Path: utzoo!attcan!uunet!hsi!stevens
From: stevens@hsi.UUCP (Richard Stevens)
Newsgroups: comp.protocols.tcp-ip
Subject: UDP max datagram size ?
Keywords: UDP
Message-ID: <170@hsi86.hsi.UUCP>
Date: 21 Sep 88 20:14:04 GMT
Organization: Health Systems Intl., New Haven, CT
Lines: 18

Is there an agreed upon max datagram size for UDP packets ??
I couldn't find one in RFC 768.  In looking at the systems
I have access to, I see the original 4.3 BSD had a 9,000-byte
limit on transmit which was then reduced to 2,048 with the
4.3 network updates from Berkeley a few months back.  The PC
RT under AIX has a 512-byte limit, while the IBM mainframe
version (FAL) allows up to 2,048.  I'm aware of the performance
penalties once you exceed the network's MTU, but I was
wondering if there was a generally agreed upon maximum
(I'll guess there isn't).

As I recall from a few years ago, isn't this the reason the BSD
rwhod packets have a built in limit of information on up to 41-users.

	Richard Stevens
	Health Systems International, New Haven, CT
	   stevens@hsi.uu.net
           ... { uunet | yale } ! hsi ! stevens