8.2.2 Gatekeeper
The following are the general functions of a gatekeeper:
•
Dialled number-to-IP address translation
•
Authentication
•
Bandwidth control
The gatekeeper provides these network management functions to registered clients. To register with the
gatekeeper, you need to configure the V-IPGW4 card to use the gatekeeper and programme the GK Settings
table through system programming. For details, refer to "9.11 PBX Configuration—[1-1]
Configuration—Slot—V-IPGW—Shelf Property—
Gatekeeper Available" and "9.11.1 PBX
Configuration—[1-1] Configuration—Slot—V-IPGW—Shelf Property—GK Settings" in the PC Programming
Manual. After programming, the V-IPGW4 card attempts to register with the gatekeeper using registration
information such as the IP address of the mother board, and destination telephone numbers specified in the
GK Settings table.
Note
•
For more information about gatekeeper functions, consult the documentation of the gatekeeper.
•
When using a gatekeeper, make sure to choose a compatible model. For more information about
gatekeeper compatibility with the V-IPGW4 card, consult a certified dealer.
8.2.3 Bandwidth Assessment
When using the IP telephones and V-IPGW4 card, you must ensure that the IP network in use has enough
bandwidth to support VoIP communications. If the amount of bandwidth required for VoIP communications is
more than the network can accommodate, speech quality will be compromised. In addition, there may be an
adverse effect on the performance of other applications (e.g., e-mail or Web applications) that use the same
network. Therefore, care must be taken when assessing bandwidth requirements.
Inform your network administrator of the required bandwidth, and make sure that the network can support VoIP
communications even under conditions of maximum network traffic.
Bandwidth Assessment for IP Extension Card
Required Bandwidth per IP Telephone for a Call
The required bandwidth depends on what combination of codecs and packet sending intervals is used. Keep
in mind the following points about the type of codecs and packet sending intervals, in terms of speech quality:
•
The speech quality of the codecs varies as follows: (High) G.722, G.711, G.729A (Low)
•
The shorter the packet sending interval, the higher the speech quality.
•
The higher the speech quality the IP telephones provide, the more bandwidth the IP telephones require.
*1
When the preferred codec of each party differs, the call will be established using the lower codec. For example, if the caller prefers
G.711 while the called party prefers G.729A, the call will be established using G.729A.
Codec
Packet Sending Interval
20 ms
30 ms
40 ms
60 ms
G.722
/G.711
87.2 kbps
79.5 kbps
—
—
G.729A
31.2 kbps
23.5 kbps
19.6 kbps
15.7 kbps
*1
G.722 is only available for calls between KX-NT300 series IP-PTs, KX-NT500 series IP-PTs, and some SIP phones that support this
codec during peer-to-peer communication. For details, refer to "5.2.3 Peer-to-Peer (P2P) Connection" in the Feature Guide.
280
Installation Manual
8.2.3 Bandwidth Assessment
Summary of Contents for KX-NS300
Page 92: ...4 Hook the main unit on the screw heads 92 Installation Manual 4 2 10 Wall Mounting...
Page 150: ...150 Installation Manual 4 13 Starting the KX NS300...
Page 248: ...248 Installation Manual 5 11 Automatic Configuration of Mailboxes...
Page 252: ...252 Installation Manual 6 1 Methods of Stacking Expansion Units...
Page 294: ...294 Installation Manual 8 5 Port Security...
Page 298: ...298 Installation Manual 9 2 System Prompt Languages...
Page 299: ......
