A1 VoIP Requirements
46
Getting Started
A1
VoIP Requirements
A1.1
Bandwidth Assessment
When using the VoIP Gateway 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 larger than what the network can accommodate, speech quality will be
compromised. In addition, there may be some adverse effect on the performance of other applications
(e.g., email 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 Calculation
Provided below is the formula to find out the amount of bandwidth required for VoIP communications:
Required bandwidth for one VoIP channel is shown in the tables below (for more details, refer to "2.2.3
Voice Communication Parameters" in the VoIP Gateway Card Programming Guide).
Required Bandwidth for One VoIP Channel
The required bandwidth depends on what combination of CODEC and packet sending interval is
used. Keep in mind the following points about the type of CODEC and packet sending interval, in
terms of the speech quality:
•
The speech quality of the CODECs varies as follows: (High) G.711, G.729A, G.723.1 (Low)
•
The shorter the packet sending interval, the higher the speech quality.
•
The higher the speech quality the VoIP Gateway Card provides, the more bandwidth the
card requires.
Via LAN
Required Bandwidth
= (No. of Fax Machines × Required Bandwidth for the G.711 CODEC) +
[(16 - No. of Fax Machines) × Required Bandwidth for Voice Communication]
CODEC
Packet Sending Interval
20 ms
30 ms
40 ms
60 ms
90 ms
G.711
87.2 kbps
79.5 kbps
75.6 kbps
71.7 kbps
—
G.729A
31.2 kbps
23.5 kbps
19.6 kbps
15.7 kbps
—
G.723.1 5.3 kbps
—
20.8 kbps
—
13.1 kbps
10.5 kbps
G.723.1 6.3 kbps
—
21.9 kbps
—
14.1 kbps
11.6 kbps
Содержание KX-TDA0490
Страница 4: ...4 Getting Started ...
Страница 20: ...2 2 Cable Connection 20 Getting Started ...
Страница 45: ...Getting Started 45 Appendix A Guidance for VoIP Installation ...
Страница 55: ...Getting Started 55 Appendix B Alternative Numbering Plan Example ...
Страница 63: ...Getting Started 63 Appendix C Initialisation of the VoIP Gateway Card ...
Страница 66: ...C1 Initialising the VoIP Gateway Card 66 Getting Started ...
Страница 67: ...Getting Started 67 Appendix D Using the KX TDA0490 and KX TDA0480 in One Network ...
Страница 69: ...D1 Considerations in Installation Getting Started 69 ...
Страница 76: ...1 1 Starting the IP GW16 Maintenance Utility 6 Programming Guide ...
Страница 125: ...2 5 Others Programming Guide 55 2 5 2 Log Out 1 Click LOGOUT in the main menu 2 Click OK to log out ...
Страница 126: ...2 5 Others 56 Programming Guide ...
Страница 138: ...3 4 Others 68 Programming Guide 3 4 2 Log Out 1 Click LOGOUT in the main menu 2 Click OK to log out ...
Страница 139: ...Programming Guide 69 Index ...