Huawei eSpace IAD - Page 41

eSpace IAD
Troubleshooting
2 Analyzing and Rectifying Faults
Issue 02 (2012-02-29)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
36
Table 2-3 Fax/Modem service performance and network quality
Service Type
Performance
in a Good
Network
Performance
in a Poor
Network
Performance
in a Bad
Network
Modem
Transfer
Proved
Failed
Failed
Fax
Transfer
Proved
Failed
Failed
For example:
− If SIP is used, run the sip send-capability fax pri command to set the faxing mode to
T.38.
TERMINAL(advanced-config)#sip send-capability fax pri 0 t38 redundancy 2
If the fax encoding/decoding priority configuration fails, run the display sip send-capability command
to view the configuration result, and find out the priority for the required encoding/decoding type. Run
the undo sip send-capability fax pri command to delete the priority, and run the sip send-capability
fax pri command to set the priority again.
− If MGCP is used, run the mgcp soft-parameter command to set the faxing mode to
t38v2.
TERMINAL(advanced-config)#mgcp soft-parameter fax-mode t38v2

If the network quality is good, go to Step 6.
Step 6 Capture IAD network packets to verify that both ends of media negotiation use the same
codec. If downspeeding is performed, check whether downspeeding is successful.

If no, the network quality is poor.

If yes, go to Step 8.
Step 7 Check whether the packet consists of the following parameters:

a=T38FaxFillBitRemoval:0

a=T38FaxTranscodingMMR:0

a=T38FaxTranscodingJBIG:0

a=T38FaxUdpEC:t38UDPRedundancy
These parameters are not supported by the IAD.
Step 8 Check whether echo exists in the voice sent from the core network.

If yes, contact the core network management personnel to find out the time when the
echo is generated.

If no, go to Step 9.
Step 9 Contact Huawei technical support.
----End