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Another Point Of View (Round 2)
To date, I have read with interest this discussion. I insert that
the University of Texas at Austin has about 2000 dial in lines for student,
faculty and staff. This system is divided between analog delivery (the
lines installed originally), digital delivery (PCM E&M T1s) and digital
delivery (ISDN PRIs configured as E&M only and some PRIs as ISDN B channels
that can support both ISDN and PCM.) As the system expanded the local
telephone company (Southwestern Bell - SBC) reported interoffice trunking
problems from some central offices for just the PCM lines. This is a
capacity problem because of those pesky 15 hour phone calls (UT does not
limit users connection times). These trunks cause fast busy signals for
the users served by those central offices. Then we started an experiment
with ISDN and we discovered there were several central offices that did not
have full 64kbps B channels capability between offices only 56Kbps. SBC
now provides the digital delivery from the exchange of their choice to
allievate the trunking problem. We no longer are being served by a single
central office but are distributed at SBC's discretion.
Since the rotary is larger than the standard vendor switch can
support in its program ( there is apparently a 1024 limit on most
rotaries), SBC has decided to support the system with an intelligent rotary
that uses SS7 to distribute the calls to different switches based on the
type of line that delivers the service to our modem site. SBC has told us
the dial in system will be capable of serving all our needs at no
additional cost by Jan 1998 when the main Central Office switch is upgraded
and trunked to the other Central Offices with sufficient 64Kbps capacity to
support both PCM and ISDN B channel calls.
While the cost of the service is not the major issue facing UT, we
do find it interesting that alternative dial tone providers has driven SBC
to respond to our requests for expansion much more quickly. In Austin, we
have Time Warner and Metro Access as dial tone providers who have received
cetrificates to provide dial tone. The simple fact of notifying SBC to
route the main UCD rotary to a telephone number that is a rotary provided
by Time Warner has decreased response times for service repair and new
service.
As Internet service providers encounter the same kinds of limits on
service from the local exchange carriers, I can only guess at how each will
be handled. Our experience has been one plagued by success from a few
lines to two thousand lines. We continue to press to expand as a service
to our community of users and will no doubt encounter more interesting
situations with types of equipment and service delivery by the LEC.
This experience is not limited to ISDN but we feel is indicative of
the types of situations that will be encountered from the service provider
perspective. While most of the discussion has centered around the users
point of view, I think the service provider point of view is also important
when Internet access is expanded.
Thank you,
Wayne Wedemeyer
w.wedemeyer@utexas.edu
(512) 471-2454
FAX (512) 471-2449