CISCO-EPC-GATEWAY-MIB
This MIB module manages the features and configuration for PDN Gateway(PGW) and Serving Gateway(SGW) in Evolved Packet Core(EPC) architecture. The PGW is the permanent IP point-of-attachment for access via the E-UTRAN. The PGW performs IP policy and charging enforcement on packet flows to and from mobile devices. The SGW is a local mobility anchor for E-UTRAN mobility, switching packets between the S5 interface and the GTP based S1-U interface for mobiles in connected mode. +------------------------------------------------+ | | | | | +=======+__________ | | | UTRAN | |S12 | | | +======+ | | | +======| | | | | +======| SGSN |___ | | | | +======+ || | | | GERAN | | S4|| | | +=======+ |(GTP-C|| | | S3| VO,V1|| | | | GTPU|| | | |VO,V1)|| | | +======+ || | | ____| MME |__ || | | | +======+ ||| | | S1-MME| S11 ||| | | | GTP-C ||| | | | (V0,V1,V2) ||| | |+====+ +========+ +======+ +======+ | +===+ || UE |-|E-Utran | | SGW | | PGW |-SGi-|PDN| || | |(EnodeB)| | | | | | | | |+====+ +========+ +======+ +======+ | +===+ | | | | GTP-C | | | | | |(vo,v1,v2)| | | | | |GTP-C | | | | | | (vo,v1) | | | | GTP v2-u | | | | | ------------ ----------- | | (S1-U) S5 | | | +------------------------------------------------+ This architecture supports the non-roaming and roaming architectures using GTP based protocol on the PGW and SGW with a number of functions. It support high number of subscribers with their associated control messages and data traffic. Each of this association forms an entry in PGW and SGW and is commonly know as bearers. The various features used by this architecture and their attributes are captured in this MIB: 1. Overload protection, handles congestion control, SGW and PGW represent congestion as a DFP metric considering the current CPU, memory usage and number of bearers open. On reaching the low congestion threshold, based on the ARP, high priority calls are accepted and those with a lower priority are rejected. Once the high threshold is reached all new calls are rejected. 2. Buffering agent, the SGW buffers the data packets in the downlink direction till the downlink path/peer information is ready. It buffers all packets coming from any gateway based on the default/configured values of the buffer size, discard period and number of packets. Packets will be buffered on a per bearer basis and retrieved in the order it was buffered using the handle given by the buffering agent initially. If the buffer is full then no more bearers will be accepted. Acronyms and terms: 3GPP 3rd Generation Partnership Project DFP Dynamic Feedback Protocol EDGE Enhanced Data rates for GSM Evolution EPC Evolved Packet Core E-UTRAN Evolved UTRAN GERAN GSM EDGE Radio Access Network GPRS General Packet Radio Service GSM Global System for Mobile communications GTP GPRS Tunneling Protocol PDN Public Data Network PGW PDN Gateway SAE System Architecture Evolution SGW Serving Gateway SP GW An integrated SGW and PGW Gateway UE User Equipment UMTS Universal Mobile Telecommunications System UTRAN UMTS Radio Access Network REFERENCE [1] 3GPP: Evolved GPRS Tunneling Protocol for Control Plane (GTPv2-C). 3GPP TS 29.274 V1.3.1. [2] 3GPP: GPRS enhancements for E-UTRAN access. 3GPP TS 23.401 V8.3.0. [3] 3GPP: Circuit Switched fallback in Evolved Packet System(EPS). 3GPP TS 23.272.