[mod.protocols.tcp-ip] Internet Multicasting for NETBIOS

braden@VENERA.ISI.EDU (Bob Braden) (09/20/86)

I would like to comment on the use of Internet multicasting for the
implementation of NETBIOS over the DoD protocol suite.

Both of the proposed protocols for implementing NETBIOS quite properly
restrict the use of NETBIOS broadcast packets to the same local network.
This restriction is necessary because the Internet architecure has not
provided a reasonable Internet-wide broadcast/multicast mechanism.

However,  I believe that this can be only a temporary restriction. 
There is a clear need to extend the Internet architecture to provide a
multicasting mechanism, and in fact the NETBIOS application is an
excellent example of the requirement for "distributed binding" which 
multicasting can provide. 

There is active work on the development and experimental deployment of a
Internet multicasting facility, as described in RFC 966 and RFC988.
Since (as we proudly proclaim) our work is characterized by trying out
something new before writing a standards document, the multicasting
extension to the Internet architecture described in these RFC's is not
yet in the "proposed standard" stage, although we are moving in that
direction.  Experimental implementations are now under development.

What are the implications for the NETBIOS protocol design effort?

**> Make sure your protocol is consistent with the proposed Internet
    multicasting facility, so that the local-net-only restriction on
    broadcasting can be removed from a NETBIOS implementation with
    minimal work when and if Internet multicasting is generally
    available.

At some point, the NETBIOS application could be a good demonstration of
the Internet multicasting facility.  The vendors developing NETBIOS
implementations for the DoD protocol suite are concerned with making a
product and selling it, rather than in protocol development.  However,
if NETBIOS is successful, perhaps customer interest in removing the
broadcast restriction will bring about a more active collaboration
between vendors and researchers interested in Internet multicasting.

Bob Braden