This article provides a structured, self‑service migration framework for Partners and Customers those migrate calling environments to Webex Calling - Dedicated Instance (DI).

The migration practices and milestones described in this article are based on the Webex Setup Assist program methodology and reflect the extensive real‑world experience of Cisco delivery, engineering, and development teams. These methods have been refined through hundreds of thousands unique customer location deployments over the past seven years, including migrations from BroadCloud, BroadWorks, Spark Calling, Unified CM (UCM), Hosted Collaboration Solution (HCS), and third‑party PBX platforms. The guidance applies to a wide range of customer environments, from single‑seat deployments to large‑scale implementations exceeding 100,000 seats and hundreds of locations, and follows long‑established, proven Cisco processes to ensure consistency, quality, and operational efficiency throughout the migration lifecycle.

The article assumes that readers are already familiar with Webex Calling - Dedicated Instance licensing, the Webex Control Hub administrative model, and the baseline Unified Communications Manager software and features.

Let's be honest — the word migration rarely sparks excitement in an IT team. It sparks questions. "What breaks?" "Who does the work?" "What do we lose control over?" "Is this even realistic while we're already stretched thin keeping the lights on?" These are not signs of resistance to progress; they are the instincts of seasoned professionals who understand that moving a mission-critical calling platform is not a weekend project. Voice is the one service where users notice a two-second glitch before they notice a two-week outage planning effort — and that reality makes every change feel heavier than it should.

The good news? The numbers tell a very different story than the fear does. In well-structured cloud migrations, roughly 95% of engineering effort is invested in preparation, and only 5% in the actual change. Even better, most of that 95% is made up of activities your team already performs as part of normal Day 2 operations — inventory hygiene, certificate management, dial plan reviews, device lifecycle tracking, and documentation. In other words, the bulk of the "migration work" is work you are already doing. This structured approach simply channels it toward a defined outcome, at a pace that fits inside your existing operational rhythm rather than on top of it.

The "mission impossible" feeling also fades once you see that every migration can be fully rehearsed. A small, representative pilot lets you validate the end-to-end process, integrations, failover behavior, and user experience before a single production user is touched. Nothing is left to chance on cutover day — because cutover day is simply the repetition of a process you've already executed successfully. And should anything unexpected occur, rollback is a mirror of the cutover itself, bounded by a clear maintenance window. Predictability replaces anxiety.

Yes, moving to Dedicated Instance does mean letting go of some control — specifically over the infrastructure and virtualization layers. But consider what you gain back: the hours your team spends patching hypervisors, chasing hardware alerts, managing OS-level security, and planning capacity refreshes. That time returns to the business, where it can be spent on what actually differentiates your organization — user experience, adoption, integrations, and the services your stakeholders truly care about. You're not losing control; you're trading undifferentiated heavy lifting for strategic focus.

What you receive in exchange is a platform tightly integrated with the most advanced Calling, Meetings, and Contact Center portfolio on the market, backed by Cisco's engineering depth and a partner ecosystem refined through hundreds of thousands of deployments. You keep the full power of the familiar Unified CM ecosystem — the same features, the same reliability, the same administrative model your team already knows — now paired with Control Hub, a modern, user-oriented management and analytics umbrella that is genuinely simple to learn. Upgrades, updates, and critical vulnerability patching on the latest software are managed by Cisco, on Cisco-certified compute, with the same (or better) reliability you expect from your on-premises environment.

So, yes — change carries risk. But not changing carries its own, quieter risk: falling behind on features, addressing constant complexity of changes, release upgrades and vulnerabilities, stretching your team on infrastructure that no longer differentiates the business, and delaying an inevitable transition until it must be done under pressure. The structured, gated approach that follows is designed to make this migration what it should be: well-prepared, low-drama, and highly validated — executed mostly through work you're already doing, toward a platform built for where collaboration is heading next.

From Confidence to a Plan: How This Guide Is Organized

To turn that confidence into an executable roadmap, this guide walks you through a seven-gated migration process, each phase with clear entry and exit criteria, lessons learned from the field, and pre-checks that prevent the most common surprises:

• Project Initiation
• Discovery & Assessment
• Planning
• Implementation
• Freeze
• Go Live
• Transfer to Day 2

One of the reasons this model works so well is that the risk to your production environment is deliberately front-loaded to near zero and only rises in a controlled, final step. Here is what to expect at each stage:

Production Impact	Phases
No impact	Project Initiation, Discovery & Assessment, Planning
Minimum impact	Implementation
Limited to operations processes	Freeze
Direct impact	Go Live

In practical terms: most of the journey happens safely alongside your existing environment. By the time you reach the moment that touches production, every integration has been built, every process has been rehearsed, and every fallback has been verified.

