Patent ID: 8527656

Claim:
A method, comprising: a client creating a list of a plurality of servers; the client determining a first sub-plurality of servers with which to register, wherein the first sub-plurality of servers comprises more than one but fewer than all servers of the plurality of servers; the client registering with the first sub-plurality of a plurality of servers; the client obtaining services from at least one server of the first sub-plurality of servers; in response to a first server of the first sub-plurality becoming unavailable to the client, the client determining a second sub-plurality of the plurality of servers with which to register; the client registering with the second sub-plurality of servers, wherein at least a second server is currently included in the first sub-plurality of servers, thereby adding the second server to the second sub-plurality of servers, wherein the client is in an active-standby configuration; the client, receiving an inbound call from the second server; in response to the client receiving the inbound call from the second server: the client responding to the second server with a SIP TRYING message; and sending a SIP REGISTRATION refresh to the first server; and in response to the first server being online, sending a SIP REDIRECT message to the second server.