Cisco Cisco ASR 5000
SGSN Pooling
Feature Description ▀
SGSN Administration Guide, StarOS Release 18 ▄
Figure 93. A basic pool structure
Multiple SGSNs form a single logical entity called SGSN pool.
SGSN pools service areas larger than stand-alone SGSN service areas.
This set up is compatible with non-pool aware nodes and is transparent to the end-user.
Benefits of SGSN Pooling
1. Increased Availability: If one SGSN fails, another SGSN from the pool can substitute it. Any node can be taken out of a
pool during maintenance.
2. Increased Scalability: More number of SGSN nodes can be added to the pool.
3. Reduced Signalling: Number of inter-SGSN routing area updates is reduced.
3. Reduced Signalling: Number of inter-SGSN routing area updates is reduced.
Pooling Requirements
Listed below are the requirements to support pooling:
1. The SGSN should support configuration of NRI and use that NRI in all the PTMSI issued.
2. If the SGSN is configured as a default SGSN, it should relay SGSN Context Request / Identification request received
2. If the SGSN is configured as a default SGSN, it should relay SGSN Context Request / Identification request received
from peer SGSN (outside of pool) to SGSN (in pool) anchoring that subscriber anchoring SGSN in pool.