| abstract |
A protocol identifier, such as, a GTP version identifier, is automatically cached in association with device contact information. Setup latency is reduced for subsequent connections. For instance, the cache indicates that a GGSN only supports GTPV 0 . An SGSN attempts to create a PDP context with the GGSN using GTPV 0 without first trying GTPV 1 . If the cache does not include a version identifier for an APN IP address, the SGSN tries to create a context with a first version (e.g., GTPV 1 ) and, if necessary, a second version (e.g., GTPV 0 ). An identifier associated with the successful protocol is stored in the cache in association with the contact information (e.g., APN or APN IP address). Freshness of cached information is assured. For example, when all tunnels associated with an APN IP address are torn down, a flush timer is started. If the timer expires, the cache entry is removed. |