Method and system of transferring a message in a session initiation protocol based communications network

1. A method of transferring a first message and a second message, in a Session Initiation Protocol (SIP) based communications network, from a first node to a third node via a plurality of intermediate nodes, wherein the intermediate nodes are a user-to-network proxy entity, a registrar, or a service node, the method comprising:

storing, in a repository associated with the first node, a group identifier associated with a plurality of intermediate nodes; and

within a single session or within a single transaction of a session:

deriving, by the first node and based on the group identifier, a network address corresponding to a first intermediate node of the plurality of intermediate nodes;

transmitting, by the first node, the first message to the third node via the first intermediate node;

synchronizing among the plurality of intermediate nodes data relating to at least one of the first node and the third node;

deriving, by the first node and based on the group identifier, a network address corresponding to a second intermediate node of the plurality of intermediate nodes; and

transmitting, by the first node, the second message to the third node via the second intermediate node.

2. The method of claim 1 the deriving comprises performing a Domain Name Server (DNS) query on the basis of the group identifier.

3. The method of claim 1 wherein the first message comprises the group identifier; the method further comprising:

deriving, by the third node and based on the group identifier, a network address corresponding to one intermediate node of the plurality of intermediate nodes; and

transmitting, in response to receiving the first message, a response from the third node to the first node via the one intermediate node derived by the third node.

4. A Session Initiation Protocol (SIP) based communications network, comprising:

a first node;

a plurality of intermediate nodes;

a third node;

wherein the first node has a repository associated therewith, the repository comprising a group identifier associated with a plurality of intermediate nodes;

wherein the first node is configured to derive, based on the group identifier, a network address corresponding to a first intermediate node of the plurality of intermediate nodes for a first message of a SIP session or transaction;

wherein the first node is further configured to derive, based on the group identifier, a network address corresponding to a second intermediate node of the plurality of intermediate nodes for a second message of the SIP session or transaction;

wherein the first intermediate node is configured to synchronize data relating to at least one of the first node and the third node among the plurality of intermediate nodes; and

wherein the network is configured to transmit the first message from the first node to the third node via the first intermediate node and

to transmit the second message from the first node to the third node via the second intermediate node.

5. A network node for transmitting a first message and a second message to a recipient node via an intermediate node in a Session Initiation Protocol (SIP) based communications network, within a single SIP session or a single transaction within a SIP session; the network comprising:

a repository containing a group identifier associated with a plurality of intermediate nodes; and

wherein the network node is configured to:

derive, based on the group identifier, a network address corresponding to one intermediate node of the plurality of intermediate nodes;

transmit the first message to the recipient node via the one intermediate node derived by the network node;

synchronize, among the plurality of intermediate nodes, data relating to at least one of the network node and the recipient node;

derive, based on the group identifier, a network address corresponding to another intermediate node of the plurality of intermediate nodes; and

transmit the second message to the recipient node via the other intermediate node derived by the network node.

6. The network node of claim 5 wherein the network node is a User Agent or Proxy Call Session Control Function entity.