.

Example Configuration

    config

       context <context_name>

          iups-service <iups_service_name>

             rnc id <rnc_id>

                no enb-direct-data-forward

                end

Where:

- no enb-direct-data-forward enables the setup of IDFT between the eNodeB and the SGW for connected mode inter RAT handovers.
- To disable IDFT, enter the enb-direct-data-forward command.

Creating and Configuring ATM Interfaces and Ports (3G only)

ATM ports and their associated PVCs can be configured for use with point-to-point interfaces and defined in a context or they can be bound to link IDs defined in SS7 routing domains.

Refer to the chapter titled System Element Configuration Procedures in the System Administration Guide for information on configuring ATM interfaces.

Creating and Configuring Frame Relay Ports (2.5G only)

Frame Relay ports and their associated DLCIs can be configured for communication with 2G Base Station subsystem (BSS) for an SGSN implementation.

Refer to the chapter titled System Element Configuration Procedures in the System Administration Guide for information on configuring Frame Relay ports.

## Configuring APS/MSP Redundancy

ASP/MSP redundancy is only available for the OLC2 and CLC2 line cards. It is setup per linecard -- all ports share the same setup.

APS is enabled with the redundancy command in the Card configuration mode.

IMPORTANT:

At this time the aps command in the Card Configuration Mode chapter is still in development and should not be used. The parameters are all set by default and cannot be changed or disabled.

- Related configuration for signal degrade and signal failure bit error rate thresholds for high path, low path, and transport overhead - use the commands in the Port Channelized configuration mode.

For command details, refer to the Card Configuration Mode Commands chapter and the Port Configuration Mode Commands chapter in the Cisco UMTS Command Line Interface Reference.

1. Configure a line card for either SONET or SDH.
2. Configure APS for a SONET line card or MPS for an SDH line card. Use the configuration example below:

Example Configuration

Use the following example (replacing specific values) to setup a CLC2 (Frame Relay) line card:

    config

       card
    27

          framing
    sdh e1

          header-type
    4-byte

          initial-e1-framing
    standard

          redundancy
    aps-mode

          service-type
    frame-relay

          no
    shutdown

          end