USENIX Board Studies UUCP

[Jon Zeeff]

In article <37014 at apple.Apple.COM> fair at Apple.COM (Erik E. Fair) writes:
>In the referenced article, zeeff at b-tech.ann-arbor.mi.us (Jon Zeeff) writes:
>>
>>All we really need is for vendors to fix the larger packet sizes 
>>code in uucp so that acks will fit in small reverse channels.  Telebit 
>
>A UUCP ACK is 6 bytes. My understanding is that the telebit "reverse
>channel" allows for 11 bytes. Why doesn't it work the way you expect?
>Could it be the small standard window size (2 to 3 packets), or the
>small outbound packet size (64 bytes)? (rhetorical questions, don't

It's the small packet size.  11 bytes how often?  On a percentage 
basis: 6/64 ~= 10% which is too big for a trailblazer or HST reverse 
channel.  6/512 = 1% which should fit.  

>There is no "bug" here; UUCP g-protocol was not engineered to use these
>half-duplex pseudo-full-duplex modems. If you can't fix UUCP, you fix

Whether it was engineered for it or not, uucp using 'g' can support 
larger packet sizes which, with a fixed ack size, are what these 
modems need to avoid reversing the channel.  If fact, large packets 
even work on some versions of uucp (I've tried it).  

Telebit did a smart thing and is being rewarded for it.  It doesn't mean
that other solutions should be neglected.

-- 
Jon Zeeff    		<zeeff at b-tech.ann-arbor.mi.us>
Branch Technology 	<zeeff at b-tech.mi.org>