Source note · Unified CM SIP normalization and transparency scripts
Practitioners report that Unified CM, acting as a back-to-back user agent, drops non-standard SIP headers between call legs unless a transparency script passes them through.
field report · Checked 2026-09-25
- Vendor
- Cisco
- Product
- Unified Communications Manager
- Subsystem
- SIP transparency
- Deployment
- on-premises
- Region
- not restricted
- Release range
- unspecified; 2019 field report
- Status
- field report
- Checked
- 2026-09-25
Sources
- CUCM SIP Normalization and Transparency Scripting Example — Technology or Die (independent blog) · tier 5 independent technical research · Core problem / introduction
Cite this note
APA
WarmTransfer. (2026, September 25). Unified CM SIP normalization and transparency scripts: source note cucm-sip-normalization-b2bua-drops-headers. WarmTransfer. https://warmtransfer.net/knowledge/claims/cucm-sip-normalization-b2bua-drops-headers
BibTeX
@misc{warmtransfer-claim-cucm-sip-normalization-b2bua-drops-headers,
title = {Unified CM SIP normalization and transparency scripts: source note cucm-sip-normalization-b2bua-drops-headers},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cucm-sip-normalization-b2bua-drops-headers},
note = {Source note cucm-sip-normalization-b2bua-drops-headers, checked 2026-09-25}
}