Self-forming VoIP network

A method of maintaining VoIP capabilities within a network comprising:

• forming a cluster of two or more initially isolated network nodes
• establishing communications between two or more client devices by way of the initially isolated network nodes, wherein in a first configuration, at least two of said initially isolated network nodes are in communication with each other but not in communication with an external SIP server, and wherein each of said at least two initially isolated network nodes supports VoIP communications based on a local SIP registry contained in each of the said nodes according to the method of:
• communicating with at least one other initially isolated node to exchange SIP registry information;
• updating the local SIP registry in said node as new information is acquired;
• sending and receiving VoIP packets from a sender isolated node to one or more recipient isolated nodes based on said local SIP registry functionality when a client device in communication with the sender node establishes communication with a client device in communication with the recipient node.