Path: utzoo!utgpu!watmath!att!ucbvax!TGV.COM!adelman
From: adelman@TGV.COM (Kenneth Adelman)
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  Dbridge and Multinet
Message-ID: <890830122108.20200086@TGV.COM>
Date: 30 Aug 89 19:21:21 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Adelman@TGV.COM (Kenneth Adelman)
Organization: The Internet
Lines: 37

> DBridge sounds probably refers to one of the options that you can get with
> the VMS TCP/IP from The Wollongong Group.  It permits IP to operate over
> DECNet, rather than permitting DECNet to operate over IP; my last
> indication was that that their VMS product is not yet shipped with
> the latter capability.

    One comment about DBRIDGE.	It is correctly credited to Van
Jacobson and Craig Leres of the Lawrence Berkeley Laboratory.  You can
FTP sources to it from FTP.EE.LBL.GOV in their anonymous directory.

    DBRIDGE is an excellent example of how a customer can add a
customer-specific transport to either MultiNet or WINS/TCP using the
'rp0' interface.

> Multinet is the name of another VMS TCP/IP, developed at SRI International,
> and I believe still distributed by them to some lucky folks, but perhaps
> not, since it (also?) is sold by TGV, an SRI "spinoff".  I believe that
> they, too, can do DECNet over TCP/IP but are not yet shipping IP or
> DECNet.

    MultiNet is distributed principally by TGV, SRI, and Excelan.
MultiNet implements DECnet over IP, and IP over DECnet in two
different ways:

    1) Using DBRIDGE to allow customers to make connections to
       WINS/TCP sites.	The disadvantage of using DBRIDGE is that
       there is a VMS process which must be brought into context once
       for each packet which comes or goes over the DECnet.

    2) Using the ALTSTART interface into the VMS NETDRIVER.  This
       allows us to pass the IP packets to DECnet without having a VMS
       process in the way.  Although the encapsulation is not
       compatible with DBRIDGE, the performance is much greater and
       the system overhead much less.

						Kenneth Adelman
						TGV, Incorporated