The following figure shows the interworking of the EPC with the different radio access technologies.
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System Management Cards (SMCs): Provides full system control and management of all cards within the ASR 5000 platform. Up to two SMC can be installed; one active, one redundant.
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Packet Services Cards (PSCs): Within the ASR 5000 platform, PSCs provide high-speed, multi-threaded PDP context processing capabilities for 4G S-GW services. Up to 14 PSCs can be installed, allowing for multiple active and/or redundant cards.
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Switch Processor Input/Outputs (SPIOs): Installed in the upper-rear chassis slots directly behind the SMCs, SPIOs provide connectivity for local and remote management, central office (CO) alarms. Up to two SPIOs can be installed; one active, one redundant.
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Line Cards: Installed directly behind PSCs, these cards provide the physical interfaces to elements in the E-UTRAN EPC data network. Up to 26 line cards can be installed for a fully loaded system with 13 active PSCs, 13 in the upper-rear slots and 13 in the lower-rear slots for redundancy. Redundant PSCs do not require line cards. Ethernet 10/100, Ethernet 1000 or 10 Gigabit Ethernet line cards are available for IP connections to other network elements.
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Redundancy Crossbar Cards (RCCs): Installed in the lower-rear chassis slots directly behind the SPCs/SMCs, RCCs utilize 5 Gbps serial links to ensure connectivity between Ethernet Ethernet 1000 line cards and every PSC in the system for redundancy. Two RCCs can be installed to provide redundancy for all line cards and PSCs.
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Important: Additional information pertaining to each of the application and line cards required to support LTE-SAE services is located in the Hardware Platform Overview chapter of the Cisco ASR 5000 Series Product Overview Guide.
Important: To configure the basic service and functionality on the system for the S-GW service, refer to the configuration examples provided in the Serving Gateway Administration Guide.|
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System: Provides system-level statistics
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Card: Provides card-level statistics
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Port: Provides port-level statistics
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MAG: Provides MAG service statistics
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S-GW: Provides S-GW node-level service statistics
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IP Pool: Provides IP pool statistics
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APN: Provides Access Point Name statistics
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Important: For more information on bulk statistic configuration, refer to the Configuring and Maintaining Bulk Statistics chapter in the System Administration Guide.|
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TAI-ID: Tracking Area Identity
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MCC: MNC: Mobile Country Code, Mobile Network Code
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TAC: Tracking Area Code
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MCC: MNC: Mobile Country Code, Mobile Network Code
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CSG-ID: Closed Subscriber Group Identifier
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Access Mode: CSG access mode received from the sourc eNodeB or RNC
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Congestion Condition Thresholds: Thresholds dictate the conditions for which congestion control is enabled and establish limits for defining the state of the system (congested or clear). These thresholds function in a way similar to operational thresholds that are configured for the system as described in the Thresholding Configuration Guide. The primary difference is that when congestion thresholds are reached, a service congestion policy and an SNMP trap, starCongestion, are generated.
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Port Utilization Thresholds: If you set a port utilization threshold, when the average utilization of all ports in the system reaches the specified threshold, congestion control is enabled.
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Port-specific Thresholds: If you set port-specific thresholds, when any individual port-specific threshold is reached, congestion control is enabled system-wide.
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Service Congestion Policies: Congestion policies are configurable for each service. These policies dictate how services respond when the system detects that a congestion condition threshold has been crossed.
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Important: For more information on congestion control, refer to the Congestion Control appendix in the System Administration Guide.
Important: The S-GW supports interface-based ACLs only. For more information on IP access control lists, refer to the IP Access Control Lists appendix in the System Administration Guide.|
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Important: P-GW management functionality is enabled by default for console-based access. For GUI-based management support, refer to the Web Element Manager section in this chapter.
Important: For more information on command line interface based management, refer to the Command Line Interface Reference and P-GW Administration Guide.QoS Class Identifier (QCI): An operator provisioned value that controls bearer level packet forwarding treatments (for example, scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc). Cisco EPC gateways also support the ability to map the QCI values to DiffServ codepoints in the outer GTP tunnel header of the S5/S8 connection. Additionally, the platform also provides configurable parameters to copy the DSCP marking from the encapsulated payload to the outer GTP tunnel header.
