8. The method of claim 7 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.
8. The method of claim 7 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. 9. The method of claim 8 wherein the plurality of GTT modes includes a called party GTT mode where the GTT lookup is performed based on called party parameters in the signaling message.