Source note · Troubleshooting fax over IP failures
A T.38 re-INVITE carries an m=image ... udptl t38 media line with attributes such as T38FaxVersion, T38FaxRateManagement (transferredTCF), T38FaxMaxBuffer, T38FaxMaxDatagram and T38FaxUdpEC (t38UDPRedundancy).
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Cisco Unified Border Element
- Subsystem
- SDP
- Deployment
- on-premises
- Region
- not restricted
- Release range
- as documented 2013-08-14
- Checked
- 2026-10-02
Sources
- CUBE Third-Party Interoperability Fax Guidelines — Cisco · tier 2 current vendor documentation · Example T.38 ReINVITE SDP trace
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-reinvite-sdp-attrs. WarmTransfer. https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-reinvite-sdp-attrs
BibTeX
@misc{warmtransfer-claim-fax-over-ip-troubleshooting-reinvite-sdp-attrs,
title = {Troubleshooting fax over IP failures: source note fax-over-ip-troubleshooting-reinvite-sdp-attrs},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/fax-over-ip-troubleshooting-reinvite-sdp-attrs},
note = {Source note fax-over-ip-troubleshooting-reinvite-sdp-attrs, checked 2026-10-02}
}