Phase 5 Upgrade Announcement

I am pleased to announce an upcoming upgrade of the T3 ANSnet/NSFnet
service. We are calling this the "Phase-5 upgrade" since it
represents the 5th major change to network infrastructure that we have
made since 1991. The infrastructure upgrade to the T3 network will
begin deployment on Friday 11/6 in Seattle and Denver, and will
continue at each T3 ENSS site and CNSS POP location during
pre-scheduled weekend maintenance windows through 12/18. The major
changes included in this upgrade are:

o Upgrade of all DS3/HSSI router serial interface adapters (T3
      CNSS and ENSS) to support full DS3 bandwidth. The router
      adapter bus interface cards will also be upgraded to double the
      packet switching rates per interface.

o The architecture for interconnection among CNSS routers at
      each MCI POP location will be upgraded from point-to-point
      links to a common FDDI ring.

o The T3 DSUs on each DS3 interface will replaced with a T3
      bandwidth manager (T3Plus BMX45) to accommodate T3 CNSS-CNSS
      circuits and a Larscom Access-T45 DSU on each end of a T3
      ENSS-CNSS circuit.

o New system software and microcode will be installed (already
      in progress) prior to the hardware deployment to support the
      increased adapter performance. Routing software has already
      been deployed to support the new CNSS FDDI ring architecture.

Deployment Schedule Summary