3.1.2.1 Client Refresh Timer
The client refresh timer is only used when the resolver client has registered endpoint information with the resolver service and does not require that information to be deleted.
This timer is used to determine when to call Refresh. The client MUST ensure that the Refresh operation is called before the time indicated by the RegistrationLifetime element has elapsed. This value is received as part of the RegisterResponse message in response to the initial Register request or any subsequent Update request.
Note that the exact interval used for the timer MAY vary to take into account the network latency between the resolver client and server.<1>