Enter your current Cisco Unified Communications Manager version — get the exact hop plan to 14 or 15, with EoL dates, compatibility, and SIP/SCCP rules verified against Cisco's published guidance.
The CUCM Upgrade Path Explorer turns Cisco's compatibility matrix and end-of-life bulletins into a plain-English answer for your exact environment. Give it your current CUCM version and your target, and it returns whether the upgrade is a single L2 hop, a two-stage refresh upgrade, or blocked entirely because of SCCP endpoints or unsupported VM hardware. It also flags the paired version you'll need for IM&P, Unity Connection, UCCX, Expressway, Jabber, and phone firmware — because half the upgrade failures we see in the field are downstream compatibility, not CUCM itself. Every answer is backed by a Verify on Cisco.com link so you can double-check before your change window.
Fill in the form and click Plan my upgrade — your personalized hop plan appears here.
A one-hop plan fits one maintenance window. A two-hop plan needs two windows, separated by at least a week of soak time at the intermediate version so replication, CDR, and LDAP sync prove stable before the second jump.
L2 upgrades keep the old partition and can roll back in under an hour. Refresh upgrades rebuild the OS — rollback means restoring a DRS backup, which is measured in hours and carries real risk. Always schedule a refresh upgrade with a fresh DRS the morning of.
CUCM 15 drops SCCP entirely. If you carry SCCP endpoints, migrate them to SIP firmware before the upgrade, not during. The tool flags this up-front so you don't discover it at 2 a.m. in your cutover call.
Cisco's upgrade matrix looks intimidating because it rolls three different decisions into one table: the supported upgrade type (L2 vs refresh), the supported version pairs, and the paired dependencies on IM&P, Unity Connection, UCCX, and Expressway. Once you separate those, the logic is simple. Any version at 11.5 or newer can L2-upgrade directly to 14 or 15 as long as your hardware meets the target's OS requirements. Anything older than 11.5 — 9.x, 10.0, 10.5, 11.0 — has to stop at 12.5 SU7 first, using a refresh upgrade, then L2-upgrade to 14 or 15.
The second trap is endpoint firmware. CUCM 14 still accepts SCCP phones but marks them deprecated. CUCM 15 removes SCCP support entirely — which means if you run the L2 upgrade to 15 with a single SCCP phone left on the network, that phone stops registering the moment the publisher comes back up. The fix is to flip the default device-pool device-security-profile to SIP, run Bulk Administration to change the device protocol on all remaining SCCP phones, and confirm registrations in RTMT before kicking off the upgrade. Your 88xx, 78xx, 8800-series endpoints all support SIP from firmware 11.x onwards. Older 79xx-series phones (7940, 7960, 7970) are hard-blocked at SCCP and will not run on CUCM 15 — they need to be swapped to 78xx/88xx or retained on a 12.5 island cluster.
The third consideration is your paired servers. An upgrade is rarely just CUCM — IM&P has to move in lock-step because they share a database schema. Unity Connection and UCCX need to be inside their supported compatibility window or calls and voicemail break at cutover. Expressway is more forgiving (X14.2+ pairs with CUCM 14; X15.0+ pairs with CUCM 15), but an out-of-window Expressway will block MRA and B2B video. This tool pulls the compatible pairings directly from our weekly-refreshed copy of Cisco's compatibility matrix so you don't have to dig through the PDF.
Finally, a note on when to run an upgrade. CUCM 12.5 has an LDoS of 2028-06-30 and is still a perfectly supportable production version. If your environment is mostly stable, there is no urgency to jump to 15 in 2026 — the benefit cases are Webex Calling integration, Cloud Connect, and the simplified SIP-only architecture. If you're running 11.5 or older, you are in urgent territory: 11.5 reached LDoS on 2026-01-31, and no further security patches will ship. That's the upgrade we plan most often in our Health Assessment engagements.
Yes. 11.5 → 15 SU1 is a supported direct path using an L2 upgrade, provided your hardware/VM meets 15 requirements and all endpoints are SIP (SCCP is deprecated in 15). 11.5 itself reached LDoS on 2026-01-31, so this upgrade is urgent.
Versions older than 11.5 (9.x, 10.0, 10.5, 11.0) cannot perform a direct upgrade to 14 or 15 because of intermediate schema and database migration changes. Cisco's documented path is to hop through 12.5 SU7 first — a refresh upgrade, then an L2 upgrade to the target.
No. SCCP is fully deprecated in CUCM 15. All endpoints must be running SIP firmware before the upgrade. CUCM 14 still supports SCCP but flags it as deprecated.
A Refresh Upgrade installs a new OS as well as a new CUCM version and is required for major OS jumps (for example 10.x → 12.5). An L2 upgrade reuses the existing OS partition and is faster — it's supported for same-family hops such as 12.5 → 14 or 14 → 15.
A single-hop L2 upgrade on a publisher + 2 subscribers typically runs 3–5 hours including DB replication verification. A two-hop refresh upgrade (e.g. 10.5 → 12.5 SU7 → 15 SU1) usually spans two change windows over 2–3 weeks including soak time.
IM&P — yes, it's version-locked to CUCM and must move in the same change window. Unity Connection should be inside its compatibility window by the time CUCM is upgraded, but the Unity upgrade itself can run in a separate, earlier window to reduce risk.
Regional hospital, 2,400 endpoints, Pub + 3 subs, mixed 88xx SIP and 7965 SCCP phones. IM&P paired, Unity 12.5 SU6.
800-endpoint cluster, all SIP already, stuck on 10.5 because of a legacy third-party recording integration.
350-endpoint cluster, risk-averse CIO, no appetite for a major jump this year.
The Network & UC Health Assessment is a written, independent review of your actual environment — not vendor marketing. Includes a full upgrade runbook with pre-checks, DRS, CAR purge, replication verification, endpoint validation, and roll-back steps sized to your specific cluster.