Tandem Rehoming; How It's Done, and Why You Should Consider It.

Posted by John Sarkis on Jun 22, 2021 12:35:44 PM
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The ongoing adoption of a full IP network and changing regulatory environment demands that telecom service providers examine their network infrastructure to determine how they can change operations to increase efficiency and profitability. Many communications service providers are constrained by legacy tandem networks that are difficult and expensive to maintain. This has caused telcos to consolidate their older tandem switches to extend other’s life cycles or upgrading to more modern tandems. In each case, the process of moving network lines from one switch to another has been coined with the term rehoming

The Cutover Process

In basic terms, a switch cutover is a process of moving lines and trunks over to a new switch, along with routing other new subscriber lines and trunks to the new hardware. This can be done for regular events such as signal maintenance testing, and major changes like tandem rehoming projects and switch consolidation. The most successful cutovers occur when all lines are relocated to the new tandem without any customers knowing that their lines are connected to a new switch. 


Historically, cutovers would involve an extreme amount of preplanning and physical labor since each trunk would have to be physically cut by an employee. An example of that is shown in the video above, taken in an AT&T central office in 1984. These cutovers required a huge amount of preparation and analysis prior to the cutover. Special attention was needed to ensure a smooth migration to the new switch, involving a series of commands that need to be run on both the old and new tandems as well as a manual ‘stare and compare’ analysis to ensure the trunk groups are provisioned identically prior to the actual cutover.

This manual process was an intensive task performed by highly trained and well-paid employees. However, this same task can be done today by Artificial Intelligence while improving the accuracy and speed of the ‘Stare and Compare’ process, all while avoiding the risk of human error. 

Tandem Rehoming

There are a variety of factors in play today that encourage tandem rehoming. Most of these factors revolve around cost-cutting measures that help improve profitability. As each year passes, older switches become more outdated, meaning that they become more costly, harder to repair, and less efficient than newer hardware. Tandem rehoming is becoming the option that many carriers have already chosen as the plan of action for this dilemma, and are consolidating their tandems to cut costs. 

Some other reasons that make switch re-homing potentially appealing include;

  • Switch End-of-Life 

Carriers are beginning to face end-of-life scenarios for their current switching platform, which can include both legacy digital and first-generation switches. Spare and replacement parts for these switches are becoming more scarce and harder to find. As legacy switches are decommissioned, the components taken from the older equipment can increase the lifespan of other older generation switches. 

  • Equipment Cost Savings 

With the deactivation of older switches, there is less equipment to purchase and maintain. With fewer switches, providers will see cost savings through no longer needing to purchase redundant equipment, and in turn providing less maintenance and support.

  • Property Savings and Conversions

Tandem switches are often housed in central buildings that are costly to upkeep. As communications and media networks switch to cloud-based infrastructure, most of those facilities will eventually look less like typical central offices and more like data centers. It’s important that the facilities that support this infrastructure will be converted accordingly.

  • Obtain Advanced Services at Lower Cost

Next-generation switches provide a variety of potential advanced services, some of which can be costly to deploy for a small number of subscribers that need the feature. By consolidating switches, customers can migrate to the newer switches and those costs can be spread across a much larger subscriber base, lowering the costs for all participating providers.

Tandem Rehoming is an expenditure that is inevitable, and beneficial in the long run. 

ATS has developed a solution to automate the retrieval of data from the tandems as well as validate all files, thus eliminating the need for a manual ‘Stare and Compare’. Automation allows telcos to accomplish more in the cutover process by utilizing fewer resources and allowing team members to work on higher-priority assignments. Automation also ensures that every action is performed identically – resulting in high quality, reliable results and alleviating the need for process re-work.

With 25 years of background in Telecom and experience with tandem switch rehoming, ATS provides a variety of switching solutions to provide seamless trunk migration. Contact us for more information about how we can help minimize costs and simplify the rehoming process for you. 

Topics: Rehome