Source note · SIP registration failures
Cisco describes CUCM SIP phone registration as a series of stages: DHCP addressing, TFTP download of firmware and security files (CTL/ITL), configuration file retrieval, and only then SIP REGISTER to Unified CM.
Checked 2026-09-25
- Vendor
- Cisco
- Product
- Unified Communications Manager
- Subsystem
- sip-phone-registration
- Deployment
- on-premises
- Region
- not restricted
- Release range
- document dated 2023-07-28
- Checked
- 2026-09-25
Sources
- Troubleshoot IP Phone Unregistration Issues in CUCM — Cisco · tier 2 current vendor documentation · registration process overview section
Cite this note
APA
WarmTransfer. (2026, September 25). SIP registration failures: source note sip-registration-failures-cucm-stages. WarmTransfer. https://warmtransfer.net/knowledge/claims/sip-registration-failures-cucm-stages
BibTeX
@misc{warmtransfer-claim-sip-registration-failures-cucm-stages,
title = {SIP registration failures: source note sip-registration-failures-cucm-stages},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/sip-registration-failures-cucm-stages},
note = {Source note sip-registration-failures-cucm-stages, checked 2026-09-25}
}