00 · Header

T6 · Migration

Post-migration Validation

After a group moves, you test a subset and you test the queues and hunts that moved with them. After everyone has moved, Unified CM’s remaining job can be transit between the PSTN gateways and Webex Calling. Cleanup then removes the discovery records, the DHCP options, and the virtual machines. Dedicated Instance post-migration reports live in T5-R06.

Expand all sections

01 · Executive summary

Five lines, then why it matters

• On-net tests cover transfer, hold, forwarding, and conferencing. PSTN tests cover inbound to users, queues, hunts, and auto attendants, plus outbound caller ID. [cite:1]
• Hunt tests check the configured algorithm, overflow, forwarding, no-answer, and that membership and routing match what was on Unified CM. The article states that as the test goal. [cite:1]
• If hybrid trunking was used from the start, the guide says there is no extra PSTN migration step after the users move, beyond decommissioning Unified CM and the Local Gateways. [cite:2]
• Put migrated directory numbers in a hidden partition so calling search spaces prefer the cloud path. [cite:2]
• Analytics cover media quality, call history, call queue, hunt group, and auto attendant. Troubleshooting can integrate ThousandEyes and Meraki. The detailed guide is “Troubleshoot Webex Calling calls in Control Hub.” [cite:2]

02 · Architecture map

What remains, then what you delete

flowchart LR
  PSTN[PSTN gateways] --> UCM[Unified CM transit]
  UCM --> LGW[Local Gateway]
  LGW --> WXC[Webex Calling]
  WXC --> CCP[Cloud Connect]

03 · Core concepts

Test the batch, then retire the platform

Cloud Connect cutover

What the optimize list removes

04 · Ecosystem & sister technologies

Glossary, map, sisters, edges

Glossary

Acceptance test

The implement article’s sample checks after a group moves. The article says the section is not exhaustive. [cite:1]

Transit role

After users and endpoints are on Webex Calling, Unified CM can remain only to pass calls between PSTN gateways and Webex Calling through the Local Gateway. [cite:2]

Hidden partition

Where the guide says to place migrated directory numbers so search spaces prefer the cloud path. [cite:2]

Cloud Connect cutover

The four-step move of premises PSTN onto a Cloud Connect partner, including a disposable test location. [cite:2]

Horizon Mobility

The name the December 2025 guide prints for the dispatchable-location product you update when the building network changes. [cite:2]

Mind map

mindmap
  root((Validation))
    Pilot
    Acceptance
    Cloud Connect
    Cleanup
    Analytics

Sister technologies

Integration edges

Cross-platform bridges

Future hooks

Canon plan. Keep the DI report names out of this room until someone is reading T5-R06. Cisco. The guide already points troubleshooting detail at help.webex.com article frj1efb. That pointer is the published next step. [cite:2]

Ecosystem troubleshooting

05 · Flow

From a pilot to an empty rack

06 · Config

Paths you can cite

1. After each batch, compare extensions and DIDs with the Unified CM directory. Place on-net and PSTN calls. Check overlaps. [cite:1]
2. If a queue moved, confirm distribution against the logic you configured. The article’s examples are round robin, longest idle, and simultaneous ring. [cite:1]
3. For a hunt, confirm the algorithm, overflow, forwarding, no-answer, and that membership matches Unified CM. [cite:1]
4. Before a Cloud Connect cutover, provision a test location, point it at the partner, call through it, and deprovision it. [cite:2]
5. Port every number on the Unified CM PSTN trunk together. On the day, set each location’s PSTN and verify inbound and outbound. [cite:2]
6. Remove the SRVs and DHCP options, hide the migrated DNs, update Horizon Mobility when the building network changes, and delete the virtual machines the guide names. [cite:2]
7. Open Control Hub analytics for media quality, call history, queues, hunts, and auto attendants. For a failed call, follow Troubleshoot Webex Calling calls in Control Hub, article frj1efb. [cite:2]

07 · Limits

What is quantified

08 · Troubleshooting

Ten validation misses

09 · Self-question ladder

Twelve rungs

10 · Lab

A paper lab. Do not delete a production SRV to learn this.

