3Com NBX 100 Administrator's Manual - page 416
416
A
PPENDIX
D: C
ONNE
X
TIONS
H.323 G
ATEWAY
Personal Computers
Microsoft NetMeeting software supports H.323 voice connections over
the Internet. The personal computer must be equipped with Internet
access, a sound system, and a microphone.
The current version of Microsoft NetMeeting (3.01) cannot conveniently
place calls through the Auto Attendant because it has no way of entering
extension digits after it reaches an IP address (the Auto Attendant). This is
a temporary limitation that usually disappears when those programs
upgrade to H.323 version 2. Version 2 requires that compliant devices
support out-of-band DTMF (touch-tone) signaling.
If you choose ConneXtions as the gateway under the Advanced Calling
options, and if you configure NetMeeting to “speed-dial” the IP address
and extension, Microsoft NetMeeting can place calls to an extension.
POTS Adapters
You can purchase circuit boards that plug into a personal computer and
adapt an analog telephone (POTS) for use with an H.323 connection.
H.323 Gatekeepers
The gatekeeper is an H.323 entity on the network that provides address
translation and controls access to the network for H.323 terminals,
Gateways, and MCUs. The gatekeeper also provides services to the
terminals, Gateways, and MCUs, such as managing bandwidth and
locating Gateways.
The H.323
Connection
H.323 calls between local and remote NBX Business and Basic Telephones
are transparent to users, except for the IP dial plan. The Call Processor
sets up the local end of the H.323 call as though it were setting up a call
through a line card. However, this connection actually goes to a network
interface card (NIC) in a dedicated Windows 2000 or Windows NT system
that is running the ConneXtions software.
The Call Processor requests an H.323 port in the ConneXtions software
by sending a frame, with a simulated Ethernet address, that contains a
requested IP address. The ConneXtions gateway uses this address to
request a level three connection between the local router and the remote
router associated with another PBX or NBX system.