The Nortel DMS-100 was released in 1979. There aren’t many pieces of technology that are 41 years old and still in active service, and yet we regularly run into people who still have DMS-100s active in their network.
And yet, very rarely do we find a telco with only a DMS-100. Most folks have purchased a replacement switch, but the migration from one to the other is incomplete. In this article we’ll be exploring why so many migrations end up half-done.
It seems odd at first glance – why would anyone buy a new class 5 switch, begin the process of replacing the old system, but give up before the end?
I’ve been involved (directly and as a supervisor) in many dozens of migrations, and actually, it’s not surprising at all. This situation occurs for two main reasons:
- Nearly all the benefits become available early in the migration process.
- Vendors are motivated to get their system into service, but they don’t care so much about decommissioning the old switch.
The benefits start early
Telcos are usually motivated to buy a new system because
- they want to deploy new features, which are not available on their legacy switch
- they are worried about the old system failing and not having any options.
The odd thing about switch replacements is that these desires are satisfied as soon as you move your first subscribers onto the new switch.
As soon as the new switch is in service, you have the ability to offer new features to anyone who wants them, and (heaven forbid) if your old system did start having hardware issues, you have your new system right there – so you can quickly move your subscribers to it. You have an insurance policy in place, which means that you’re less worried about the risk of disaster.
Vendors help you get started
The other big factor is that vendors often provide assistance through significant professional services engagements to help install and configure your new switch – and to get you to a place where you can migrate those first subscribers.
The vendors are keen to demonstrate that the system works well and was worth the investment – and your finance folks are motivated to put the system into service so they can start depreciating the asset.
Hurry up and wait
As a result of the above factors, there’s a lot of momentum pushing the migration forward to the point where the first subscribers are moved onto the new system, but after that things often stall.
- Your techs have other projects that have been postponed, and are keen to get back to them now that this milestone has been reached.
- Subscriber migrations can happen one-by-one, or in chunks based on access technology, and vendors often leave the telco to execute the migration without any active support.
- Even if you’re pretty aggressive in moving the majority of subscribers, there are usually a few subscribers with weird configurations, and it’s not easy to figure out how to migrate them.
As a result, it’s very common to end up with a shiny new VoIP switch running alongside the best class 5 switch available in 1979.
Sometimes this lasts a year or two, and sometimes it lasts a decade or more.
And to an extent, this is fine. You got the benefits by bringing the new switch online – does it really matter if you decommissioned the legacy switch?
Not that much no, but on the other hand…
- Think of all the power you could be saving if you turned off your DMS-100 (or EWSD or 5ESS or …).
- Wouldn’t it just feel good to finish the project and flip that breaker? You could put a pool table in the CO (in the newly freed up space and paid for by the power savings).
I want a pool table
If this describes your situation, if you have an old switch and want to finish moving lines and get that pool table, then reach out to us.
We’re not going to be able to do all the work for you, but let’s brainstorm together – maybe we can help get your subscriber lines pre-built in your Metaswitch, or maybe we can figure out how to provide that weird service that’s preventing you from moving those last few lines.
