On a day when Juniper Networks unveiled its biggest core router ever, Cisco felt the need to thump its own chest by releasing news that its own core router has reached a milestone in shipments.

Cisco has now shipped more than 900 CRS-1 routers to 85 service providers since it first hit the market in August 2004. Cisco says BT and Sprint are among the biggest service providers that have bought CRS-1s.

The CRS-1 comes in four-, eight- and 16-slot versions, with the largest capable of handling 1.2Tbps of traffic.

Cisco attributes the success of the router to video and other bandwidth-consuming IP traffic on networks around the world. For instance, Cisco says Internet video accounted for six times more IP traffic in 2006 than the total IP traffic that went across the U.S. Internet backbone in 2000.

Cisco also mentions that it believes global IP traffic, by 2011, will reach 26 exabytes - per month. An exabyte is a quintillion bytes - that is, it's a billion gigabytes.

That growth, of course, also benefits Juniper, which on the same day announced a 16-slot, 1.6Tbps core router. As my colleague Jim Duffy writes, it represents a big step beyond the previous high-end router, the T640, which provided just 640Gbps. (Also, see a slideshow on the T1600).

No doubt, Cisco at some point will release a router that goes beyond its current offerings as well, but right now Juniper appears to have acquired the leading edge. When's the CRS-2 due out?

Jeff Caruso is site editor at Network World.