Cisco Cisco Customer Response Solution Downloads Guía De Diseño
6-5
Cisco Unified Contact Center Express Solution Reference Network Design, Release 4.1
Chapter 6 Bandwidth, Security, and QoS Considerations
Estimating Bandwidth Consumption
Note
These calculations are based on G.711 using a sampling rate of 64 kbps speech encoding and the G.729
using 8kbps. This means one second of speech encoded into the G.711 CODEC requires 65,536 bits (or
8,192 bytes) to represent one second of sound.
using 8kbps. This means one second of speech encoded into the G.711 CODEC requires 65,536 bits (or
8,192 bytes) to represent one second of sound.
For full-duplex connections, the bandwidth speed applies to both incoming and outgoing traffic. (For
instance, for a 100-Mbps connection, there is 100 Mbps of upload bandwidth and 100 Mbps of download
bandwidth.) Therefore, an IP phone call consumes the bandwidth equivalent of a single stream of data.
In this scenario, a G.711 IP phone call with no silence suppression and containing 20 milliseconds of
speech per packet requires 87.2 kbps (174.4 / 2) of the available bandwidth.
instance, for a 100-Mbps connection, there is 100 Mbps of upload bandwidth and 100 Mbps of download
bandwidth.) Therefore, an IP phone call consumes the bandwidth equivalent of a single stream of data.
In this scenario, a G.711 IP phone call with no silence suppression and containing 20 milliseconds of
speech per packet requires 87.2 kbps (174.4 / 2) of the available bandwidth.
and
display the percentage of total bandwidth available, based on the network
connection, that is required for simultaneous monitoring sessions handled by a VoIP provider.
The following notes apply to the bandwidth requirements shown in Table 6-2 and Table 6-3:
•
The bandwidth values are calculated based on the best speed of the indicated connections. A
connection's true speed can differ from the maximum stated due to various factors.
connection's true speed can differ from the maximum stated due to various factors.
•
The bandwidth requirements are based on upload speed. Download speed affects only the incoming
stream for the IP phone call.
stream for the IP phone call.
•
The values are based upon each voice packet containing 20 milliseconds of speech.
•
The number of bytes in each packet include the entire Ethernet encapsulation.
•
The data represents the CODECs without silence suppression. With silence suppression, the amount
of bandwidth used may be lower.
of bandwidth used may be lower.
•
The data shown does not address the quality of the speech of the monitored call. If the bandwidth
requirements approach the total bandwidth available and other applications must share access to the
network, latency (packet delay) of the voice packets can affect the quality of the monitored speech.
However, latency does not affect the quality of recorded speech.
requirements approach the total bandwidth available and other applications must share access to the
network, latency (packet delay) of the voice packets can affect the quality of the monitored speech.
However, latency does not affect the quality of recorded speech.
•
The data represents only the bandwidth required for monitoring and recording. It does not include
the bandwidth requirements for other Cisco Agent Desktop modules as outlined in other sections of
this document.
the bandwidth requirements for other Cisco Agent Desktop modules as outlined in other sections of
this document.
G.729
40
39.2
G.729
50
34.6
G.729
60
31.4
Table 6-1
Per-Call Packet Size Bandwidth Requirements (continued)
CODEC
Milliseconds of speech per
packet
packet
Bandwidth required (Kbps) for a
call
call
Table 6-2
Available Upload Bandwidth Percentage for Simultaneous Monitoring Sessions with G.711 CODEC
Number of Simultaneous
Monitoring Sessions
Monitoring Sessions
Percentage of Available Bandwidth Required (No Silence Suppression)
100 Mbps
10 Mbps
1.544 Mbps
640 kbps
256 kbps
128 kbps
64 kbps
56 kbps
Call only
0.1
0.9
5.6
13.6
34.1
68.1
Not supported (NS)
1
1
0.3
2.6
16.8
40.9
NS
NS
NS
NS
2
0.4
4.4
28.1
68.1
NS
NS
NS
NS
3
0.6
6.1
39.3
95.4
NS
NS
NS
NS