Toshiba ID EDGE, Описание

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Appendix – Specifications
IPedge Net and IP Telephone Bandwidth Requirements
IPedge General Description 01/12
101
IP edge Net and IP Telephone Bandwidth
Requirements
The amount of bandwidth required for communications over a particular IP network segment
depends on the number of voice channels supported, the anticipated call setup traffic, and how
much other data network traffic is present.
The quality of service (Excellent, Good, Fair, and Poor) provided by IP edge Net channels and IP
telephones depends heavily on the LAN parameters as shown in Table 11 . This table shows the
amount of bandwidth required for each IP edge Net IP voice call (without data traffic) based on the
interval and the CODEC.
Table 11 IP edge Net IP and IP Telephone Quality of Service
IP Network Quality Parameters
Speech
Excellent: No one
perceives delay.
1
1. Ratings of Excellent, Good, Fair, Poor were based on the tester in a quiet room and the tester could not see the
other call party.
Good: Very few
people perceive
delay.
1
Fair: Some people
may perceive
delay.
1
Poor: Many people
may perceive delay.
1
IP telephones is
usable even with a
“Poor” rating if delay
is acceptable.
Latency (Round trip delay)
2
2. When selecting router equipment, the Latency, Jitter, Packet loss and Packet error conditions above should be
considered as well as the bandwidth. Bandwidth can be calculated with the CODEC and packet size. For better
results, more bandwidth may be required, depending on the amount of overall data traffic. For more details on QoS
refer to “A Handbook for Successful VoIP Deployment: Network Testing, QoS, and More” by John Q. Walker, NetIQ
Corporation on www.netiq.com.
20ms or less 50ms or less 100ms or less 200ms or less
Jitter
2
20ms or less 50ms or less 50ms or less 50ms or less
(-10 ms ~ +10ms) (-25ms ~ +25ms) (-25ms ~ +25ms) (-25ms ~ +25ms)
Packet loss
2
1×10
-3
or less 1×10
-3
or less 1×10
-3
or less 1×10
-3
or less
Packet error
2
1×10
-4
or less 1×10
-4
or less 1×10
-4
or less 1×10
-4
or less
Speech quality dependency on
CODEC parameters Speech quality as the combination of the above network environment and the
CODEC parameters.
CODEC and
packet interval
in ms
Bandwidth per
channel (Single
direction, control
channel included)
G.711 at 20ms i 88kbps
3
3. Use this number to estimate the bandwidth needed for the CODEC and IP headers required to achieve an expected
Quality of Service (Excellent, Good, etc.). When planning you should allow extra bandwidth, especially when mixing
voice and data.
Excellent Good Fair Poor
G.711 at 40ms i 76kbps
3
Excellent Good Fair Poor
G.729A at 40ms 20kbps
3
Good Good Fair Poor
G.729A at 80ms 14kbps
3
Good Fair Poor Poor