Dedicated Instance – customer deployment models

Introduction

Webex Calling Dedicated Instance (Dedicated Instance) is a private cloud option for customers who need a dedicated UC solution deployed in the Cisco cloud. Dedicated Instance is an add-on to Webex Calling. Dedicated Instance includes the standard UC applications that are traditionally deployed on-premises such as Unified Communications Manager, Unity Connection, IM & Presence, Expressway, and CER (U.S. customers). This solution offers customers the ability to customize their dial plan and integrate with a plethora of third-party applications that integrate with Cisco today.

General considerations

Dedicated Instance Activation

Cisco deploys a private customer instance in the Dedicated Instance cloud that is geo-redundant within the region. Cisco is responsible for the cluster sizing based on the licenses purchased and the input provided by partner/customer in the First Time Setup Wizard (FTSW). Unified CM call control, IM&P for message and presence, Cisco Unity Connection for voicemail and Expressway for Mobile Remote Access are the core dedicated applications deployed for the customer. Cisco Emergency Responder (CER) is deployed for North American customers for emergency calling.

User synchronization

In Dedicated Instance, customer end-user data is synchronized with the Control Hub cloud (also known as the identity service), and Dedicated Instance Unified CM subsequently synchronizes from the Control Hub. The Control Hub directory synchronization is a shared feature across all Webex services, including Webex Meetings, Webex Calling, and Dedicated Instance. For authentication, the user synchronization feature functions only when Single Sign-On (SSO) is enabled. Without SSO, the directory synchronization feature is not supported.

Additionally, Dedicated Instance supports native user data synchronization options available with on-premises Unified CM integration.

Domain

For Dedicated Instance, Cisco provides the FQDN for the service in each region with the following format <customer>.<region>.wxc-di.webex.com (for example, xyz.amer.wxc-di.webex.com).

DNS records for this FQDN needs to be resolvable from the customer’s internal DNS server to support on-premises devices connecting to the Dedicated Instance. To facilitate resolution, the customer needs to configure a Conditional Forwarder, for this FQDN, on their DNS server pointing to the Dedicated Instance DNS service.

Refer to DNS requirements for more information.

Deployment models

You should be familiar with the technical aspects of the Webex Calling Dedicated Instance( Dedicated Instance) for a deeper understanding of the various choices explained in these scenarios.

For each case study we’ll provide a high-level view and analyze the following Dedicated Instance aspects based on the customer data points:

Dedicated Instance service high-level view
Connectivity
PSTN
Integrations

Dedicated Instance customer (CCP, Redsky)

Customer data:

Number of users: 25,000
Existing solution: on-premises Unified CM
PSTN: SP provided
Related services: Webex Meetings, O365 email
Network: MPLS WAN with Equinix peering locations including SJC, DFW

A U.S.-based enterprise with a national presence and a workforce of approximately 25,000 users. The organization operates from multiple office locations across the country, supporting a large-scale collaboration infrastructure.

Current State:

The customer maintains a complex on-premises Unified Communications (UC) environment, including:

Three Cisco Unified Communications Manager (Unified CM) clusters, tightly integrated with various internal business applications.
Avaya UC systems inherited through a corporate merger, which are interoperating with the existing Cisco infrastructure.
MPLS WAN backbone connecting all major offices, with Equinix peering points in San Jose (SJC) and Dallas-Fort Worth (DFW) for cloud interconnectivity.
PSTN services are provided by a third-party Service Provider (SP).
Utilizes Webex Meetings for conferencing and Microsoft Office 365 (O365) for email and productivity.

Business Drivers:

Corporate directive to transition to cloud-based solutions as part of a digital transformation initiative.
Goal to reduce on-premises hardware footprint and associated operational costs (maintenance, upgrades, IT staff overhead).
Desire to streamline the mixed UC landscape (Cisco and Avaya) and standardize on a unified platform.

Dedicated Instance - high-level view

The Dedicated Instance solution addresses the customer's cloud migration and cost reduction goals by consolidating their three on-premises Unified CM clusters into two Dedicated Instance UC clusters located in the North America region. This solution offers tight integration with Webex Meetings, providing end users with a seamless experience to upgrade calls to meetings. Additionally, Dedicated Instance includes an HTTP proxy to facilitate integration with Office 365. Dedicated Instance environment supports integration of UC applications with existing business systems and Avaya UC, thus preserving the end-user experience. PSTN connectivity is delivered through Webex Calling Cloud Connected PSTN (CCP), enabling smooth cloud-based telephony services.

The diagram shows the Dedicated Instance deployment where all users are in Dedicated Instance and PSTN is through Webex Calling Cloud Connected PSTN (CCP).

Webex Calling Dedicated Instance - high-level view

Connectivity considerations

The customer can extend their WAN to the Dedicated Instance environment using Edge Connect. In the North America region, Dedicated Instance supports Edge Connect peering at Equinix or Megaport locations. Since the customer already has a presence in Equinix, they can extend their WAN network to two Equinix sites and connect to Dedicated Instance and Webex Meetings via Edge Connect. If the customers Equinix or Megaport locations are not where the Webex POP resides, they will have to extend the connection Equinix and Megaport at their cost. Cisco requires peering at two sites within a region to ensure network-based redundancy, providing a resilient and reliable connection to the cloud environment. This setup supports the customer's cloud migration while maintaining high availability and network performance.

