In the telecommunications industry, people have been talking about the benefits associated with SIP trunks for years. Many RFPs have been submitted to the carriers, and many companies are piloting and implementing SIP trunks. Oftentimes, as the move to SIP trunks is considered, a carrier change is also considered. Doing so can result in significant savings; however it is a surprisingly complex activity that requires a great deal of planning, time and effort.
As organizations look to migrate from TDM to SIP trunks, two types of phone numbers must be considered: DIDs and Toll Free Numbers. For DIDs, the main concern is the ability of the new carrier to service all of an organization's DID ranges. The more complex topic--and the focus of this article--is toll free number migrations.
A migration to SIP trunks with a carrier change for toll free numbers is a major undertaking and should be viewed as a project. With that, the first task is to identify a strong project manager. I've seen the project management portion of this type of a project underestimated, and that can lead to significant delays and outages during migrations.
Along with the project comes a timeline. Think about commitments your organization has with the legacy carrier, both around the current usage commitments that must be met before migrating away from that carrier, along with any contractual dates there may be around migrating off of their platform. Building these dates into the project plan is a critical step, and if dates are missed there can be significant financial penalties. In my experience, these projects take significantly longer than expected, so I suggest building significant buffer into the project timeline.
The following are required steps that comprise the migration of toll free numbers and traffic to a new carrier:
1. Inventory and document all Toll Free Numbers: Many organizations have hundreds or thousands of toll free numbers, yet have no inventory of them. A complete inventory of toll free numbers, along with call flows and features (i.e. prompting and announcements) is required in order to replicate this information going forward.
Don't underestimate this part of the process; it is one of the most important, and most time consuming steps of the project. Some toll free numbers can be very complex with tens, hundreds, or even thousands of terms. In a large organization you may need 5-10 people working on this step. This could also be a good opportunity to clean up toll free numbers that have little to no usage, or ones that are not operational (i.e. ring no answer, ring to a busy signal, ring to a "not in service" message, etc.).
It is important to work with internal business partners on this research, since they likely know more than the IT department about many toll free numbers. For example, the marketing department may have numbers on reserve for future marketing campaigns. Those numbers will show zero usage, but if they are sunset and then the marketing campaign goes live, that will be a problem!
2. Resporg your numbers to the new carrier (RespOrg or Responsible Organization is the organization responsible for controlling and maintaining an organization's toll free numbers). This is the first step required by the carriers for the transition of the numbers.
3. Design and configure the new call routing: If the SIP trunk architecture utilizes centralized SIP trunks, you will need to determine how to get calls to your sites. This can also be a time consuming task that requires significant resources to implement. In addition, the skill set to implement the call routing on an in-house platform is different than the one used to implement routing within a toll-free network.
4. Pre-production Testing: Test the new call routing as much as possible. Toll-free number testing can be difficult since each number is unique in production environments, but depending on the routing architecture some level of testing can be performed.
5. Schedule Toll Free Number Migrations: This requires coordination between the IT staff performing the cutovers, the carrier, and the business customer.
6. Cutover: During the cutover, the traffic will be migrated to the new carrier. A conference call with the project manager, IT staff, carrier, and business-unit customer should be scheduled so that everyone works together on the migration and testing. It is critical that the business-unit customer be engaged with this portion of the project. With this approach, there is joint accountability between IT and the business, which will hopefully avoid incident tickets the following day. However, keep in mind that many TFNs (toll-free numbers) have time of day and day of week routing, so you may not be able to test every scenario during the cutover.
7. Post-cutover: Keep an open line of communication between the members of the project team and business customer for the day following a cutover so that any issues can be quickly resolved. Testing time-of-day and day-of-week routing can also be performed during this window.
8. Decommission the routing, features, announcements, toll free numbers and TDM circuits from the legacy carrier. Lead times can be many weeks for these steps, and many must be performed in a specific order. Be careful with planning this step, especially if there are contractual deadlines to be met.
Note that these steps don't need to be completed for all toll free numbers before moving onto the next step. Numbers can be grouped into batches and run through this process as a batch. There will likely be batches of numbers going through the process simultaneously, all at different points in the process at any given point in time.
Hopefully this article brings to light some of the complexities involved in a migration of toll free numbers to SIP trunks with a new carrier. However, with a great project manager, the proper number of IT resources and business engagement, the project will be a success.
