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Re: IP: Pac Bell says Net use may collapse phone system

  At 10:44 AM 10/30/96 -0500, Dave Reid wrote:
  >Here's the point I've being trying to make the problem on non-answered calls
  >is not interswitch, it's intraswitch. The increased load is placed directly on
  >the portion of the switching fabric that is least able to handle it.
  >And the by the way the processing load for uncompleted call is virtually the
  >same as a completed call. (If one was to really slice the hair thin it is
  >true that an interswitch uncompleted call also consumes some trunking
  Well we are splitting hairs here, but it's not a major issue anyway.  When
  a busy signal is received, the caller almost always disconnects promptly.
  They don't sit around ruminating on the busy tone, even while using an intra-
  switch talk path to listen to it.
  Dave, since you're quite familiar with the DMS100, can you provide us with 
  more details about its latest revs?  I know how the traditional line 
  concentration module provides ten 64-line drawers with six 30-channel
  loops, for a total of 180 in use at once when fully equipped.  Does the
  current LCMI have the same limit?  What about the S/DMS variant -- is that
  real or just marketing?  (I was involved in some DMS installations around
  1985, but haven't put in any recent ones.)  Also, does the ISDN BRI line
  card take one slot in the drawer?  In that case, could (in theory) a single
  LCM carry 1280 B Channels?  (I know it would be a bad idea!)
  Also, is this affected by the "supernetwork" in the DMS Supernode?  Do the
  LCMIs still use "DS-30" links, or is there a fatter link (say, 256, but I
  don't recall the details) which provides more capacity?
  The 5E seems to have a somewhat lower design capacity on its analog ports,
  if you completely fill the modules.  (Of course much or most of the cost of
  the line modules is in line cards and the shelves/drawers that support them, so 
  it's not as if you have idle lines in order to run higher traffic.)  If only 
  the DMS had such good BRI features....
  Fred R. Goldstein      fgoldstein@bbn.com  
  BBN Corp.              Cambridge MA  USA    +1 617 873 3850