PSTN service

With the migration to Dedicated Instance, the customer can transition their existing PSTN service to the Webex Calling Cloud Connected PSTN (CCP) service. In the provided architecture, PSTN calls are routed from the Dedicated Instance cloud through the Webex Calling Multi-Tenant (Multi-Tenant) environment to the PSTN provider. CCP offers global cloud PSTN calling capabilities for Dedicated Instance by leveraging established CCP partner peering with Webex Calling. This setup aggregates the customer’s PSTN traffic from all locations, including Mobile and Remote Access (MRA) users, through the Webex Calling CCP service, ensuring seamless and centralized PSTN connectivity.

Refer to Cloud Connected PSTN for more information.

PSTN Service

Integrations

RedSky for E911 is an emergency call service that provides precise location services and routes emergency calls to the appropriate PSAP. This cloud-based RedSky service is tightly integrated with the Dedicated Instance environment. In a Dedicated Instance deployment, both Cisco Emergency Responder (CER) and RedSky work together to track devices and clients. On-premises phones are tracked using CER, which identifies the phone’s location and sets the correct dispatch location before routing the call to RedSky for delivery. Webex App users are tracked directly in RedSky using the HELD+ protocol, ensuring accurate location information for emergency response.

Refer to Configure E911 for Dedicated Instance for more information.

RedSky integration

Webex Calling Multi-Tenant, Dedicated Instance and Meetings customer (single peering over Edge Connect)

Customer data:

The customer has a WAN infrastructure capable of peering at multiple locations, leveraging private network connections through cloud exchange providers such as Equinix and Megaport.
The customer’s user base includes personas that align with both Multi-Tenant and Dedicated Instance deployment models, enabling flexible adoption of Cisco Webex services.
Webex Meetings is a required collaboration tool for the customer, integrated seamlessly with both Multi-Tenant and Dedicated Instance environments.

A multinational financial services firm with a global footprint and a highly distributed workforce. The organization operates across North America, Europe, and Asia-Pacific, and prioritizes secure, reliable communication and collaboration for internal and client-facing teams.

Network Infrastructure:

The firm has a robust WAN architecture designed for high availability and low-latency connectivity. They leverage private network interconnections through top cloud exchange providers such as Equinix and Megaport, enabling peering at multiple strategic locations globally. This setup provides consistent and secure access to cloud-based services and applications.

User Personas & Deployment Needs:

The organization supports a diverse user base:

Corporate employees and general staffbenefit from the agility and scalability of the Multi-Tenant Webex model.
Regulated teams such as investment banking, legal, and compliance—who require data residency, tenant isolation, and enhanced control—are aligned to the Dedicated Instance deployment model.

This hybrid model supports flexible onboarding, tailored security, and operational segmentation aligned with departmental needs.

Collaboration Strategy:

Webex Meetings is the company’s standard collaboration platform for all internal meetings, client engagements, and cross-regional communication.

Key integration benefits include:

Unified calendar and scheduling through Outlook/Exchange.
Consistent meeting quality and feature set, irrespective of user location or infrastructure backend.
Integrated security policies aligned with internal governance frameworks.

Dedicated Instance - high-level view

This hybrid Webex deployment, underpinned by a resilient WAN and private peering, enables the firm to:

Ensure high-quality, secure collaboration.
Meet compliance requirements for sensitive business units.
Scale flexibly across departments and regions without compromising performance or control.

single peering over Edge Connect

Dedicated Instance peering

Customer can utilize the Edge Connect 3.0 peering capability to consolidate Multi-Tenant, Dedicated Instance, and Webex Meetings traffic over a single peering path. This capability is supported by both Equinix and Megaport providers, enabling streamlined and efficient network connectivity for all these services through one unified peering connection.

DI peering

Refer to  Dedicated Instance Edge Connect for more information.

UC application consideration

Dedicated Instance integrates seamlessly with Webex Meetings through a SIP trunk established between the Dedicated Instance Unified CM and Webex over the Webex network. With this setup, the Webex Meetings cloud treats Dedicated Instance in a manner similar to Edge Audio.

This configuration enables features like "Call me" and "Call back" to route calls through Dedicated Instance. For example, when an end-user selects the "Call me" option to join a Webex Meeting, Webex initiates the call through Cisco's internal SIP trunk to the Dedicated Instance, which then connects to the user's phone. Similarly, when an end-user uses the "Call in" option, they make a call from their phone through the Dedicated Instance, which routes it via the internal SIP trunk to Webex Meetings.

This integration ensures that audio traffic for Meetings flows through the same Dedicated Instance peering from the customer's WAN to Cisco Webex, enhancing the quality and reliability of the call.

Dedicated Instance and Multi-Tenant customer

Customer Overview: 

Customer is a U.S.-based company with a large site which is their headquarters and several regional offices where the sales teams are distributed.

