Cisco Cisco ASR 5000
Serving GPRS Support Node (SGSN) Overview
▀ SGSN Core Functionality
▄ SGSN Administration Guide, StarOS Release 18
SS7 variants supported:
ITU-T (International Telecommunication Union - Telecommunications - Europe)
ANSI (American National Standards Institute - U.S.)
B-ICI (B-ISDN Inter-Carrier Interface)
China
TTC (Telecommunication Technology Committee - Japan)
NTT (Japan)
SS7 protocol stack components supported:
MTP2 (Message Transfer Part, Level 2)
MTP3 (Message Transfer Part, Level 3)
SCCP (Signaling Connection Control Part ) with BSSAP+ (Base Station System Application Part Plus)
and RANAP (Radio Access Network Application Part)
ISUP (ISDN User Part
TCAP (Transaction Capabilities Applications Part) and MAP (Mobile Application Part)
PDP Context Support
Support for subscriber primary and secondary Packet Data Protocol (PDP) contexts in compliance with 3GPP standards
ensure complete end-to-end GPRS connectivity.
ensure complete end-to-end GPRS connectivity.
The SGSN supports a total of 11 PDP contexts per subscriber. Of the 11 PDP context, all can be primaries, or 1 primary
and 10 secondaries or any combination of primary and secondary. Note that there must be at least one primary PDP
context in order for secondaries to establish.
and 10 secondaries or any combination of primary and secondary. Note that there must be at least one primary PDP
context in order for secondaries to establish.
PDP context processing supports the following types and functions:
Types: IPv4, IPv6, IPv4v6 (dual stack) and/or PPP
GTPP accounting support
PDP context timers
Quality of Service (QoS)
Mobility Management
The SGSN supports mobility management (MM) in compliance with applicable 3GPP standards and procedures to
deliver the full range of services to the mobile device. Some of the procedures are highlighted below:
deliver the full range of services to the mobile device. Some of the procedures are highlighted below:
GPRS Attach
The SGSN is designed to accommodate a very high rate of simultaneous attaches. The actual attach rate depends on the
latencies introduced by the network and scaling of peers. In order to optimize the entire signaling chain, the SGSN
eliminates or minimizes bottlenecks caused by large scale control signaling. For this purpose, the SGSN implements
features such as an in-memory data-VLR and SuperCharger. Both IMSI and P-TMSI based attaches are supported.
latencies introduced by the network and scaling of peers. In order to optimize the entire signaling chain, the SGSN
eliminates or minimizes bottlenecks caused by large scale control signaling. For this purpose, the SGSN implements
features such as an in-memory data-VLR and SuperCharger. Both IMSI and P-TMSI based attaches are supported.