We've been talking a lot recently about session control platforms, which are also coming to be known as "layering" or "overlay" technologies, because they: a.) can control sessions across a multi-vendor environment via SIP; and b.) achieve this by creating a "layer" of SIP/session control over or around the legacy infrastructure.I happened to have mentioned in another forum--a VoiceCon newsletter--that Aastra was among the vendors that lacked this type of offering, and I happened to have been wrong about that. So Robyn Thompson and Tracy Venters of Aastra spent some time today explaining to me just how Clearspan, Aastra's major UC platform, handles this layering task.
Robyn explained that, since Clearspan is the Broadsoft carrier softswitch platform, it's always been SIP-based and session-focused, but this wasn't something that very many enterprises were looking for up until earlier this year, when Avaya made a big splash with these capabilities in its Aura platform. The timing also coincided with certain developments in the market--namely, a strong desire on the part of enterprises to save money and extend the life of their legacy systems--and the "layering" technology plays well to these developments.
Tracy pointed out the example of Aastra customer Texas A&M University, which has a legacy infrastructure supporting Centrex services as well as CPE from Nortel and others. Aastra is cutting over 3,000 users to Clearspan, and will eventually migrate all 45,000 end stations--but, "That migration's going to take a long time." Clearspan lets A&M "create a transport-agnostic applications layer" that can deliver new services to a broader user base, as well as doing things like keeping a centralized dial plan, without having to replace all the end stations today.
Robyn and Tracy showed me a slide that was very useful in understanding where the benefits of these "layering" systems come from. I've broken it in halves stacked on top of each other below, so that the labels on the pie charts are a little more legible:
This also lets the enterprise do a cap-and-grow approach; there haven't been a lot of expansions, given the economy, but when that starts happening again, you can build your new deployments off the overlay, rather than confronting a decision about how to do a lateral migration.
Moreover, just about all the vendors pushing the overlay technologies cite SIP trunking as a benefit that potentially could produce cost savings that would help pay for the new investment in the overlay. Also, consultants like Steve Leaden and others have pointed out that an overlay strategy is a particularly good way of keeping your options open if you're a big Nortel shop that isn't ready to make an enterprise-wide decision on what to do next, once Nortel goes away as a company.
Now, we've had plenty of articles, blogs, webinars and conference sessions warning you that realizing the cost savings of SIP trunking isn't a slam-dunk, and just getting SIP trunking everywhere is a challenge. But with a centralized architecture like you can build with Clearspan, Robyn Thompson points out, if you're able to get a SIP trunk to your carrier at your centralized location, you can backhaul others sites' traffic there and stand a better chance of making the SIP trunking benefits real.
For more on this topic, check out Jim Burton's No Jitter blog this week.
