Patent ID: 8374587

Claim:
A method of modifying a call setup message for a call from a first terminal to a second terminal, the call setup message being sent from the first terminal to a negotiating network node via an intermediate node which handles signaling or traffic associated with the call, wherein the negotiating network node is responsible for negotiating call setup requirements for the call to the second terminal, the method comprising the steps of: intercepting the call setup message at the intermediate node; determining by the intermediate node, that a current network condition causes a resource restriction in the intermediate node that limits which codecs the intermediate node can use to handle signaling or traffic associated with the call; identifying by the intermediate node, one or more codec preferences or capabilities associated with the intermediate node that can be used by the intermediate node to handle signaling or traffic associated with the call while meeting the resource restriction caused by the current network condition; modifying by the intermediate node, the call setup message based on information relating to the identified codec preferences or capabilities; and sending the modified call setup message to the negotiating network node, so that the negotiating network node can effect negotiations based on the modified call setup message; wherein the call setup message is modified based on one or more of: adding an appendix to the call setup message including said one or more codec preferences or capabilities; deleting a codec preference or capability of the first terminal in the call setup message and substituting the one or more codec preferences or capabilities of the intermediate node; adding content in the call setup message in accordance with said one or more codec preferences or capabilities; ordering content in the call setup message in accordance with said one or more codec preferences or capabilities; and inserting a separator in the call setup message to indicate which content in the message is in accordance with said one or more codec preferences or capabilities.