Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!spider.co.uk!nick
From: nick@spider.co.uk (Nick Felisiak)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Implementing TCP/IP outside of UNIX kernel?
Message-ID: <221.8904241901@brahma.cs.hw.ac.uk>
Date: 25 Apr 89 02:27:15 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 35
X-Unparsable-Date: Thu, 20 Apr 89 20:32:21 WET DST

In-Reply-To: Message from "David M. Balenson" of Mar 30, 89 at 9:31 am

> 
> 
> Is it possible to implement TCP/IP in a UNIX (Berkeley 4.{2,3}, SunOS{3,4})
> system OUTSIDE of the kernel?  I presume doing so would have a major impact
> on efficiency, but it might be much easier to program.  Does anyone know o
> any such TCP/IP implementations?  Thanks.
> 
> -David M. Balenson
>  Trusted Information Systems
>  (301) 854-5358
> 
> 


David,

At Spider we have written a "clean" version of the AT&T Streams package
(i.e no AT&T code but similar functionality), mainly as an aid to debugging
our streams software (TCP, X.25, ISO).  Using this, I run the whole "TCP"
stack (ip, arp, etc) in one process, and communicate from applications using
either UNIX IPC (msgget, msgsnd, etc), named pipes, or 'real' streams.

A standard raw ethernet driver is used to communicate with the outside world.

Performance is really not as bad as you might fear; measurements indicate
around 50% of the in-kernel system.

Makes portability really good, though!

Nick Felisiak				nick@spider.co.uk
Spider Systems, Edinburgh

+ 44 31 554 9424