Current Environment:

Calling: On-premises Cisco Unified Communications Manager (Unified CM)
PSTN: Provided by a third-party service provider
Network: MPLS WAN with Equinix peering at SJC and DFW
Integrations: Many business applications are integrated with Unified CM

Needs:

Improve calling experience for distributed sales teams
Reduce dependency on on-prem infrastructure
Maintain existing app integrations and PSTN provider
Support hybrid and remote work

Dedicated Instance service high-level view

The Webex Calling Dedicated Instance (Dedicated Instance) solution effectively addresses all use cases for users at headquarters. For regional sales teams, Webex Calling Multi-Tenant (Multi-Tenant) is ideal, as they operate entirely over-the-top (OTT) and benefit from the latest Multi-Tenant innovations, such as Customer Assist and Webex Go. Multi-Tenant is also well-suited for the numerous smaller sites, while Dedicated Instance is a perfect fit for the remaining parts of the organization that require extensive applications and customizations.

The diagram shows the Multi-Tenant and Dedicated Instance deployment for one customer.

Multi-tenant and Dedicated Instance deployment

Connectivity consideration

Customer can do any of the peering models supported in Dedicated Instance and use the same peering for Dedicated Instance and Multi-Tenant. From the peering locations (Equinix or Megaport), the Webex backbone carries the traffic to appropriate service. Also Meeting Edge Audio can also use the same peering. The Edge Audio to use the Dedicated Instance SIP Edge component to connects to Meetings service, customer on-premises Edge Audio component (CUBE or Expressway) isn’t needed.

Guidance for splitting users between Dedicated Instance and Multi-Tenant

Considerations for Splitting the User Base Between Webex Calling Multi-Tenant (Multi-Tenant) and Dedicated Instance:

Migration: Dedicated Instance helps alleviate the challenges of enterprise calling migrations to the cloud. Customers may choose to migrate to Dedicated Instance first and then divide the user base between Multi-Tenant and Dedicated Instance as needed.
Contiguous Phone Numbers: When splitting the user base between Multi-Tenant and Dedicated Instance, it is recommended to keep contiguous phone numbers within the same call control. This simplifies dial plan and routing provisioning on both platforms.
Feature Differences: Customers splitting users across Multi-Tenant and Dedicated Instance platforms should consider that calling features are not fully harmonized between the two. It is generally advisable to keep users requiring group-based features (e.g., Call Pickup groups, Hunt groups, Manager/Secretary configurations) within the same call control platform, either Multi-Tenant or Dedicated Instance, to ensure consistency.
Endpoint Support: Dedicated Instance supports all endpoints compatible with on-premises Unified CM, including older Cisco phone models. For endpoints that cannot be migrated to Multi-Tenant, Dedicated Instance is the natural choice.
Enhanced Survivability: Dedicated Instance supports Enhanced Survivable Nodes (ESN) where a UCM node can be deployed on-premises for a full on-premise failover capability. For customers requiring high availability for critical services (e.g., hospitals), Dedicated Instance with ESN is a suitable option. Additionally, if the customer’s existing solution is Unified CM with SRST for remote sites, the same SRST can be extended to Dedicated Instance Unified CM.
Integrations: Dedicated Instance supports third-party integrations similar to on-premises Unified CM. If there are existing business workflows integrated with on-premises Unified CM, transitioning those workflows to Dedicated Instance is typically easier. User allocation can also be based on such workflow dependencies.

Directory Synchronization Considerations:

Control Hub Synchronization: The customer directory should be synchronized with the Control Hub cloud, and Dedicated Instance Unified CM will synchronize directly from the Control Hub.
Group Filters:Group filters can be configured so that Dedicated Instance Unified CM synchronizes only users designated for Dedicated Instance, rather than all users.
User Assignment: For calling services, each user must belong to either Dedicated Instance or Multi-Tenant, but not both. Ensure proper assignment of services for each user.

This approach ensures thoughtful planning and smooth operations when splitting the user base between Multi-Tenant and Dedicated Instance.

PSTN consideration

Organizations can adopt either a customer-premises Local Gateway (LGW) to connect to the PSTN or utilize Cloud-Connected PSTN services. The decision may depend on factors such as cost benefits, simplifying unified communications (UC) services through a single provider, network traffic considerations, and other business priorities.

For the Local Gateway approach, the following details apply:

Direct SIP Trunk to Dedicated Instance Unified CM: The customer configures a direct SIP trunk from Dedicated Instance Unified CM to the on-premises Local Gateway, following the Unified CM configuration guidelines.
Multi-Tenant Configuration: The Local Gateway is configured with Multi-Tenant, adhering to the Multi-Tenant guidelines. The trunk can connect via common peering or the internet.
Single Local Gateway with Split Trunking: A single Local Gateway can support two trunks—one to Dedicated Instance Unified CM and one to Multi-Tenant. However, it is recommended to split the user base so that each site is entirely in either Dedicated Instance or Multi-Tenant. As a result, from a given Local Gateway, only one trunk (to either Dedicated Instance or Multi-Tenant) is typically recommended.

For Cloud Connect PSTN, both Multi-Tenant and Dedicated Instance users can leverage the existing CCP partner peering to the Multi-Tenant platform.