3Com Nbx 100 And Ss3 Nbx Administration Guide

Installing ConneXtions421
Installing 
ConneXtionsTo install the NBX ConneXtions H.323 Gateway:
1Insert the Resource Pack CD into the PC. Click NBX Applications, and 
then click NBX ConneXtions, and then
 click OK.
If the program does not start automatically, click the Windows Start 
menu, and then Run. Type D:autorun, substituting the letter of your 
CD-ROM drive for D, and click OK. 
2Respond to these initial InstallShield dialog boxes:
aIn the Welcome dialog, click Next.
bIn the License Agreement...

422APPENDIX A: CONNEXTIONS H.323 GATEWAY
8Only one Gateway? - Click Ye s if the NBX system has only one H.323 
gateway system.
CAUTION: Multiple gateways must have unique configurations. Multiple 
gateways need a distinguishing “Gateway Number”. Assign the first 
installed gateway to number 0; the second to number 1; and so on. 
3Com recommends that licenses be allocated equally when using 
multiple gateways.
9Enter the Call Processor MAC Address. To find it, log on as an 
administrator in the NBX NetSet...

Installing ConneXtions423
15Do you want to use alternate Gatekeepers? If you select Ye s, the chosen 
gatekeeper maintains a list of alternate gatekeepers to be used if the 
preferred gatekeeper does not respond.
If you choose to use alternate gatekeepers and have also selected to 
autodiscover new gatekeepers if ConneXtions cannot contact the 
preferred gatekeeper, ConneXtions first tries to use alternate gatekeepers 
from the list (in priority order); if this fails, it then tries to autodiscover a 
new...

424APPENDIX A: CONNEXTIONS H.323 GATEWAY
Overview of H.323The H.323 standard provides a foundation for audio, video, and data 
communications across IP-based networks, including the Internet. By 
complying with H.323, multimedia products and applications from 
different vendors can interoperate, allowing users to communicate 
without concern for compatibility.
An NBX ConneXtions H.323 Gateway provides connections similar to 
tie lines between existing NBX systems across an IP network. However, it 
can...

Overview of H.323425
connection alive until one of the parties ends the connection. A call 
tear-down signal indicates to the network, and to the other party, when a 
call ends. On standard telephone networks, the telephone company uses 
this signal to determine when to start and stop charging for long distance 
calls, but long distance charges do not normally apply to H.323 calls. 
Other reasons for call setup and tear-down signals are to indicate when 
an IP network can release bandwidth to support...

426APPENDIX A: CONNEXTIONS H.323 GATEWAY
(G.711 and G.723), H.323 gateways negotiate the type of compression 
they use during each call setup. Negotiation ensures that the compression 
on the transmit side matches the decompression processing on the 
receiving side. With the frame and packet overhead, each G.723 channel 
needs about 19.2 Kbps of the available bandwidth.
Standard ExtensionsConneXtions routes incoming H.323 calls to one designated extension, 
usually the Auto Attendant. Callers can dial...

The H.323 Connection427
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...

428APPENDIX A: CONNEXTIONS H.323 GATEWAY
Connection 
ConsiderationsAs soon as an end-to-end connection has been set up, all three networks 
(local LAN, WAN, and remote LAN) are ready to pass voice packets. The 
NBX Business and Basic Telephones use their DSP to convert spoken 
words into digital voice packets. The voice packets are transferred across 
the Ethernet to the local H.323 gateway. The gateway strips off the 
Ethernet frames, compresses the voice, and encapsulates it within UDP 
packets which...

Connection Considerations429
Because so many devices share the same physical media on the Internet 
and on the local network, there is always the possibility of incomplete or 
degraded connections that arise from network congestion, device 
configuration, or addressing problems.
Bridges, switches, routers, and firewalls can help to manage network 
congestion, conversions, and security. Configuration problems with of 
any of these devices can cause connection difficulties.
Bridges and switches are used to...

430APPENDIX A: CONNEXTIONS H.323 GATEWAY
Bandwidth 
Bandwidth is the capacity to carry information. By using H.323, the same 
bandwidth that supports one uncompressed G.711 voice connection can, 
instead, support several compressed G.723 conversations with little 
noticeable difference in quality.
Networks differ in the age of their equipment and in the quality of their 
service. Traffic can form a bottleneck if network loads force a wide area 
service provider to route traffic through old equipment....