Abstract: An apparatus includes a transceiver to support a media flow involving a user equipment and an Internet Protocol (IP) Multimedia Subsystem (IMS) network that are connected via a media path that traverses a first realm associated with the user equipment, a second realm, and a third realm associated with the IMS network. In some cases, the apparatus includes a processor to establish a first context to perform interworking between the first realm and the second realm in response to an offer message from the user equipment. The processor later de-allocates the first context in response to receiving an answer message indicating that a second context performs interworking between the first realm and the third realm. In other cases, the processor bypasses allocation of a context to perform interworking between the second realm and the third realm in response to an indication that the media flow is anchored on an incoming side.

Abstract: A transcoder-free operation (TrFO) implementation is disclosed that provides backward-compatibility, or interworking between nodes supporting Iu UP version 1 and version 2. A media gateway (MGW) on the terminating side of a prospective call detects mismatching RFCI values between an originating and terminating side of a prospective call, such as may occur when an originating MGW supports Iu UP version 2 and a terminating Radio Network Controller (RNC) supports Iu UP version 1. The terminating MGW performs a mapping and translation function to convert RFCI values associated with Iu UP version 2 to those of version 1, or vice versa, so as to accommodate the terminating RNC supporting Iu UP version 1.

Abstract: The present invention provides a method for recovering a mismatch between a media gateway (MGW) and a media gateway controller (MGC). The MGC believes that a channel is idle and attempts to assign the channel in a bearer connection. The state information of the MGW indicates that the channel is busy. In response to a message indicating that the channel assignment failed from the MGW, the MGC sends a subtract message to the MGW to locate the termination and release that resource by returning the termination to an idle state. At this point the state of the channel has been resynchronized between the MGW and the MGC. The MGW then removes all endpoints associated with the context to release the resource from all contexts and bearer connections.