Re: UUCP question

John G. Thompson (jgt10@livingston.com)
Sun, 3 Nov 1996 21:46:01 -0800 (PST)

On Sun, 3 Nov 1996, Per Hedeland wrote:
>
> John G. Thompson wrote:
> >
> >On Fri, 1 Nov 1996, Krzysztof Adamski wrote:
> >> I know that I can use rlogin (been using it for over two years)
> >> what I wan't to know what is more efficient - rlogin or telnet to port 540
> >> for uucp.
> >
> >Actually, the most efficient is to use the portmaster daemon to make the
> >modem appear as a device on the uucp host.
> >
> >As far as rlogin or telnet, I don't there is a significant difference in
> >performance between the two. sigh.
>
> Though I've never used the PM for UUCP, let alone done any measuremnets,
> I think this is wrong - or rather a misunderstanding. Certainly
> "portmaster protocol" should be more efficient per se than telnet or
> rlogin (though I'd guess the difference is smaller for something like
> UUCP than for human interactive use), but the question was about "telnet
> to port 540", where a "uucp daemon" is presumably listening.
>
> This has got to be the most efficient alternative, as uucico will end up
> sitting directly at the other end of the TCP connection - whereas in the
> other cases (or for that matter telnet to the standard port 23), the
> bits go from the kernel to a user-level daemon (rlogind/in.pmd/telnetd),
> then back into the kernel through a pseudo-tty, and finally back out
> again to the user-level uucico - i.e. three context switches instead of
> one, and lots more code executed.

I'm unclear about the architecture of the "uucp deamon" on port 540. If
it is modified uucico program that listens to 540, accepts a connection
and then spawn a sub process, yes this would be the most efficient
configuration for the reasons you point out above.

If, howver, the uucp deamon is a proces that binds the 540 port and
allows a standard uucico process to work, then it will probably be close
to the efficiency of any of the above. In which case it probably a
choice made on what the user is more comfortable using, more than
anything else.

JGT

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