NSFnet T3 Backbone Router

Who IBM & NSF (National Science Foundation)
What Experimental Router
When 1992
Why Internet backbone router

When the National Science Foundation's NSFnet backbone was upgraded from T1 (1.5 megabit) to T3 (45 megabit) links in the early 90s, there were no routers available that were capable of handling that much traffic, so IBM designed & built an experimental "NSS" ("Network Switching Subsystem") router to the NSF's specifications.

These systems were based on a Powerserver 930 first generation RS/6000 server, configured with special "RS960" interface boards. Each of the RS960 boards has two i960 CPUs, runs a stripped down AIX kernel, and is a fully functional router. Each "board" actually consists of two circuit boards: a base (router), and a second board which interfaces to a specific network interface (ethernet, FDDI, v.35, HSSI).

A NSFnet backbone node would consist of at least three NSS cabinets:

One "T3-B" (T3 Backbone) cabinet was configured with RS960 HSSI boards to talk to the T3 backbone lines.

One or more "T3-C" (T3 Customer) cabinets were configured with RS960 HSSI boards to talk to T3 lines for local sites.

One or more "T1-C" (T1 Customer) cabinets were configured with RS960 V.35 boards to talk to T1 lines for local sites.

Additionally, there was a Cisco router "T0-C" to talk to slower serial lines for local sites.

The NSS cabinets were connected together by RS960 FDDI boards.

This is one of the RS960 HSSI boards, which interfaces to the T3 NSFnet backbone lines. (Note: serial number 71. They didn't make a lot of these.)

These systems were shut down in the mid 90s because the rapidly expanding internet had outgrown the RS960's internal routing tables.