1/31/2006 -- Chalk up another win for Cisco Systems Inc. and its Carrier Routing System (CRS) 1. Last week, Cisco announced that CRS-1 had been selected by Chinese telco giant Shanghai Telecom to expand its IP network and provide super PoPs for its high-speed core IP network.

There are a couple of important takeaways here, analysts say. For starters, Shanghai Telecom is the first Chinese telco to deploy CRS-1. More importantly, analysts say, Cisco's coup provides compelling proof that core capacity requirements are beginning to exceed the 1.2Tbps router densities of today.

"The major positives of Shanghai Telecom's announced intention to deploy the multichassis CRS-1 are a high-profile endorsement from an existing Cisco customer to use the CRS-1 as the platform to support expansion and expanded IP core capacity to meet rapidly growing service demand," says Glen Hunt, a senior analyst for carrier infrastructure with Current Analysis. "The announcement also shows that the demands for capacity exceed the 1.28 Terabits that is nominally supported in a single telco rack and the third area relates to ability for the service provider to collapse multiple layers of routers and/or edge aggregation platforms into a single multichassis CRS-1."

Increasingly, says Hunt, service provider core networks must support high subscriber densities and increased per-subscriber bandwidths. He cites a few examples, including that of AT&T (which uses Avici's TSR core router in multichassis configurations) as well as Juniper Networks Inc., which can accommodate up to 2.4Tbps of capacity in its T640/TX Matrix systems.

At the same time, Hunt points out, Cisco's CRS-1 hasn't yet turned two. In this respect, he argues, it still poses something of a risk for many adopters. "The major concerns related to the announcement relate to the following: The relatively new CRS-1 platform has not been proven by years of operational run time, especially in a multichassis configuration," he comments.

That's not all, of course. "[T]he ability to collapse multiple layers of routers into a single centralized router may in itself introduce new issues such as configuration and provisioning nuances," Hunt concludes. "[A]nd network migration from the existing Cisco gear to the CRS-1 will require considerable forethought given the large power and space requirements to house a full-blown CRS-1." -Stephen Swoyer