/mcpDetermine the Severity of Jitter
The presence of excessive jitter can be confirmed through Cisco IOS by completing these steps.
Once a call is up and active, and jitter is suspected, Telnet to one of the gateways involved.
1.
Enable Terminal Monitor in order to be able to see console messages through your Telnet session.
Note: This step is not necessary if you are connected to the console port.
2.
Enter the show voice call summary command. Output similar to this appears:
PORT CODEC VAD VTSP STATE VPM STATE
============ ======== === ==================== ======================
1/0/0 − − − FXSLS_ONHOOK
1/0/1 g729r8 y S_CONNECT FXSLS_CONNECT
Select the call where the jitter is experienced. In this example, it is 1/0/1.
3.
To look at this specific call, enter the show voice call command.
In this example, it is show voice call 1/0/1. The output that is given comes from the DSP that handles
the call and is similar to this:
1/0/1 vtsp level 0 state = S_CONNECT
vpm level 1 state = FXSLS_CONNECT
vpm level 0 state = S_UP
MS−2621−3B# DSP VOICE VP_DELAY STATISTICS
Clk Offset(ms): 0, Rx Delay Est(ms): 50
Rx Delay Lo Water Mark(ms): 50, Rx Delay Hi Water Mark(ms): 7
DSP VOICE VP_ERROR STATISTICS
Predict Conceal(ms): 0, Interpolate Conceal(ms): 0
Silence Conceal(ms): 0, Retroact Mem Update(ms): 0
Buf Overflow Discard(ms): 0, Talkspurt Endpoint Detect Err: 0
DSP VOICE RX STATISTICS
Rx Vox/Fax Pkts: 1187, Rx Signal Pkts: 0, Rx Comfort Pkts: 0
Rx Dur(ms): 150200, Rx Vox Dur(ms): 23740, Rx Fax Dur(ms): 0
Rx Non−seq Pkts: 0, Rx Bad Hdr Pkts: 0
Rx Early Pkts: 0, Rx Late Pkts: 0
DSP VOICE TX STATISTICS
Tx Vox/Fax Pkts: 7129, Tx Sig Pkts: 0, Tx Comfort Pkts: 0
Tx Dur(ms): 150200, Tx Vox Dur(ms): 14259, Tx Fax Dur(ms): 0
4.