• Goal: sequence a Cloud Connect cutover and name the discovery records that come out last.
• Prereq: q0pgpb acceptance section and the December 2025 optimize chapter. No live DHCP change.
• Step 1. Pilot omits the hunt group. Expected: the article says hunts move with the users.
• Step 2. Grade a Calling queue as “Longest Available.” Expected: that name is not the sentence in q0pgpb.
• Step 3. Port one site’s numbers and leave the rest on the trunk. Expected: the guide says all numbers, same time.
• Step 4. List the SRVs and the DHCP options. Expected: the three names and options 66 and 150.
• Evidence: the hidden-partition sentence and the frj1efb pointer.
• Break it: tell users their Unity Connection messages came across. Recovery: the guide says there is no native migration of messages or greetings.
• Reflection: which DI report you almost pasted into this multi-tenant chapter.

11 · Quiz

Twelve questions

12 · Audio

Slots for Studio

13 · Interview

Oral answers

30 seconds. Validate a representative pilot with the same tools you will use later, and move voicemail, attendants, queues, and hunts with those people. After each group, test a subset. The written acceptance list is a sample, not a complete script.

2 minutes. Check extensions and DIDs, on-net and PSTN, and overlaps. On-net means transfer, hold, forwarding, and conferencing. PSTN means the call lands on the right user or queue and the far end sees the right caller ID. For a Calling queue, the article’s examples are round robin, longest idle, and simultaneous ring. That sentence is not the Webex Contact Center pattern list. For a hunt, match the algorithm, overflow, and the membership you had on Unified CM.

30 seconds, transit. When everyone is on Webex Calling and PSTN is still local, Unified CM only forwards calls between the gateways and Webex Calling. Do not shut it off in that state.

2 minutes, cleanup. Test Cloud Connect on a throwaway location, then deprovision it. Port every number on the Unified CM trunk together and flip every location the same day. If you started with hybrid trunking, the guide says you skip that PSTN migration and only decommission Unified CM and the gateways. Then remove the UDS, login, and collab-edge SRVs, DHCP options 66 and 150, and the dial-peers. Hide the old directory numbers. Delete Unified CM, Expressway, and Unity Connection. Do not promise that old voicemail messages came along. Update Horizon Mobility when the switches or the floor plan change.

What you will not say. You will not recite Dedicated Instance post-migration report names in this room. You will not call the acceptance section complete. You will not invent steps from the troubleshooting article; you will name frj1efb and stop.

14 · Citations

1. Implement the migration from Unified CM to Webex Calling — help.webex — article q0pgpb — help.webex.com article q0pgpb — retrieved 2026-10-14. The retrieved markdown did not print a header date. re-check Pilot scope. Acceptance tests for numbers, PSTN, on-net, queues, and hunts. The section says it is not exhaustive. Queue examples are round robin, longest idle, or simultaneous ring.
2. Calling: Transitioning from Unified CM to Webex Calling — Cisco deployment guide — December 2025 — cisco.com DEPLOYMENT_CALLING_Unified_CM_to_Webex_Calling.pdf — retrieved 2026-10-14. Transit role. Four Cloud Connect steps. Hybrid-trunking exception. DNS, DHCP, dial-peer, VM, E911, and hidden-partition cleanup. Horizon Mobility. Analytics. ThousandEyes and Meraki. Article frj1efb. No native Unity Connection message migration. Acceptance narrative in the same guide restates on-net and voicemail checks.
3. Configure trunks, route groups, and dial plans for Webex Calling — help.webex — article n0xb944 — help.webex.com article n0xb944 — retrieved 2026-10-14. Verify Call Routing path, the four call sources, and the result fields. Folded from the slice-5 draft, which cited this page and did not carry the December 2025 cleanup list.
4. Troubleshoot Webex Calling calls in Control Hub — help.webex — article frj1efb — help.webex.com article frj1efb — retrieved 2026-10-14. Roles. 21 days. Calls appear after they end. Segments. CSV of 100. JSON report. Not necessarily root cause. Folded from the slice-5 draft.

15 · Re-engineer later

• Open questions: q0pgpb header date. Whether a later Calling queue article replaces “round robin, longest idle, or simultaneous ring” inside the implement page.
• Facts still marked TODO-verify: treating this cleanup list as the Dedicated Instance decommission.
• Facts still marked re-check: the acceptance examples, because that retrieval had no header date.
• Assets missing: analytics screenshot, audio.
• Ideas for v1.0: a teardown card with the three SRV names and two DHCP options, regenerated from the December 2025 guide at review time.
• Next review: re-check the optimize chapter before a decommission window.