I am trying a low cost uniform dial plan for over 10 offices with all G3 variations. We looked into VOIP, too costly and too new. We also looked into TIE lines, which are out of the question. Currently we use AMIS and my peers are wondering if any way possible to dial an access code to a specific trunk group and have the PBX insert an area code+exchange+then the 4 digit extension. Could we also transfer calls to other offices this way? Basically they want to fool the user that if they dial 5 digits the PBX will route to one of our other offices by inserting the appropriate digits. I believe that the DCS does the signaling and is needed to transfer a call from one location to another. Is this true. So I will need DCS on in every PBX and UDP if we go the AVAYA route. Otherwise, VOIP is jittery with IP trunks and not a viable soulution right now. Does or has anyone implemented a UDP without using the DCS or RTU from Avaya???