The DS field replaces the IPv4 TOS octet and the IPv6 Traffic Class octet, and six bits of it carry the DSCP that selects the per-hop behaviour at each node.
Checked 2026-10-02
Six bits of the DS field are used as a codepoint (DSCP) to select the PHB a packet experiences at each node.
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- DiffServ DS field
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 2474
- Checked
- 2026-10-02
Sources
- RFC 2474: Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers — IETF / RFC Editor · tier 1 standards and regulators · Section 3
Cite this note
APA
WarmTransfer. (2026, October 2). Troubleshooting voice QoS markings that are stripped or ignored: source note voice-qos-troubleshooting-rfc2474-dscp-six-bits. WarmTransfer. https://warmtransfer.net/knowledge/claims/voice-qos-troubleshooting-rfc2474-dscp-six-bits
BibTeX
@misc{warmtransfer-claim-voice-qos-troubleshooting-rfc2474-dscp-six-bits,
title = {Troubleshooting voice QoS markings that are stripped or ignored: source note voice-qos-troubleshooting-rfc2474-dscp-six-bits},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/voice-qos-troubleshooting-rfc2474-dscp-six-bits},
note = {Source note voice-qos-troubleshooting-rfc2474-dscp-six-bits, checked 2026-10-02}
}