SGSN Service Configuration Procedures


SGSN Service Configuration Procedures
 
This chapter provides configuration instructions to enable the SGSN to function in either GPRS (2.5G) or UMTS (3G) networks. The System Administration Guide provides interface and system-level configuration details and the Command Line Interface Reference provides additional command information.
High level step-by-step service configuration procedures are provided for the following:
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:
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”.
Step 1
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Step 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.
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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 SystemAdministration Guide.
Step 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.
Step 1
Create the contexts needed. Refer to the System Element Configuration Procedures chapter in the System Administration Guide.
Step 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.
Step 3
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Configure ATM PVCs and bind them to interfaces or SS7 links as needed. Refer to Creating and Configuring ATM Interfaces and Ports in the SystemAdministration Guide.
Step 13
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:
Step 1
Create the contexts needed. Refer to the System Element Configuration Procedures chapter in the System Administration Guide.
Step 2
Create any interfaces needed in the appropriate context refer to the System Element Configuration Procedures chapter in the System Administration Guide.
Step a
For IP (broadcast Ethernet) interfaces, refer to Creating and Configuring Ethernet Interfaces and Ports in the System Administration Guide..
Step b
For ATM interfaces (3G) refer to Creating and Configuring ATM Interfaces and Ports in the System Administration Guide.
Step c
For Frame Relay interfaces (2.5G) refer to Creating and Configuring Frame Relay Interfaces and Ports in the System Administration Guide.
Step 3
Step 4
Step 5
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Step 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 SystemAdministration Guide.
Step 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 SystemAdministration Guide..
Step 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 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
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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:
Step 1
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Important: At least one address needs to be configured before the end-point can be activated.
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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.
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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.
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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
      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:
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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:
Important: A maximum of 12 MAP services can be configured on the system.
To configure MAP services:
Step 1
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Optional: Enable the Short Message Service functionality.
Step 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:
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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:
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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:
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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:
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Important: GTP-U Direct Tunneling must be enabled in both the SGSN service and in the Call-Control Profile. Otherwise a direct tunnel will never be established.
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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; <keyword> and <keyword. Refer to the SGSN Service Configuration Mode chapter in the 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 <map_name> context <map_context>
         ran-protocol iups-service <iups_svc_name> context <iups_context>
         sgtp-service <svc_name> context <name>
            accounting cdr-types [ mcdr | scdr ]
            accounting context <acct_context>
            cc profile <profile_number> interval <seconds>
            gs-service context <ctxt> service <gs_service_name>
            end
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:
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Example Configuration
configure
   context <context_name>
      gprs-service <gprs_service_name>
         accounting <ctxt>
         plmn id mcc <mcc_num> mnc <mnc_num>
         associate-service <service_type> <service_id> 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.
Step 1
[local]<hostname>(nse-ip-local)#
Step 2
[local]<hostname>(nse-ip-local-nsvl-<id>)#
Step 3
Step 4
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
Step 1
[local]<hostname>(nse-fr-peer-nsei-id)#
Step 2
[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.
Step 1
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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:
Step 1
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Step 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:
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:
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.
You can select transport layer protocol as TCP or UDP for Ga interface with gtpp transport-layer command. By default it is UDP.
Verifying GTPP Group Configuration
Step 1
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
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.
For command details, refer to the Card Configuration Mode Commands chapter and the Port Configuration Mode Commands chapter in the Cisco ASR 5000 Series Command Line Interface Reference.
Step 1
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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
 
 

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