Path: utzoo!attcan!uunet!husc6!mailrus!ames!pasteur!ucbvax!ACC.ARPA!art
From: art@ACC.ARPA
Newsgroups: comp.protocols.tcp-ip
Subject: re: SLIP MTU "violation" - does anyone care?
Message-ID: <8810071249.AA14059@ucbvax.Berkeley.EDU>
Date: 3 Oct 88 17:20:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 26

>From: "Alan R. Hill" <ahill@CC5.BBN.COM>
>
>Rick,
>	I'll probably regret this but I have to ask why you have the
>impression that the IMP will not accept messages exceeding 1006 bytes?
>The X.25 limit is 1024.  The 1822 limit is 8063 bits and the DDN
>X.25 Standard service limit is 8056 bits or 1007 bytes.  Can you
>shed some light on where the 1006 byte number originated?
>
>Thanks,
>Alan

Alan,

I suspect that it dates back to old 1822 interfaces.  As you indicated,
for 1822, the limit is 1007 whole bytes.  But interfaces like the LH-DH/11
were 16-bit word oriented and therefore had a limit of 1006 bytes.
(IMP padding still occasionally nailed drivers not expecting more data
coming in than could be sent out)


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|	Art Berggreen		Advanced Computer Communications	|
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