Xchat -- miscellaneous information

* The "extraNet" resource

  To extend xchat's view of the Internet with other
  sites, one may define the resource called "extraNet".

	XChat.extraNet : machine.far.away.edu

  will send the usual messages to that particular
  machine.

  As a result the remote xchat processes will add
  you to their User List and respond their identity
  to your xchat process.

  Multiple machines may be specified separated with
  `:'. In stead of machine names, one may specify
  an Internet broadcast address, however, usually
  packages addressed using IP broadcast addresses
  are blocked by Internet routers when they come
  from outside the local network.

* bcmon, xsman -- what's going on??

  When starting xchat, it will send a UDP/IP message
  to each address in the "baseNet" and "extraNet"
  resources, and if there are any xchat's alive it
  will get response. This will update the User Lists
  of all running xchat's.

  Xsman, the Xchat Session Manager, serves all the
  communications required for an Xchat session via
  TCP/IP connections. When xsman serves a Discussion
  or Bulletin it will `advertise' the same way as
  xchat does advertise your identity. As a result
  the title of the discussion or bulletin will
  appear in the appropriate list.

  Xsman is invoked on creating a session and runs
  on the host where the ancestor runs xchat. It
  dies when the session lost all its participants
  with the exception for discussions: it will wait
  for 5 minutes before ending its service.

  Bcmon, the BroadCast monitor, is serving all xchat's
  and xsman processes running on one single host.
  Xchat and xsman use one public UDP/IP port.
  Only one single process may claim the unique UDP
  port. Bcmon claims the port and multiplexes all
  incoming messages to whatever xchat's or xsman
  processes connected. When the last process dis-
  connects, bcmon will terminate.

  If bcmon dies unexpected, all running xchat and
  xsman processes will recover. Using a random time
  to wait, only one process will succeed in starting
  a new bcmon, others will connect a moment later.
