Source note · Passing call context with SIP UUI and custom headers
RFC 7434 requires the sending application to put a protocol discriminator octet (per ITU-T Q.931) as the first octet of isdn-uui data.
Checked 2026-10-02
The sending application MUST include a protocol discriminator octet
- Vendor
- not restricted
- Product
- not restricted
- Subsystem
- ISDN UUI interworking
- Deployment
- any
- Region
- not restricted
- Release range
- RFC 7434
- Checked
- 2026-10-02
Sources
- RFC 7434: Interworking ISDN Call Control User Information with SIP — IETF / RFC Editor · tier 1 standards and regulators · Section 9
Cite this note
APA
WarmTransfer. (2026, October 2). Passing call context with SIP UUI and custom headers: source note sip-uui-context-passing-rfc7434-protocol-discriminator. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-uui-context-passing-rfc7434-protocol-discriminator
BibTeX
@misc{warmtransfer-claim-sip-uui-context-passing-rfc7434-protocol-discriminator,
title = {Passing call context with SIP UUI and custom headers: source note sip-uui-context-passing-rfc7434-protocol-discriminator},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-uui-context-passing-rfc7434-protocol-discriminator},
note = {Source note sip-uui-context-passing-rfc7434-protocol-discriminator, checked 2026-10-02}
}