value of co-location

Sat Jan 20 04:35:54 UTC 1996

The reasons for co-location that have been mentioned so far include...

 - zero-mile circuits
 - a hardened location for equipment
 - to establish a local presence rather than building out one's own space.
 - skepticism about the value of the fast packet services; the skepticism
   has several flavors:
    - reduced bandwidth due to protocol overhead
    - less reliability than a shared FDDI
    - performance of ATM switches compared to FDDI switches

'Zero-mile circuit' isn't clear to me because, regardless of the technology
used for the NAP, it's still necessary to purchase a circuit from your site
to the NAP.  The circuit is either included in the price of the fast packet
service or purchased separately as a leased line to the co-location site.

The next two points, 'hardened location' and 'establish a local presence,'
make sense.  If you do not have a presence in the city where the NAP is
located, co-location serves that purpose.

The various statements made concerning the value of the fast packet services
are familiar arguments.  I'd like to point out that CERFnet uses SMDS, the
Northwest NAP (NIX) uses Frame Relay, and the San Francisco and Chicago ATM
NAPs are carrying significant amounts of traffic.  The Chicago NAP is
experiencing peak traffic of nearly 80 Mbps.  What is needed to move the
debate forward are objective performance criteria and measurements, and I
look forward to the work of the Benchmarking Methodology Working Group to
provide that criteria.

George Clapp
voice: 201-829-4610
fax:   201-829-2504
page:  800-980-1298
email: clapp at bellcore.com