SGSN roaming in GGSN pooling scenarios

This feature allows the General Packet Radio Service (GPRS) tunneling protocol (GTP) to support different Gateway GPRS Support Node (GGSN) IP addresses when creating tunnels. There are two pooling scenarios for this feature: Scenario 1: GGSN uses a response packets source IP address different from the request packets destination IP address to send a response message to the Serving GPRS Support Node (SGSN). Scenario 2: SGSN or GGSN uses a response packets source IP address different from the payload GSN IP address for the GTP control (GTP-C) and GTP user plane (GTP-U) tunnel creation procedures.