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Preliminary November 23, 1998
MultiVoice Gateway for the MAX— User’s Guide
Introducing MultiVoice Gateway concepts
MultiVoice applications
This architecture can also support PBX intraflow. The PBX can be configured to routes calls to
the alternative path when all trunks between PBXs are in use. PBX intraflow reduces the
number of inter-PBX trunks the company needs, while ensuring that users can make calls even
during busy periods.
PC-to-Phone calls
Figure 1-10 shows how to PC-to-Phone calls could be connected using either a virtual private
network (VPN) or an ISP’s PoP.
Figure 1-10. Virtual private network using PC telephony
The callers in San Francisco use their PCs to place calls to phone numbers in New York from
inside the VPN, utilizing the backbone IP network as the link to the destination MultiVoice
Gateway.
The callers in Dallas use their PCs to place calls to phone numbers in New York through a
local PoP provided by an ISP, utilizing the Internet connection as the link to the destination
MultiVoice Gateway.
Calls initiated from PCs connected to a network are processed as if the PC was one of the
MultiVoice Gateways. This requires that the PC be a fully H.323 compliant terminal. It must
be able to register and communicate with the Gatekeeper as if it were a MultiVoice Gateway. It
must also be able to communicate with the MultiVoice Gateway at the other end of the call.
H.323 compliant terminals
An H.323 compliant terminal is described in detail in the International Telecommunications
Union (ITU) Telephone Recommendation H.323. To work with Ascend’s MultiVoice for the
MAX, a PC must use a telephony application which supports:
•
Registration, Admission and Status (RAS) messaging with a Gatekeeper
•
The G.711 audio coder/decoder (required)
•
The G.729(a) and G.723.1 audio coder/decoders (optional).
!
Caution:
Not all third-party telephony software has full RAS messaging capability, or works
with a Gatekeeper. PictureTel’s LiveLAN, version 3.00, was successfully tested and proven
compatible with MultiVoice networks. Calls made from PCs using other applications may fail.
Local PSTN
San Francisco
New York
MultiVoice
Gateway
Gatekeeper
H.323
Compliant
Terminal
Dallas
IP network
IP Router
IP Router
H.323
Compliant
Terminal
ISP PoP
