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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
          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
  (512) 471-2454
  FAX (512) 471-2449