Abstract: Methods for use in operation with a signaling path between given entities are disclosed. One such method includes: deriving, from signaling messages between the given entities, a negotiated set of attributes of an expected media session between the given entities; inferring, from the signaling messages and from semantics of another protocol underlying a session initial protocol, an inferred set of one or more non-negotiated attributes of the expected media session; during an actual media session negotiated by the given entities, determining whether the negotiated set and the inferred set of one or more non-negotiated attributes correspond to given attributes of the actual media session; and taking an administratively-defined action if the negotiated set and the inferred set of one or more non-negotiated attributes do not correspond to given attributes of the actual media session.

Abstract: A media control system (MCS) enforces media control policies on systems that conform to the relevant protocol specifications (such as SIP and SDP), for example, by interpreting and potentially modifying or destroying the SDP offers embedded in the SIP signaling messages that traverse it. This enables the MCS to exercise control over SIP-associated media sessions without necessarily inserting itself into the media streams themselves. The MCS can enforce media control policies that are based either directly on information that is explicitly contained in SDP message bodies or on secondary information that can be derived from information that is contained in the SDP messages.