Path management messages
Path management is used by one GSN to detect if another GSN is alive, or if it has restarted after a failure.
The path management procedure checks if a given GSN is alive or has been restarted after a failure. In case of SGSN restart, all MM and PDP contexts are deleted in the SGSN, since the associated data is stored in a volatile memory. In the case of GGSN restart, all PDP contexts are deleted in the GGSN.
| Message Type | Used by | Description |
|---|---|---|
|
Echo Request (1) Echo Response (2) |
GTP-C, GTP-U, GTP’ | Echo Request is sent on a path to another GSN to determine if the other node is alive. Echo Response is the reply. |
| Version Not Supported (3) | GTP-C, GTP-U, GTP’ | There are multiple versions of GTP. Both devices communicating must use the same version of GTP, or this message will be the response. |
| Supported Extension Headers Notification (31) | Extensions are optional parts that a device can choose to support or not. If a device includes these extensions, it must include headers for the extensions to sure ensure proper formatting. |