Source note · Call blocking and analytics labeling remediation
Bandwidth documents the 603+ Reason header as SIP cause 603 with a text parameter carrying a version value, the blocking party's identity, and a redress contact given as a URL, telephone number or email.
Checked 2026-09-24
Reason:SIP;cause=603;text="v=analytics1;url=https://example.com;id=12345";location=LN
- Vendor
- Bandwidth
- Product
- Bandwidth voice network
- Subsystem
- blocking-notification
- Deployment
- multi-tenant
- Region
- us
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- SIP 603+ FAQ — Bandwidth Inc. · tier 2 current vendor documentation · FAQ: 'What does SIP 603+ look like'
Cite this note
APA
WarmTransfer. (2026, September 24). Call blocking and analytics labeling remediation: source note call-blocking-labeling-603plus-reason-header. WarmTransfer. https://warmtransfer.net/knowledge/claims/call-blocking-labeling-603plus-reason-header
BibTeX
@misc{warmtransfer-claim-call-blocking-labeling-603plus-reason-header,
title = {Call blocking and analytics labeling remediation: source note call-blocking-labeling-603plus-reason-header},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/call-blocking-labeling-603plus-reason-header},
note = {Source note call-blocking-labeling-603plus-reason-header, checked 2026-09-24}
}