31. The computer program product of claim 25 wherein the plurality of GTT modes includes an advanced called party GTT mode in which the GTT lookup is performed based on at least one of called party parameters, calling party parameters, and message transfer part (MTP) parameters in the signaling message.
31. The computer program product of claim 25 wherein the plurality of GTT modes includes an advanced called party GTT mode in which the GTT lookup is performed based on at least one of called party parameters, calling party parameters, and message transfer part (MTP) parameters in the signaling message. 32. The computer program product of claim 31 wherein the plurality of GTT modes includes a calling party GTT mode where the GTT lookup is performed based on calling party parameters in the signaling message.