Dear reader, I'm not updating these pages anymore. If you have tc or ip related questions, you can post them on the LARTC mailing list.

From help-files :
Special RSVP classifier
  The Resource Reservation Protocol (RSVP) permits end systems to
  request a minimum and maximum data flow rate for a connection; this
  is important for real time data such as streaming sound or video.
  Say Y here if you want to be able to classify outgoing packets based
  on their RSVP requests.
  This code is also available as a module called cls_rsvp.o ( = code
  which can be inserted in and removed from the running kernel
  whenever you want). If you want to compile it as a module, say M
  here and read Documentation/modules.txt