A-5
Cisco AVVID Network Infrastructure Enterprise Quality of Service Design
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Appendix A Reference Information
When to Enable cRTP
When to Enable cRTP
ESE Lab testing of QoS features has revealed performance ceilings resulting from enabling
recommended WAN QoS features. cRTP is the most CPU intensive QoS feature and should be used with
caution on WAN aggregation routers that are serving a large number of remote sites. Specifically:
·
The 7200VXR with NPE-400 can successfully compress and decompress 360 simultaneous RTP
streams, with FRTS and LLQ engaged.
·
The 7500 with VIP4-80 can compress and decompress between 240 and 300 simultaneous RTP
streams, with FRTS and LLQ engaged.
Note
These results are based on only transmitting voice and voice control traffic.
Tip
For full details refer to the WAN Platform Performance Guide and the cRTP Scalability on Cisco WAN
Aggregation Platform case-study (internal).
Likewise, there are performance impacts on remote-branch routers when cRTP is enabled, as shown in
.
Figure A-1
cRTP Performance Impact on Remote Branch Routers
Tip
For full details refer to the QoS Branch Performance Guide (internal).
81038
128K
256K
1751
2651
3640
3725
4224
768K
2048K
4500K
Linkspeed
CUPU%
0
10
20
30
40
50
60
70
80
90