1/15/2008 -- What's happening in the beefy carrier switching space? Change -- and lots of it. Consider ATM -- long the workhorse of the carrier switching backhaul -- which (after a storied career) finally seems to be on the way out.

It's been a long time coming. For a decade or more now, multi-service WAN switches have formed the bread-and-butter core of the carrier infrastructure. In this regard, they've been surprisingly resilient -- although even the most resilient technologies have their breaking points.

"ATM-based core and edge switches have satisfied nearly every challenge thrown at them by service providers," said Glen Hunt, a principal analyst for carrier infrastructure with consultancy Current Analysis. "They have been deployed to address everything from low-speed to high-speed services, special protocols, high availability, high performance, security and manageability complete with OAM, NMS and OSS/BSS support."

Over the years, Hunt noted, ATM switches have been deployed in support of broadband, mobile backhaul, multi-service edge and IP/MPLS core network applications. And while the bottom hasn't yet fallen out of the ATM switching market, decline seems inevitable.

"While this is still a sizeable market segment for large and small vendors alike, we have begun to see the decline in revenues and interest in this once innovative and very capable class of products," Hunt said. "The rapid decay of this market has been held off due to continued build-out of ATM-based DSL and mobile backhaul networks to keep up with demand, but 2008 marks a turning point where newer-generation Ethernet switches and routers will begin to supplant the older generation."

There's more. Because while change seems to be a constant in the carrier Ethernet segment, change -- as a disruptive force, at any event -- is disproportionately associated with a specific (and highly commoditized) technology: namely, Ethernet. One upshot of Ethernet's ascendance is a dramatic lowering of the bar, cost-wise, for carrier-grade multi-service switching technology.

"Carrier-grade Ethernet has changed the rules of the game and made significant inroads into what was traditionally the domain of the gold-plated interface modules of the past," Hunt continued. "Carrier Ethernet addresses the cost, QoS and reliability of traditional port technologies at a fraction of the cost of its predecessors."

As a result, according to Hunt, carrier-grade Ethernet is tremendously popular among vendors and service providers alike.

"Most equipment providers have stepped up to deliver solid carrier Ethernet capabilities on their next-generation access, edge and core platforms," Hunt said. "New classes of products are being deployed that have been built for Ethernet-centric applications and have the carrier-grade attributes needed to deliver a broad range of services at much lower price points than previously possible." --Stephen Swoyer