GTP-C message flows between different interface to setup the signalling connection. The interfaces are S11, S5, S8 and S4.
There are two type of GTP-C messages are there.
1. Path management messages
2. Tunnel management messages.
1. Path Management Messages
ECHO request/response will be used to ping destination GTP end point as well handle the restart procedure of a GTP endpoint.
Please refer ECHO message handling in GTP-C
2. Tunnel Management Messages
Different GTP-C messages are used to manage a Tunnel. The GTP-C messages are Create Session Request/Response, Create Bearer Request/Response, Modify Bearer Request/Response, Update Bearer Request/Response, Delete Session Request/Response, Delete Bearer Request/Response etc.