Ipedge Net And Ip Telephone Bandwidth Requirements - Toshiba IP edge General Description Manual

Appendix – Specifications

IPedge Net and IP Telephone Bandwidth Requirements

IPedge 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 IPedge Net channels and IP
telephones depends heavily on the LAN parameters as shown in
amount of bandwidth required for each IPedge Net IP voice call (without data traffic) based on the
interval and the CODEC.
Table 13 IPedge Net IP and IP Telephone Quality of Service
IP Network Quality Parameters
Latency (Round trip delay)
2
Jitter
2
Packet loss
2
Packet error
Speech quality dependency on
CODEC parameters
CODEC and
packet interval
in ms
G.711 at 20ms i
G.711 at 40ms i
G.729A at 40ms
G.729A at 80ms 14kbps
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.
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.
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.
120
Excellent: No one
perceives delay.
2
20ms or less
20ms or less
(-10 ms ~ +10ms) (-25ms ~ +25ms) (-25ms ~ +25ms)
-3
1×10 or less
-4
1×10 or less
Speech quality as the combination of the above network environment and the
CODEC parameters.
Bandwidth per
channel (Single
direction, control
channel included)
3
88kbps Excellent
3
76kbps Excellent
3
20kbps Good
3
Good
Table
Speech
Good: Very few Fair: Some people
1
people perceive may perceive
1 1
delay. delay.
50ms or less 100ms or less
50ms or less 50ms or less
-3 -3
1×10 or less 1×10
-4 -4
1×10 or less 1×10
Good
Good
Good
Fair
13. This table shows the
Poor: Many people
may perceive delay.
IP telephones is
usable even with a
"Poor" rating if delay
is acceptable.
200ms or less
50ms or less
(-25ms ~ +25ms)
-3
or less 1×10 or less
-4
or less 1×10 or less
Fair Poor
Fair Poor
Fair Poor
Poor Poor
IPedge General Description
1
03/16