Source note · Call blocking and analytics labeling remediation
Bandwidth states that from March 2026 it applies no code remapping, no retries or route advance, and header integrity to SIP 603 responses, passing reason phrases and Reason headers through transparently when their syntax is valid.
Checked 2026-09-24
SIP 603 response phrases and Reason headers will be passed transparently as long as they use valid syntax
- Vendor
- Bandwidth
- Product
- Bandwidth voice network
- Subsystem
- blocking-notification
- Deployment
- multi-tenant
- Region
- us
- Release range
- from March 2026
- Checked
- 2026-09-24
Sources
- SIP 603+ FAQ — Bandwidth Inc. · tier 2 current vendor documentation · FAQ: processing rules section
Cite this note
APA
WarmTransfer. (2026, September 24). Call blocking and analytics labeling remediation: source note call-blocking-labeling-bandwidth-passthrough. WarmTransfer. https://warmtransfer.net/knowledge/claims/call-blocking-labeling-bandwidth-passthrough
BibTeX
@misc{warmtransfer-claim-call-blocking-labeling-bandwidth-passthrough,
title = {Call blocking and analytics labeling remediation: source note call-blocking-labeling-bandwidth-passthrough},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/call-blocking-labeling-bandwidth-passthrough},
note = {Source note call-blocking-labeling-bandwidth-passthrough, checked 2026-09-24}
}