Registration failures attributed to SIP ALG plausibly come from Contact or Via rewriting that conflicts with the endpoint's own NAT handling. The collected vendor sources state interference in general terms but do not document a registration-specific mechanism.

inferred · Checked 2026-09-25

Vendor
multi-vendor
Product
SIP through NAT
Subsystem
registration
Deployment
on-premises, multi-tenant, hybrid
Region
not restricted
Release range
current as of 2026-09-25
Status
inferred
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-registration-failure-mechanism. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-alg-problems-registration-failure-mechanism

BibTeX

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

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