Source note · SD-WAN considerations for voice
Cisco advises disabling SIP ALG on firewalls and NAT devices in the Webex Calling path, because some SIP ALG implementations break firewall traversal.
Checked 2026-09-24
certain SIP ALG implementations can cause issues with firewall traversal
- Vendor
- Cisco
- Product
- Webex Calling
- Subsystem
- ports and firewall
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Port Reference Information for Webex Calling — Cisco Systems, Inc. (help.webex.com) · tier 2 current vendor documentation · Firewall / NAT guidance
Cite this note
APA
WarmTransfer. (2026, September 24). SD-WAN considerations for voice: source note sdwan-voice-disable-sip-alg. WarmTransfer. https://warmtransfer.net/knowledge/claims/sdwan-voice-disable-sip-alg
BibTeX
@misc{warmtransfer-claim-sdwan-voice-disable-sip-alg,
title = {SD-WAN considerations for voice: source note sdwan-voice-disable-sip-alg},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sdwan-voice-disable-sip-alg},
note = {Source note sdwan-voice-disable-sip-alg, checked 2026-09-24}
}