This article is one in a series to assist in the setup, troubleshooting, and maintenance of Cisco Small Business products.
Q. How do I improve my fax completion rates?A.
In order to improve fax completion rates on the SPA2100, make sure:
- The SPA2100's firmware is the current version
- You have enough bandwidth for uplink and downlink. For G.711 fallback, ~100Kbps is recommended. For T.38, allocate at least 50Kbps.
In addition, configure these parameters:
- Set Network Jitter Buffer to Very High
- Set Jitter Buffer Adjustment to Disable
- Set Call Waiting to No
- Set 3-Way Calling to No
- Set Echo Canceller to No
- Set Silence Suppression to No
- Set Preferred Codec to G.711
- Set Use Preferred Codec Only to Yes
Note: For T.38 fax support, enable the feature by setting Fax Passthru Method to ReINVITE under the Line tabs. Note that if a T.38 call cannot be set up, then the call should automatically revert to G711 fallback.
If you are using a Cisco media gateway, make sure it is configured with T.38 for the SPA2100 corresponding dial peer. The dial peer should include:
- Fax Protocol should be set to T.38
- Fax Rate should be set to Voice
- Fax-Relay ECM should be set to Disable
- Fax NSF should be set to 000000
- No VAD
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