BT was drawing a lot of attention at summer’s end as it completed negotiations with vendors, including Cisco Systems Inc. and Juniper Networks Inc., which it tapped as “preferred suppliers” for the 21st century network project. BT will be implementing one of the world’s most advanced converged services platforms anywhere to transport all services to over 20 million residential, business and wholesale customers in England.
To compete for BT’s business Cisco put together one of the largest bid teams it’s ever assembled, including members from every functional area of the company all the way up to CEO John Chambers. The company’s selection for contract negotiations marked a significant milestone in its efforts to demonstrate to carriers that it has adjusted its core technology for future requirements.
Over a year ago Cisco brought to market its CRS-1 core router platform and this year enhanced its legacy 12000 series core routers by adding the functionalities made possible by the Internetworking Operating System XR software that it introduced with the CRS-1. The IOS XR is a fully modular self-healing OS offering carrier-class performance and scalability as well as support for in-service upgrades and new features.
Cisco Systems’ 12000 series core routers
What Cisco set out to do with introduction of the IOS XR was to address the fact that simply upgrading routers to ever higher capacities would not take the industry where it wants to go as ever more complexity in service requirements enters the picture, notes Scott Yow, director for CRS-1 product management at Cisco. “A simple example occurs when you go from 100 to 1,000 routing sessions, which means you’ve reduced the processing power (of the software control plane) by one-tenth,” Yow says. “We realized we needed to tackle the problem of control plane scaling, and IOS XR was the result. IOS XR operates over distributed multiple control planes, each with processors running different subsets of hardware configurations but with the capability to communicate with all the other components.”
If the core router is to perform edge-like functions across all service categories it must support administrative separation of things like configuration files, user authentication, differentiation of access privileges and much else, Yow notes. “You have to be able to provide a very structured, hierarchical layering of services, customers and networks,” he says. One type of service that might be accessed by many customers must be easily blended with a dedicated service for a particular customer while maintaining all the QoS and user-policy parameters associated with each, he adds.
IPTV is an especially challenging addition to the service stream, not only because it requires rapid expansion of capacity but also because it stretches the multicasting capabilities MPLS was designed to support, Yow says. “The [IOS XR] platform provides the required multicasting support where each channel is provisioned once and managed centrally so that all are entering the service provider’s distribution domain through the same interface,” he explains.
“Or, to take the example of video on demand, the CSR-1 fabric allows you to do over 15 million VoD streams,” he says. “You can take a single channel feed in and replicate it out to millions of subscribers. That’s multiple orders of magnitude beyond the video scaling capabilities of earlier platforms.” The CSR-1 core router uses massively distributed multishelf architectures and 40gbps packet processors to achieve scaling capacity of up to 92tbps, he adds.
Some of these capabilities were confirmed recently in tests conducted by the European Advanced Network Technology Center, says EANTC managing director Carsten Rossenhovel. “We mixed IP version 4.0 and IP version 6.0 traffic at wire speeds of 1.2tbps totaling 15 million flows in five service classes,” Rossenhovel says. “We showed no congestion or latency for prioritized services. All packet loss and increased delay was confined to best-effort traffic, even when we sent massive bursts in best-effort mode.” Multicast was tested on the CSR-1 at 325gbps with 58 routing peers and showed zero loss, Rossenhovel adds.
For more on how core router sales are driving product technology advances, read "Core Routers Remain Central Players in Carrier Networks."
