Identification Request/Response

GTP-C

Sent by the new SGSN to the old SGSN to request the IMSI for a MS when a GPRS Attach is done with a P-TMSI and the MS has changed SGSNs since the GPRS Detach was done.

SGSN context Request/ Response/ Acknowledge

GTP-C

Sent by the new SGSN to the old SGSN to request the MM and PDP Contexts for the MS.

Forward Relocation Request/ Response/ Complete/ Complete Acknowledge

GTP-C

Indicates mobile activation/deactivation within a Routing Area. This prevents paging of a mobile that is not active (visited VLR rejects calls from the HLR or applies Call Forwarding). Note that the mobile station does not maintain an attach/detach state.

SRNS contexts contain for each concerned RAB the sequence numbers of the GTP-PDUs next to be transmitted in uplink and downlink directions.

Relocation Cancel Request/ Response

GTP-C

Send to cancel the relocation of a connection.

Forward SRNS Context/ Context Acknowledge

GTP-C

This procedure may be used to trigger the transfer of SRNS contexts from RNC to CN (PS domain) in case of inter system forward handover.

RAN Information Relay

GTP-C

Forward the Routing Area Network (RAN) information.

A Routing Area (RA) is a subset of a GSM Location Area (LA). A RA is served by only one SGSN. Ensures that regular radio contact is maintained by the mobile