Inter-exchange media types

["Jon 'tex' Boone" <tex () isc upenn edu>]

Folks,

  I know that many of the Inter-exchange points are using FDDI and
  switched FDDI for inter-exchange in lieu (or anticipation) of ATM.

  I am wondering if anyone has considered using switched 100baseFx or
  similar technology for an inter-exchange.  Given the relative
  newness of these interfaces on high-end routers I would not be
  suprised to hear that no one is using them right now.  But has
  anyone looked into using them?  Is there a good reason to prefer
  switched FDDI over 100baseFx (which can do full-duplex 100 Mb/s
  switched)? 

  <tex () isc upenn edu>