Source note · Troubleshooting fax over IP failures
In Cisco fax relay debugs, bad CRC errors on received T.30 frames indicate corrupted signals and lead to Failure To Train (FTT) responses.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco IOS voice gateways
- Subsystem
- T.30
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-10-02
- Checked
- 2026-10-02
Sources
- Troubleshoot Fax Relay — Cisco Systems · tier 2 current vendor documentation · debug fax relay t30 output discussion
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-bad-crc-causes-ftt. WarmTransfer. https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-bad-crc-causes-ftt
BibTeX
@misc{warmtransfer-claim-fax-over-ip-troubleshooting-bad-crc-causes-ftt,
title = {Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-bad-crc-causes-ftt},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-bad-crc-causes-ftt},
note = {Source note fax-over-ip-troubleshooting-bad-crc-causes-ftt, checked 2026-10-02}
}