[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: cost of residential ISDN (fwd)

  more on the issue of blockage (or nonblockage) on ISDN...
  ---------- Forwarded message ----------
  Date: Tue, 16 Jan 96 19:08 EST
  From: Marty Tennant <marty@sccoast.net>
  To: Martin Weiss <mbw@lis.pitt.edu>
  Cc: love@essential.org
  Subject: Re: cost of residential ISDN
  >On Tue, 16 Jan 1996, Marty Tennant wrote:
  >> Martin, I'm not sure what you mean.  Could you elaborate?
  >> Marty
  >> >On Mon, 15 Jan 1996, Marty Tennant wrote:
  >> >> So that means that, within a 10,000 subscriber line capacity central
  >> >> 5,000 folks could be talking to 5,000 other folks on the same switch
  at the
  >> >> same time.  No increase in costs would result (maybe more power
  >> >> and the capacity would be there from the time of installation.
  >> >
  >> >and congestion costs.
  >> >
  >Congestion costs are social costs that a user imposes on others based on 
  >their usage.  For example, if I am a heavy user and tie up the switching 
  >fabric, then I can cause blockage of other users.  The congestion cost is 
  >the cost of unrealized usage.
  >Jeff Mackie-Mason and Hal Varian have written an excellent intro paper on 
  >this theory.  It is available from their web site as well as in the IEEE 
  >Journal on Selected Areas in Communication (September or October 1995).
  >Martin Weiss
  >Telecommunications Program
  >University of Pittsburgh
  Martin, this holds true in a network that has the potential for bottlenecks.
  Unless contradicted by someone with direct technical knowledge, I contend
  that current ISDN switches, from Nortel, AT&T or whoever, are non-blocking
  switches.  This does not allow for blocking within the immediate switch.
  If you are speaking about interoffice trunking of ISDN calls, then there
  *is* a potential for heavy users tying up the connections between the
  central offices.  In most large cities, there are sufficient fiber optic
  connections between all CO's that this isn't a problem.
  So I'm not sure your congestion costs are a real problem in the real world.