RFC 3264 says using connection address 0.0.0.0 to put a call on hold is no longer recommended because it prevents RTCP on held streams and does not work with IPv6 and breaks connection-oriented media.

Checked 2026-09-24

Its usage for putting a call on hold is no longer recommended, since it doesn't allow for RTCP to be used with held streams, doesn't work with IPv6, and breaks with connection oriented media.
Vendor
IETF
Product
SIP
Subsystem
legacy hold
Deployment
any
Region
not restricted
Release range
RFC 3264 as published
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). Hold resume and conference signaling: source note hold-resume-conference-3264-zero-addr-not-recommended. WarmTransfer. https://warmtransfer.net/knowledge/claims/hold-resume-conference-3264-zero-addr-not-recommended

BibTeX

@misc{warmtransfer-claim-hold-resume-conference-3264-zero-addr-not-recommended,
  title  = {Hold resume and conference signaling: source note hold-resume-conference-3264-zero-addr-not-recommended},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/hold-resume-conference-3264-zero-addr-not-recommended},
  note   = {Source note hold-resume-conference-3264-zero-addr-not-recommended, checked 2026-09-24}
}

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