1. A method comprising: forwarding a first request from a first user equipment to a second user equipment; forwarding a first response containing a session description protocol offer from the second user equipment to the first user equipment; receiving a second request from the first user equipment containing a session description protocol answer; determining that the session description protocol answer contains a parameter in breach of a local policy; and returning a second response indicating that the session description protocol answer is not acceptable, the second response containing a local policy allowed session description protocol payload.