Legal Firm Modernizes Communications with Microsoft Teams Phone System

Replacing an Aging On-Premises Phone System Under a Tight Deadline

A large Chicago-based law firm with multiple locations had already completed a major data migration to SharePoint and OneDrive and moved its ERP system to the cloud. The final step in the firm's cloud transformation was retiring its on-premises Mitel phone system so its remaining servers could be decommissioned entirely.

The firm's support and maintenance contract for the Mitel system was expiring, and the project needed to be completed before a 12-month renewal was required. Leadership wanted a cloud VoIP solution but needed help identifying the right fit and executing quickly.

IntelliSuite IT Solutions was engaged to:

• Evaluate Mitel's VoIP offering against Microsoft Teams Phone for the firm's specific needs
• Handle full planning, design, and deployment of the selected solution
• Deliver the project in under two months, with zero disruption to attorneys and staff

A Phased Migration to Microsoft Teams Phone

IntelliSuite recommended Microsoft Teams Phone, since the firm was already fully deployed on Microsoft 365 and staff used Teams daily. The migration was executed in three coordinated phases.

Planning & Discovery

• Discovery sessions with leadership to define requirements and technical architecture
• Letter of Agency (LOA) processing and phone number port requests
• Validation of required IP connectivity and network readiness
• Hardware procurement — desk phones, conference room phones, and headsets
• Microsoft licensing assessment and procurement

Core System Configuration

A proof of concept with a strategically selected pilot group validated functionality before full rollout, with weekly status meetings keeping the project on time and on budget. Configuration included:

• Teams global calling policies
• Call routing architecture, auto attendants, and call queues
• Azure configuration updates to support voice
• E911 configuration and location services
• Individual user phone setup
• Admin & end user training resources
• Assignment of Teams Phone and Calling Plan licenses
• Employee communication plan execution

Cutover

The cutover was scheduled after business hours and communicated well in advance to avoid any downtime or disruption. Go-live activities included:

• Number porting and activation
• End-to-end testing and go-live support
• Delivery of architecture and configuration documentation
• Transition to ongoing IT support

The project was completed on time and on budget, giving the firm the fully cloud-based technology landscape it set out to achieve.

Successful Migration to a 100% Cloud Environment

Retiring the on-premises phone system allowed the firm to shut down its remaining server environment entirely, completing its transition to a modern, reliable, cloud-based technology landscape that supports secure remote and in-office work while meeting industry compliance requirements.

Increased Productivity

Attorneys and staff now use a single application — Microsoft Teams — for voice calling, video meetings, messaging, and file sharing, simplifying workflows and enhancing collaboration firm-wide.

Meaningful Cost Savings

Shutting down the server environment eliminated ongoing hardware maintenance costs. The larger savings came from canceling legacy phone service and phone system support contracts — cutting thousands of dollars per month in costs across the firm's multiple offices.

Improved Scalability & Flexibility

As a cloud-based platform, Teams Phone lets the firm scale its communications infrastructure up or down simply by adding or removing licenses — with no physical hardware required.

Enhanced Remote Workforce Experience

Staff can now make and receive calls from anywhere with an internet connection — from a computer, headset, or the Teams mobile app — supporting remote work without exposing personal cell numbers and ensuring continuous connectivity regardless of location.

Peace of Mind

The firm's Microsoft 365 security and compliance policies now extend to its phone system as well. Staff adjusted to the new system immediately, with uninterrupted operations in a fully cloud-based environment — the outcome the firm set out to achieve.