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.|