Re: Comparisons

[hes@unity.ncsu.edu]

  John Harris writes:
  > ...
  >> 28.8 internet connections are not compressed. S o you need an ISDN
  >> connection to your ISP to get the speeeeeed...
  >> 
  >Um, beg pardon?  If your and your provider both have 28.8 modems with 
  >compression enabled, then you have compressed connections.  I know I do 
  >with my own ppp connection between home and work on a pair of MultiTech 
  >ZDXs....
  
    Yes, on-the-fly compression has been available in modems (built-in)
  for many years (MNP was one of the pioneers.)  It is effective (although
  it was correctly pointed out that its effectiveness depends on the
  material being sent) but one drawback is that it worsens latency.
  
    In principle, whatever compression methods are used with modems could
  also be used with ISDN, giving identical speed-up results - but now from
  a 64 (or 128) kbs base instead of a 28.8 kbps base.  As before, latency
  would be degraded - but at higher bit rates the degradation may be less 
  noticeable.
  -- 
  --henry schaffer
  hes@ncsu.edu