Methods and systems for processing a signaling message are disclosed. An exemplary method comprises: determining a first transcoding policy associated with an originator endpoint contained in a received first call offer; determining a second transcoding policy associated with an answerer endpoint contained in the first call offer; applying the first transcoding policy to a first offer codec set in the first call offer to produce a second call offer containing a second offer codec set; applying the second transcoding policy to the second codec set to produce a third call offer containing a third offer codec set; comparing a first answerer codec set in a received first answer and a second answerer codec set contained in the second call offer; and determining whether or not to perform transcoding based on a result of the comparison.