The present invention provides a redundancy mechanism for packet-based communication environments without requiring localized redundancy of session control entities. These session control entities are generally referred to as service nodes, which may act as proxies on behalf of the communication terminals being served. Instead of having a dedicated backup service node, other active service nodes, which primarily serve different groups of communication terminals, are configured to provide backup support when another service node fails. In operation, a communication terminal will periodically attempt to communicate with its primary service node. When the communication terminal detects that the attempts to communicate with the service node are unsuccessful, the communication terminal will attempt to register with a selected alternate service node, the alternate service node being a currently active service node primarily supporting another group of communication terminals. The alternate service node can then accept and support the communication terminal.