For VG4xx ports connected to a fax machine on Webex Calling, the guidance is to enable T.38 to override the default audio codec.
Checked 2026-10-02
- Vendor
- Cisco
- Product
- Webex Calling
- Subsystem
- VG4xx fax
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- as of article dated 2026-02-03
- Checked
- 2026-10-02
Sources
- Configure your Cisco Voice Gateway VG400, VG410, or VG420 in Control Hub — Cisco Webex · tier 2 current vendor documentation · port configuration section - fax note
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting analog phones and FXS ports with no dial tone or failed calls: source note analog-fxs-troubleshooting-vg4xx-fax-t38-port. WarmTransfer. https://warmtransfer.net/knowledge/claims/analog-fxs-troubleshooting-vg4xx-fax-t38-port
BibTeX
@misc{warmtransfer-claim-analog-fxs-troubleshooting-vg4xx-fax-t38-port,
title = {Troubleshooting analog phones and FXS ports with no dial tone or failed calls: source note analog-fxs-troubleshooting-vg4xx-fax-t38-port},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/analog-fxs-troubleshooting-vg4xx-fax-t38-port},
note = {Source note analog-fxs-troubleshooting-vg4xx-fax-t38-port, checked 2026-10-02}
}