Throughout the guide, we reference the key information resources you'll rely on during the migration and well into Day 2:

• Cisco Calling Sales Connect — Cisco Calling Sales Connect Link
• Help.webex.com — authoritative product and configuration documentation
• Webex Spaces — direct access to Cisco experts and peer communities for real-time questions

With the framework set and the resources in hand, let's walk through each phase in detail — starting where every successful migration starts: Project Initiation.

Impact on production: NO impact

• Identify key stakeholders

Remember that it is not only about technical teams and impacted business teams, but also Partners involved. Here are the example of required stakeholders:

• IT management
• Business management
• Voice services team
• Contact centers team
• Networking team
• DNS/DHCP team
• Security team
• IAM team (eg Entra, AD, SSO)
• Change board
• MACD partner
• Managed services partner
• 3d party integration vendors (Paging, Fax, Recording etc)
• Local, on-prem support
• RedSky /Public safety team.

• Choice of Project leader or Project manager.

Considering that migrations to Dedicated Instance involve more complex coordination than traditional “Application level only” integrations it is desirable to have team member assigned to drive internal Project management and all associated tasks like weekly calls, internal teams coordination, external vendors engagement, coordination of changes etc.

• Sync on inputs you start project with

There are multiple advantages and reasons why there is a strategy taken to migrate to Dedicated Instance. It is important to baseline vision over future solution.

Are there any changes like clusters consolidation, dial plan, new features planned?

Do you migrate software endpoints “as is” or migration assume move to Webex App?

What is the relationship of users to Contact centers?

• Get up to the speed with Dedicated Instance

Introduction to Dedicated Instance: Introduction to Dedicated Instance

BDM (Business Decision Maker Slides) BDM

TDM (Technical Decision Maker Slides) TDM.

Impact on production: NO impact

Discovery and assessment is a continuation and the utilization of the information that was obtained during previous team sync meetings on inputs with the goal to identify all the necessary scope elements those will be the basis for professional project and technical project plan development

• Existing Cluster setup

Define existing on-Prem setup with all the features and integrations done. Here are the examples to look at:

• Applications and sizing,
• Locations,
• IP addressing,
• How users synchronized/provisioned (local, ldap),
• Authentication configured (SSO),
• CA vs Self-signed certificates,
• Security mode,
• ILS/GDPR use,
• Features,
• Special focus on cross-site features like Extension Mobility,
• CER/911 integration,
• Use of MRA,
• CDRs,
• Voicemails and integration with O365,
• Jabber vs WebexApp
  • In case Jabber migration, there should be close focus on how existing Jabber endpoints configured (eg xml configuration, voice service domain) and what are the options for reconfiguration like use of SCCM. Here are standard scenarios noted: Configure Jabber
• List of Devices with focus to check for
  • Deprecated devices (there are no new devices added on deprecation list since Rel12.0x) Deprecated phones
  • End of support devices (Devices could be still registered to any software release, but are not supported from Day2 perspective)
  • CSR-Compatibility-Matrix-Interactive.html
  • Special Restriction devices 7925, 7940, 7960 Register old phone models to Dedicated-Instance
    • Tools in help:

      Dedicated Instance Pre-Migration Assistant: Generate Assessment reports

      The Pre-Migration Assistant in Control Hub helps you gather source data and check prerequisites for migrating from UCM to Dedicated Instance using a third-party tool. Before migration, it assesses readiness, provides checklists, and lets you compare data between your on-premises cluster and Dedicated Instance.

