Source note · SIP registration failures
Cisco recommends turning off SIP ALG or similar SIP-aware functions on routers and firewalls for Webex Calling, because some ALG implementations cause firewall-traversal problems even though the traffic is encrypted.
Checked 2026-09-25
we recommend you turn off this functionality for accurate operation of the service.
- Vendor
- Cisco
- Product
- Webex Calling
- Subsystem
- network
- Deployment
- multi-tenant
- Region
- not restricted
- Release range
- current as of 2026-09-25
- Checked
- 2026-09-25
Sources
- Port Reference Information for Webex Calling — Cisco Systems, Inc. (help.webex.com) · tier 2 current vendor documentation · section 'SIP Application Layer Gateway'
Cite this note
APA
WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-wxc-disable-sip-alg. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-wxc-disable-sip-alg
BibTeX
@misc{warmtransfer-claim-sip-registration-failures-wxc-disable-sip-alg,
title = {SIP registration failures: source note sip-registration-failures-wxc-disable-sip-alg},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-wxc-disable-sip-alg},
note = {Source note sip-registration-failures-wxc-disable-sip-alg, checked 2026-09-25}
}