Source note · Cisco IP phone registration and TFTP and ITL and CTL
When a phone cannot verify a signature or certificate from its CTL or ITL, it contacts a TVS server to verify it.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- TVS
- Deployment
- on-premises
- Region
- not restricted
- Release range
- Release 15 and SUs
- Checked
- 2026-09-24
Sources
- Security Guide for Cisco Unified Communications Manager, Release 15 and SUs - Default Security — Cisco Systems · tier 2 current vendor documentation · Default Security chapter, Trust Verification Service section
Cite this note
APA
WarmTransfer. (2026, September 24). Cisco IP phone registration and TFTP and ITL and CTL: source note cisco-phone-registration-tvs-fallback. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-registration-tvs-fallback
BibTeX
@misc{warmtransfer-claim-cisco-phone-registration-tvs-fallback,
title = {Cisco IP phone registration and TFTP and ITL and CTL: source note cisco-phone-registration-tvs-fallback},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cisco-phone-registration-tvs-fallback},
note = {Source note cisco-phone-registration-tvs-fallback, checked 2026-09-24}
}