Cisco recommends turning off SIP ALG or similar SIP-aware functionality on routers and firewalls in the path of Webex Calling traffic.

Checked 2026-09-25

If a router or firewall is SIP Aware, implying that the SIP Application Layer Gateway (ALG) or similar is enabled, we recommend you turn off this functionality for accurate operation of the service.
Vendor
Cisco
Product
Webex Calling
Subsystem
network requirements
Deployment
multi-tenant
Region
not restricted
Release range
current as of 2026-09-25
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). SIP ALG problems on firewalls and routers: source note sip-alg-problems-webex-recommends-off. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-webex-recommends-off

BibTeX

@misc{warmtransfer-claim-sip-alg-problems-webex-recommends-off,
  title  = {SIP ALG problems on firewalls and routers: source note sip-alg-problems-webex-recommends-off},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/sip-alg-problems-webex-recommends-off},
  note   = {Source note sip-alg-problems-webex-recommends-off, checked 2026-09-25}
}

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