Guaranteed Bit Rate (GBR): A GBR bearer is associated with a dedicated EPS bearer and provides a guaranteed minimum transmission rate in order to offer constant bit rate services for applications such as interactive voice that require deterministic low delay service treatment.
Maximum Bit Rate (MBR): The MBR attribute provides a configurable burst rate that limits the bit rate that can be expected to be provided by a GBR bearer (e.g. excess traffic may get discarded by a rate shaping function). The MBR may be greater than or equal to the GBR for a given dedicated EPS bearer.
Aggregate Maximum Bit Rate (AMBR): AMBR denotes a bit rate of traffic for a group of bearers destined for a particular PDN. The Aggregate Maximum Bit Rate is typically assigned to a group of Best Effort service data flows over the Default EPS bearer. That is, each of those EPS bearers could potentially utilize the entire AMBR, e.g. when the other EPS bearers do not carry any traffic. The AMBR limits the aggregate bit rate that can be expected to be provided by the EPS bearers sharing the AMBR (e.g. excess traffic may get discarded by a rate shaping function). AMBR applies to all Non-GBR bearers belonging to the same PDN connection. GBR bearers are outside the scope of AMBR.
Policing and Shaping: The Cisco P-GW offers a variety of traffic conditioning and bandwidth management capabilities. These tools enable usage controls to be applied on a per-subscriber, per-EPS bearer or per-PDN/APN basis. It is also possible to apply bandwidth controls on a per-APN AMBR capacity. These applications provide the ability to inspect and maintain state for user sessions or Service Data Flows (SDF's) within them using shallow L3/L4 analysis or high touch deep packet inspection at L7. Metering of out-of-profile flows or sessions can result in packet discards or reducing the DSCP marking to Best Effort priority. When traffic shaping is enabled the P-GW enqueues the non-conforming session to the provisioned memory limit for the user session. When the allocated memory is exhausted, the inbound/outbound traffic for the user can be transmitted or policed in accordance with operator provisioned policy.
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Bearer management function: This functionality is responsible for bearer management; setting up, modifying and releasing EPS bearers, which are triggered by the MME. The release of EPS bearers may be triggered by the P-GW or HSS as well. The messages include Create Session request, Create Bearer request, Create bearer response etc. Additionally GTP tunnel management messages may be sent for any of the following reasons:
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Path management function: This functionality is responsible for managing the path between the tunnel endpoints. It includes messages like ECHO request, ECHO response and version not supported indication.
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Mobility management functions: This functionality consists of messages that are exchanged between GTP end points to manage UE mobility. Messages such as Forward Relocation request/response are sent between end points. These messages are not sent on the S11 interface.
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Alert: A value is monitored and an alert condition occurs when the value reaches or exceeds the configured high threshold within the specified polling interval. The alert is generated then generated and/or sent at the end of the polling interval.
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Alarm: Both high and low threshold are defined for a value. An alarm condition occurs when the value reaches or exceeds the configured high threshold within the specified polling interval. The alert is generated then generated and/or sent at the end of the polling interval.
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SNMP traps: SNMP traps have been created that indicate the condition (high threshold crossing and clear) of each of the monitored values.
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Logs: The system provides a facility called threshold for which active and event logs can be generated. As with other system facilities, logs are generated Log messages pertaining to the condition of a monitored value are generated with a severity level of WARNING.
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Alarm System: High threshold alarms generated within the specified polling interval are considered outstanding until a the condition no longer exists or a condition clear alarm is generated. Outstanding alarms are reported to the system's alarm subsystem and are viewable through the Alarm Management menu in the Web Element Manager.
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Important: For more information on threshold crossing alert configuration, refer to the Thresholding Configuration Guide.
Important: For more information on WEM support, refer to the WEM Installation and Administration Guide.
For more information on Direct Tunnel configuration, refer to the Direct Tunnel Configuration appendix in this guide.
Important: For more information on inter-chassis session recovery support, refer to the Interchassis Session Recovery appendix in System Administration Guide.
Important: You must purchase an IPSec license to enable IPSec. For more information on IPSec support, refer to the IP Security appendix in this guide.
Important: For more information on VLAN support, refer to the VLANs appendix in the System Administration Guide.
Important: For more information on session recovery support, refer to the Session Recovery appendix in the System Administration Guide.
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