Source note · Cisco IP phone registration and TFTP and ITL and CTL
The 2017 registration technote states the default Expires value in the phone's REGISTER to the primary Unified CM is 120 seconds, and that keep-alive REGISTERs to secondary servers carry Expires 0.
Checked 2026-09-24
- Vendor
- Cisco
- Product
- Cisco Unified Communications Manager
- Subsystem
- SIP registration
- Deployment
- on-premises
- Region
- not restricted
- Release range
- as written 2017; not re-validated for Release 15
- Checked
- 2026-09-24
Sources
- General Information for CUCM IP Phone Registration/Deregistration Troubleshooting — Cisco Systems · tier 2 current vendor documentation · SIP phone registration / KeepAlive discussion
Cite this note
APA
WarmTransfer. (2026, September 24). Cisco IP phone registration and TFTP and ITL and CTL: source note cisco-phone-registration-sip-register-expires. WarmTransfer. https://warmtransfer.net/knowledge/claims/cisco-phone-registration-sip-register-expires
BibTeX
@misc{warmtransfer-claim-cisco-phone-registration-sip-register-expires,
title = {Cisco IP phone registration and TFTP and ITL and CTL: source note cisco-phone-registration-sip-register-expires},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/cisco-phone-registration-sip-register-expires},
note = {Source note cisco-phone-registration-sip-register-expires, checked 2026-09-24}
}