Source note · Troubleshooting fax over IP failures
Cisco fax relay disables ECM by having the DSP firmware modify the T.30 Digital Identification Signal (DIS) so the machines do not negotiate ECM.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco IOS
- Subsystem
- ECM
- Deployment
- on-premises
- Region
- not restricted
- Release range
- IOS command reference dated 2007
- Checked
- 2026-10-02
Sources
- Cisco IOS Voice Command Reference - F — Cisco Systems · tier 2 current vendor documentation · fax-relay ecm-disable, Usage Guidelines
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-ecm-disable-edits-dis. WarmTransfer. https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-ecm-disable-edits-dis
BibTeX
@misc{warmtransfer-claim-fax-over-ip-troubleshooting-ecm-disable-edits-dis,
title = {Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-ecm-disable-edits-dis},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-ecm-disable-edits-dis},
note = {Source note fax-over-ip-troubleshooting-ecm-disable-edits-dis, checked 2026-10-02}
}