Troubleshooting Vofr; Call Failure In Huawei-Compatible Mode; Poor Vofr Quality - 3Com MSR 50 Series Configuration Manual

2404 C 138: V FR C
HAPTER O

Troubleshooting VoFR

Call Failure in
Huawei-Compatible
Mode

Poor VoFR Quality

ONFIGURATION
Symptom
Calls cannot be connected in Huawei-compatible mode
Analysis
In the Huawei-compatible mode, calls can be connected only when the frame
relay is normal, voice entities are configured correctly, and a sufficient bandwidth
is reserved for voice.
Solution
Use the display interface serial command to check that frame relay is
■
correctly configured on the two sides.
Check that the protocols of X.25 over frame relay work normally. You can use
■
the display fr pvc-info command to check the status of X.25 and LAPB or use
the display x25 vc command to check X.25 VC is congested.
Check that a voice bandwidth has been reserved for the corresponding DLCI.
■
Check that a frame relay class is configured for the DLCI and that a voice
bandwidth is configured for the frame relay class.
Check that the voice entities are properly configured.
■
Symptom
The VoFR quality is poor.
Analysis
A high VoFR quality requires sufficient bandwidth.
Solution
Check that the physical bandwidth of frame relay is sufficient (10 kbps in
■
accordance with G.729 and 9 kbps in accordance with G.723).
Check that a fragment size is configured for all DLCIs on the same interface
■
and that the fragment size is small enough. You can use the debugging fr
fragment interface serial command to view the packet fragment size.