PPS Modem Pool - Pilot Study
Since the
beginning of the project, the University of Pittsburgh and
Carnegie-Mellon University have gratiously provided teachers and staff of
the Pittsburgh Public Schools (PPS) with access to their modem pools
for home use. Common Knowledge: Pittsburgh wants to provide all PPS
students and teachers with 24 hours/365 days full Internet access.
Common Knowledge: Pittsburgh and PPS are interested in investigating the
option of running a modem pool that would expand access to:
- students after school hours and
- non-CK:P schools, using dialup, during work hours.
Towards this end a series of meetings occurred between CK:P and PPS
technical staff to develop a viable model. The following two pilots are the
result of these discussions.
Modem Pool Pilots
Pilot One to be accomplished by August 1. The goal of
this pilot is to provide non-CK:P schools with LAN access to the net over
voice grade phone lines.
To do this, it requires a multiport asynchronous interface board in the
existing NetBlazer ST, 8 new phone lines and 8 new v.34 bis 28,800 baud
modems. (The pilot does not specifically require 8 modems and lines. It
could be a smaller number, depending on the number of remote sites to be
supported.)
Pilot Two to be accomplished by September 1. The goal is
to provide both dialup and SLIP access from individual machines with
modems from school or home. Users will authenticate at the router
using the CK:P Kerboros server.
A significant aspect of this pilot will be existing phone lines
and modems that are used to access the district's administrative
network. At present, from 6:00 AM to 6:00 PM these lines are used for
administrative access. In the pilot, they will still be used for that
purpose, but if the demand is low, 8 of the existing 80 lines will be able
to access the Internet. From 6:00 PM to 6:00 AM the 8 lines will be used
exclusively for Internet access.
To do this, it requires a new router that can allow multiple protocols
(XNS and IP). The Cisco 2511 is being considered.
- Note 1: While it is desirable to evaluate whether the XNS terminal
access (the existing PPS protocol) can be accomplished in a new router,
the baseline notion of doing inverse terminal service to access RS-232
ports on a Data General terminal server only requires that the new
terminal server be capable of TCP/IP services, and be capable of
cross-connecting its own serial lines together. All candidates for this
function, whether Cisco, Annex, NetBlazer, Livingston Portmaster, or the
new kid on the block, need to be evaluated for the inverse terminal
service from both the LAN and from serial lines, and for the feature set
they have for authentication and access controls.
- Note 2: The inverse scheme, if workable, would allow both mainframe
and Internet access at all hours. It may be that there can be options with
on authentication server to restrict either which individuals have access
or how many individuals, in a given class, have access at different times
of the day.
Next Steps
The first pilot, if successful will allow access to schools that are
beginning to put their LAN topology in place. The next step would be for
these schools to use higher speed data transmission that is supported
using other routers at the central site.
If the second pilot is successful, it is the goal of this working group to
make all 80 lines available in the evening for Internet access.
We will revise this document as the pilots are put in place.