Migrating to a unified communications infrastructure can be tricky for companies with lots of legacy equipment to deal with, including PBXs of both the TDM and IP varieties. Few are in position to simply rip out all of the old and install the new. More likely, it’ll be a phased migration, where old and new have to co-exist for some period of time.
Perhaps you’ve got TDM interfaces you need to support for some subset of the organization. Or maybe you’ve got an IP-PBX that provides specific services that certain segments of your organization can’t do without, at least not yet.
Many companies don’t want to or can’t afford to replace all their handsets at once, which can drive the need to retain some legacy PBX equipment. They may also have fax machines (don’t laugh) and concerns about E911 capabilities.
Or maybe they simply started with a UC solution such as Microsoft Lync for its instant messaging and presence capabilities and are now interested in migrating to enterprise voice, and realizing that’s going to be a little more complicated.
For all of these reasons and more, companies may find that migrating to a UC-based voice solution may be a process that takes years, not months. During that time, elements of their old environment have to coexist with the new.
Smooth the UC Migration with an SBC
The good news is there’s a tool available to help companies weather the migration storm: a session border controller. One of the functions of an SBC is to act as an intermediary between old and newer communications equipment.
SBCs provide transcoding of the protocols used by legacy and newer equipment and software. For example, an SBC can ensure an older fax machine or automatic call distributor can work with newer UC-based voice servers such as Lync.
That can be an important consideration, because many companies underestimate the number of analog devices still being used in their networks, all of which need to interoperate with the UC solution. Fax machines, common area phones, paging systems, and more all need to be accounted for to ensure a successful migration.
SBCs can also distribute calls on their own. When it recognizes a call is to a number supported by the legacy PBX, it performs the necessary transcoding to ensure it gets through. Ditto for calls destined for the UC voice server.
It’s likely that the mix of telecommunications services will likewise change as companies get deeper into their UC deployments, with SIP trunks replacing PSTN links. Here again, a good SBC is a crucial component, as it can provide interworking between various flavors of the SIP protocol used by different UC components and even carriers.
When used with SIP trunks, SBCs can also help provide redundancy and business continuity. The combination allows calls to be automatically rerouted in the event of a failure at any location. What’s more, an SBC can support 3G/4G wireless connections in the even of the primary trunk fails.
Using an SBC allows companies to embark on a more gradual migration to UC, enabling employees to continue using familiar systems while they learn the new ones.