3.1.5.3 Keeping a Session Context Alive by Using the PING Request Type

Since the Session Context will automatically expire on the server after a period of inactivity, the client MUST keep the Session Context alive. The client can do this by issuing a PING request type request, as specified in section 2.2.6. The client MUST pass all of the session context cookies that are returned from the server in the previous response. Additional cookies, such as the return sequence cookie, are also passed if available.

The client gets verification that the Session Context idle-time timer (section 3.1.2) was refreshed when it receives a successful PING response containing the X-ExpirationInfo header. The client SHOULD allow for network latency and issue a PING request type request at an interval that is less than what is specified in the X-ExpirationInfo header.