Subject: Re: Telnet from MacBSD over SLIP
To: Allen Briggs <>
From: Bruce A. Mah <bmah@tenet.ICSI.Berkeley.EDU>
List: macbsd-general
Date: 01/28/1994 09:10:56
Allen Briggs writes:

>> telnet: setsockopt (IP_TOS) (ignored): Invalid argument
>> Does anyone know that these mean?  they don't seem to have any effect.

> I think that's just 'cause the kernel is well ahead of user-land, and
> the programs are attempting to set an option that no longer is available
> in the networking system.

Well, I think it's kind of the other way around.  TOS == "type of
service", a way for IP clients to set what kind of network service
they want/need (i.e. "low delay", "high bandwidth"...a qualitative
measure).  Check RFC 791 for more details.

Newer versions of TCP/IP clients (e.g. the ones in BSDI, and
apparently NetBSD) will set the right bits in the IP header to
indicate their TOS preferences, but not all IP implementations will
support it.