RFC 1453 (rfc1453) - Page 3 of 10

A Comment on Packet Video Remote Conferencing and the Transport/Network Layers

RFC 1453             Comments on Video Conferencing           April 1993


   of remote conferencing.  Client/server applications including data
   base operations are equally important.  The ability to display
   noninteractive video and high-resolution graphics is necessary.

   As with most applications, security will eventually be an issue.  At
   the very least, there must be a mechanism to determine who can find
   out what about conference and who can join a conference.  This
   determination will be part of an upper-layer protocol.

      +--------------+ +--------+ +-----+ +------------+
      |Teleconference| |  File  | |Email| |   Domain   |
      |   (CCP)      | |Transfer| |     | |Name Service|
      +----+-------+-+ +-----+--+ +-+---+ +-----+------+
           |       |         |__  __|           |
           |       |            ||              |
     +-----+--+ +--+-----+    +-++-+       +----+---+
     |Network | | Packet |    | T  |       |    U   |
     | Voice  | | Video  |    | C  |       |    D   |
     |Protocol| |Protocol|    | P  |       |    P   |
     +---+----+ +--+-----+    +-+--+       +--+-----+
         |__     __|            |__         __|
            |   |                  |       |
          +-+---+--+             +-+-------+-+
          | Stream |             |     I     |
          |Protocol|             |     P     |
          +---+----+             +---+-------+
              |                      |
        +-----+----------------------+----+
        |IEEE_802.X,FDDI,DARTnet,ATOMIC...|
        +---------------------------------+

          Figure 1: The Connection Control Protocol Architecture

   The solutions must range in geography from single machines through
   LAN, CAN, MAN, WAN conferences, as well as in data content from PCs
   to high-end workstations.  Implicit in the scaling is the notion of
   product and application interoperability.

   Remote conferencing applications should take advantage of future
   network enhancements, as well as the functions provided by ATM, FDDI,
   and SMDS.  Doing so should provide function versus resource trade-
   offs such as cost versus error control and cost versus rate control.
   As a result, the transport layer should be able to provide the
   services offered by the data link layer.

   Most of the presentation on remote conferencing indicated a need for
   some degree of multicast functionality, ranging from the 1-to-n, with
   conference membership completely known, to conferences for which



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