Panasonic KX-NS500, Installation Manual

Page: 318 / 338

8.3.2 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-IPGW 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—Shelf Property—V-IPGW—
Gatekeeper Available" and "9.11.1 PBX
Configuration—[1-1] Configuration—Slot—Shelf Property—V-IPGW—GK Settings" in the PC Programming
Manual. After programming, the V-IPGW 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-IPGW card, consult a certified dealer.
8.3.3 Bandwidth Assessment
When using the IP telephones and V-IPGW 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)
*1
•
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
*1
/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.
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8.3.3 Bandwidth Assessment