Source note · Troubleshooting Cisco IP phone registration
After the CTL request the phone requests the ITL file, which the TFTP server returns with 200 OK, and then requests its configuration file.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Unified Communications Manager
- Subsystem
- TFTP
- Deployment
- on-premises
- Region
- not restricted
- Release range
- current as of 2026-09-24
- Checked
- 2026-09-24
Sources
- Troubleshoot IP Phone Unregistration Issues in CUCM — Cisco · tier 2 current vendor documentation · Troubleshoot IP Phone Unregistration Issues in CUCM > configuration file download sequence
Cite this note
APA
WarmTransfer. (2026, September 24). Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-itl-200. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-itl-200
BibTeX
@misc{warmtransfer-claim-cisco-phone-registration-troubleshooting-itl-200,
title = {Troubleshooting Cisco IP phone registration: source note cisco-phone-registration-troubleshooting-itl-200},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cisco-phone-registration-troubleshooting-itl-200},
note = {Source note cisco-phone-registration-troubleshooting-itl-200, checked 2026-09-24}
}