      To run Assistant, your on-prem Cluster must be on-boarded to Webex Cloud-Connected UC environment. Overall description and prerequisites you can find here: WebexCloud-ConnectedUC

      On-boarding process for UCM: Set-up Webex Cloud Connected-UC

      List of important insights you can get as output from Pre-Migration Assistant in xls easily readable format:

      • Nodes and running software
      • Enterprise parameters
      • List of SIP trunks
      • List of Application users, roles
      • Number of devices (and full list of devices), Route groups and Partitions, Locations, End users
      • CM Groups, Device pools
      • Health status of DB replication
      • Installed COPs
      • Numbering plans
      • Phone services
      • Remote destinations
    • Webex Spaces to support with your specific questions:

      Ask UCM Cloud & Dedicated Instance: webexteams://im?space=5db6bb40-d3c7-11e9-a319-df8a35abe85a

      Ask RedSky External - E911 Solutions Plus Partner Join: https://eurl.io/#fWfT1SnOz

      Ask Webex Setup Assist - Webex Calling and DI: webexteams://im?space=76beab50-084b-11ed-abc8-ab581010b1de.

Impact on production: minimum impact on existing production environment

Cisco best practices in terms of Dedicated Instance Migration process represented down below:

Peering/Connectivity

Network Architecture with detailed descriptions of Edge connect scenarios for Webex Calling, Dedicated Instance and Meetings. PA_Edge_Connect_Design.pdf

*Document should be used carefully, as describes multiple scenarios those could be conflicting or complementing to each other, depends on exact use case. Exact reference to Dedicated Instance can be found in chapter “Edge Connect for Dedicated Instance Architecture“

Webex Edge Connect

Webex Edge Connect Most common questions, notes:

• Dedicated Instance 2 links is a “must”
• 4 links is an option but “crossing” is not allowed, those are used in “pairs”
• Any DI traffic prioritization towards one of the links is NOT supported and generally not applicable, as each side/DC advertise its unique subnet /25 Dedicated Instance data center locations.

This is also explained in the mentioned Network Architecture document as per below:

Impact on production: with impact limited to operations processes

The purpose of Freeze phase is to move data from source system to target Dedicated Instance and execute necessary validations to assure successful cutover. We do recommend 2-3 weeks timeframe for the freeze to make sure that teams have necessary time for data move, data consistency checks, test failovers and related testing.

In case there is a need for MACD during freeze phase, required changes should be completed on both systems.

There are multiple ways and tools available for data move/copy. Generally, we do recommend use Active/Inactive partitions and tools as per below:

UCM:

BAT export/import and associated scripting

Bulk Administration Guide for Cisco Unified Communications Manager, Release 15 and SUs: CUCM_b_bulk-administration-guide-15.html.

External tools for UCM migrations like Yarnlab.

Unity:

• Cisco Unity Tools. Collection of free Cisco Unity and Cisco Unity Connection related tools.

https://www.ciscounitytools.com/index.html

We do recommend use of Cobras for Unity migrations.

CER:

Manual, Bulk Export/Import

Upon configuration data moved, consider next important items/actions:

• Manual or via Option 150 on DHCP in relation to test group re-pointing of different phone models to new DI TFTP. Having certificates consolidation done you can test both: migration and rollback scenario
• Reconfiguration of test gateway, if available
• Preparation of Gateways configuration templates for actual production cutovers. Scripting, if needed.
• Move of WebexApp user via change of Calling behavior at CH
• Move of Jabber via defined previously login method and home cluster change
• Test of basic call flows and functionality up to environment capabilities:
  • Check of consistency of behavior being on-net or connected via VPN
  • Test of MRA with phone and Software endpoint
  • PSTN
  • Test of 911 Service

• Dedicated Instance Tier1 Support (TAC) Dedicated-Instance Tier-1 support

• Service requests associated with listed topics: How to raise a service request
  • DNS entry
  • Firewall Updates
  • Firmware Upload
  • Cloud Connectivity
  • Audit Log Settings
  • UC Application Management
  • DI-MT Inter-op SIP trunks
  • UC application lifecycle
  • Infrastructure as a Service
    • Partner Operations Guide

• Partner Operations Guide

  This is one of the most important documents that explains Technical support, Change Management, Incident Management, Updates, Upgrades, Capacity management, Certificates management, DRS Partner-operations-guide

This is one of the most important documents that explains Technical support, Change Management, Incident Management, Updates, Upgrades, Capacity management, Certificates management, DRS Partner operations guide

• Responsibility Matrix

Document explains RACI split in-between Partner, Cisco and Customer during on-boarding and Operations Responsibility assignment matrix

• Ask RedSky Webex Space webexteams://im?space=7074fce0-489a-11ea-89f3-8f977dd07aa0.