The RAS channel is an unreliable channel which is used to carry messages used in the gatekeeper discovery and endpoint registration processes which associate an endpoint's alias address with its call signalling channel transport address. H.225.0 recommends time-outs and retry counts for various messages as the the RAS messages are transmitted on an unreliable channel.[para] Once an endpoint or gatekeeper cannot respond to a request within the specified timeout, may use the Request in Progress (RIP) message to indicate that it is still dealing out the request. An endpoint or gatekeeper receiving the RIP resets its timeout timer and retry counter.