Multi-Tech Systems MVP120 - Manual (Page 9)

9
Chapter 1 - Introduction to the MultiVOIP
Multi-Tech Systems, Inc. MultiVOIP User Guide
The H.323 Gatekeeper acts as the central point for all calls within its zone and provides call
control services to registered endpoints. If you choose the proprietary phone book, you
establish a master-slave relationship where the master MultiVOIP maintains the phone
directory and downloads the directory to each slave unit.
The Gatekeeper/Proprietary Phone Book selection is chosen from the Phone Directory
Database dialog box. Before you choose how the data base is going to be used, here are a
couple of things to keep in mind:
1. If a Gatekeeper is employed in the network, you need to choose the Gatekeeper option.
You can not mix the Proprietary Phone Book with the Gatekeeper. If you choose the
Gatekeeper option you can communicate with other third party endpoints that support
H.323 (such as Microsoft Netmeeting).
2. If you choose the Proprietary Phone Book, you establish a master-slave relationship in
which the master MultiVOIP maintains the phone directory database. All of the phone
numbers are listed in the data base so that if you want to communicate with someone in
your VOIP network, you can see the phone number in your data base. Everytime you
bring up your MultiVOIP the current phone directory is downloaded to your MultiVOIP.
Note: You can still call Netmeeting using the proprietary phone book.
The Gatekeeper
The GateKeeper is a separate application that can operate on a network pc and provides all
the controls needed to create, control, and manage an H.323 network zone. The H.323
network zone is all the endpoints (terminals and gateways (MultiVOIPs)) that are registered
with the gatekeeper. The gatekeeper function is address translation from LAN aliases for
terminals and gateways to IP addresses as defined in the RAS (Registration/Admission/
Status) specification. The RAS Protocol defines the communication with a gatekeeper and
support for RTP/RTCP for sequencing audio packets. The H.323 Gatekeeper also provides
call-authorization for both accepting and placing calls in its zone, and certain monitoring
features such as call permissioning and address resolution.
If you choose the Gatekeeper option, initially you need to communicate with the administrator
of the Gatekeeper to register your MultiVOIP. The information you need from the Gatekeeper
administrator is the IP address of the Gatekeeper and its port number. Then you need to
establish your alias address which includes phone number, channel number, H323 ID which
can be a numeric or an alphanumeric value, and your MultiVOIP LAN IP address. The port
number is 1720, but if the Gatekeeper uses a different port number, you have to ensure that