Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!necntc!dandelion!ulowell!apollo!mishkin
From: mishkin@apollo.uucp (Nathaniel Mishkin)
Newsgroups: comp.sys.apollo
Subject: Re: Native ethernet for Apollos
Message-ID: <3a79b388.c366@apollo.uucp>
Date: 24 Feb 88 14:12:00 GMT
References: <8242@eddie.MIT.EDU>
Reply-To: mishkin@apollo.UUCP (Nathaniel Mishkin)
Organization: Apollo Computer, Chelmsford, MA
Lines: 33
Keywords: ethernet, ringnet, gateway

In article <8242@eddie.MIT.EDU> rich@eddie.MIT.EDU (Richard Caloggero) writes:
>My question is
>this: what are the advantages/disadvantages of replacing our domain
>ringnet with ethernet.  If we go with our current plan of using one of
>our 3000s as a gateway to the ethernet on which there exists only one
>host, the fx8, is it probable that this might become our bottleneck in
>the future, especially since we don't have the resources to dedicate
>one Apollo exclusively to the task of being a server; they will all be
>used interactively?  Also, is domain/os, since it is more Unix-like,
>more comfortable running in a native ethernet environment?

Using an Apollo attached to an Ethernet is virtually no different using
one attached to an Apollo token ring.  It just works.  DOMAIN/OS has
no bearing on the matter, because it's worked for some time.  The only
differences arise from different intrinsic properties -- e.g. on an ring
net, a sender of a message can sometimes get information back about the
state of the receiver in the same time it takes to send the message;
this isn't the case on an Ethernet.  The result is that there are some
cases on a ring net where a sender can immediately determine that some
remote machine is (say) down, whereas on an Ethernet, the sender has
to go through some software-driven timeout/retry scheme.

In an installation that already has machines on an Ethernet, putting
your Apollos on the Ethernet can be only a plus.  Apollos on a ring are
guaranteed to have to go through at least one gateway to get to your
other machines.  Apollos on an Ethernet will be able to talk to other
machines on the same Ethernet directly.


-- 
                    -- Nat Mishkin
                       Apollo Computer Inc.
                       Chelmsford, MA
                       {decvax,mit-eddie,umix}!apollo!mishkin