Source note · Troubleshooting fax over IP failures
For G.711 faxing, Bandwidth says ECM is not supported and speeds are limited to 9600 or 14.4k, and recommends setting the fax machine to its lowest baud rate with error correction mode off.
Checked 2026-10-02
G711 still has issues with ECM (Error Correction Mode, which isn't supported today)
- Vendor
- Bandwidth
- Product
- Bandwidth SIP trunking
- Subsystem
- pass-through
- Deployment
- multi-tenant
- Region
- us
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Bandwidth T.38 faxing support guide — Bandwidth Inc. · tier 2 current vendor documentation · Recommended guidelines for VoIP faxing
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-bw-g711-ecm-low-baud. WarmTransfer. https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-bw-g711-ecm-low-baud
BibTeX
@misc{warmtransfer-claim-fax-over-ip-troubleshooting-bw-g711-ecm-low-baud,
title = {Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-bw-g711-ecm-low-baud},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-bw-g711-ecm-low-baud},
note = {Source note fax-over-ip-troubleshooting-bw-g711-ecm-low-baud, checked 2026-10-02}
}