RFC 4594 reserves CS7 (decimal 56) for future use and recommends dropping or re-marking CS7 packets at ingress to a DiffServ domain.

Checked 2026-09-24

Vendor
IETF
Product
Differentiated Services
Subsystem
trust boundary
Deployment
any
Region
not restricted
Release range
current as of 2026-09-24
Checked
2026-09-24

Sources

Cite this note

APA

WarmTransfer. (2026, September 24). QoS marking and queuing for voice: source note qos-marking-rfc4594-cs7-reserved. WarmTransfer. https://warmtransfer.net/knowledge/claims/qos-marking-rfc4594-cs7-reserved

BibTeX

@misc{warmtransfer-claim-qos-marking-rfc4594-cs7-reserved,
  title  = {QoS marking and queuing for voice: source note qos-marking-rfc4594-cs7-reserved},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/qos-marking-rfc4594-cs7-reserved},
  note   = {Source note qos-marking-rfc4594-cs7-reserved, checked 2026-09-24}
}

Read in context