[cisco-voip] Latancy / Jitter

[STEVEN CASPER]

How about Max Jitter - we sometimes see as much as 50-60 ms though Avg
Jitter is low.

Steve

>>> "Bell, Joe" <Joe_Bell at adp.com> 06/21/06 1:14 PM >>>
According to the Enterprise QoS SRND page 1-13
(http://www.cisco.com/application/pdf/en/us/guest/netsol/ns432/c649/ccmi
gration_09186a008049b062.pdf), your spec's are:

Voice (Bearer Traffic)

A summary of the key QoS requirements and recommendations for Voice
(bearer traffic) are:

* Voice traffic should be marked to DSCP EF per the QoS Baseline and
RFC
3246.

* Loss should be no more than 1 %.

* One-way Latency (mouth-to-ear) should be no more than 150 ms.

* Average one-way Jitter should be targeted under 30 ms.

* 21-320 kbps of guaranteed priority bandwidth is required per call
(depending on the sampling

rate, VoIP codec and Layer 2 media overhead).

So, your latency is a tad bit high, but humans don't really notice it
until it is consistently above 200 ms.

Joe

 

 

 

________________________________

From: cisco-voip-bounces at puck.nether.net 
[mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Voll, Scott
Sent: Wednesday, June 21, 2006 9:58 AM
To: cisco-voip at puck.nether.net 
Subject: [cisco-voip] Latancy / Jitter

 

I'm looking at QoS stats from CM for phone calls.  Is this out of
recommended specs?

 

Jitter < 15

Lantancy < 175

 

Thanks

 

Scott



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