91´ÎÔª

Project Status

Estimated project completion: see Projects

Executive Summary

91´ÎÔª (MCC) will migrate from Integrated Services Digital Network (ISDN) Primary Rate Interfaces (PRIs) to 50 concurrent Session Initiation Protocol (SIP) channels provided by CallTower. This transition supports MCC’s 2025–2030 Strategic Plan by improving student communication, streamlining processes, and investing in secure, modern campus infrastructure.

The project will ensure reliable communications for faculty and staff with students and the community at large. This effort enables MCC to leverage its existing Cisco Unified Communications Manager (CUCM), the college’s Private Brach Exchange (PBX), platform while greatly reducing dependency on outdated legacy technology. The project will be carried out in collaboration with college leadership and departmental stakeholders. Special attention will be placed on ensuring business continuity, number porting for the 1,400 Direct Inward Dial (DID) numbers, and failover planning.

The estimated project cost is $91,903.60 spread over 36 months. Monthly fee of $2423.60 for 36 months, and a onetime port fee of $4654.00 for 1400 DIDs.

Business Need & Background

Currently MCC relies on two AT&T ISDN PRIs to connect the PBX to the publicly switched telephone network (PSTN). PRIs are legacy technologies that are increasingly costly, limited in scalability, and subject to service decommission timelines. AT&T has begun phasing out PRI services across Texas as part of the industry-wide shift to all-IP telephony. Maintaining PRI lines creates unnecessary expense and operational risk. The college is no longer able to make changes to the ISDN PRIs as of October 15, 2025. MCC has been informed that the ISDN PRIs will be End of Support (EoS) on December 31, 2025. SIP trunking offers MCC several advantages:

• SIP reduces recurring monthly carrier costs compared to PRIs, particularly for long-distance and international calls.(SIPTRUNK Team, 2023)
• SIP services over MCC’s dual internet connections will provide more resiliency to our telephone system in the event of physical damage to the internet lines.
• At the service provider level SIP trunks can failover to alternate data centers or redundant paths in case of outages.(CallTower,n.d.)
• Additional call paths can be provisioned as needed without new physical circuits.
• SIP supports MCC’s path toward a cloud based Unified Communication (UC) model, including Microsoft Teams.
• SIP is the industry standard for voice connectivity, ensuring MCC is aligned with modern telecom practices.

By migrating to SIP trunking, MCC aligns with industry standards, reduces IT operational overhead, and ensures a modern, secure, and resilient communication platform that supports faculty, staff, and students.

1. Service Continuity: Replace 2 PRIs with 50 concurrent SIP trunks while preserving all 1,400 DIDs.
2. Elimination of Possible Price Hike: Texas DIR pricing for our current PRI service expires on December 31, 2025. Historically, when Texas DIR pricing expired for other services, there was a price increase from $300 per month to $7000 per month.
3. Redundancy: Introduction of multiple service entry paths to campus through our dual internet connections and service provider’s datacenter high availability capabilities.(CallTower,n.d.)
4. Scalability: Enable flexible expansion for future growth without costly physical circuits.
5. Vendor Support: Utilize CallTower’s managed SIP trunking service with Cisco CUCM integration. 

Project Description & Scope

The project will prioritize migrating from connectivity to the Public Switched Telephone Network (PSTN) to the internet, ensuring the college can place and receive calls.

The project will replace the two existing AT&T PRIs with 50 concurrent call SIP paths provide by CallTower. The current 1400 Direct Inward Dialed (DID) number will be ported from AT&T to CallTower, allowing existing extensions to remain unchanged and ensuring uninterrupted communication with the community, employee and students.

Project Schedule (Original)

Project Management & Governance (Original)

• Phone Service Migration (PRI to SIP) Project Charter

Last updated: 12/1/2025