bill@ftp.COM (Bill Lampman) (10/28/88)
In article <322@cocktrice.UUCP>, mdm@cocktrice.UUCP (Mike Mitchell) writes: > I have recently acquired a copy of the book "UNIX Programming on the > 80286/80386" by Alan Deikman, and this book raises some questions for > me. [other stuff deleted] > Is there a good source of documentation on how one deals with the line > discipline from the device driver level? I have looked at other information > including Bach's book and nothing covers this aspect with any kind of > depth. I would also like any information that is available on line disciplines; I've been poking through the serial line drivers in the Xenix kernel using a debugger and it seems like SCO Xenix only supports one line discipline. Am I missing something obvious ? Thanks to all of you who responded to my question about SLIP, those answers have given me the correct solution, ie. line disciplines, now all I need to do is implement it. While I'm on the subject, why is there is SLIP code for BSD 4.3, 4.2 and SUN OS but none for SysV ? Is it that AT&T wants everyone to use UUCP so that their phone bills will pay for future development projects ? Bill -- ------------------------------------------------------------------------------ Bill Lampman @ FTP Software UUCP: ...harvard!ftp!bill ARPA: bill@ftp.com ...sometimes the songs that we hear are just songs of our own...
guy@auspex.UUCP (Guy Harris) (10/28/88)
>While I'm on the subject, why is there is SLIP code for BSD 4.3, 4.2 and >SUN OS but none for SysV ? Because there's standard IP in 4.3BSD, 4.2BSD, and SunOS, but none for System V. You have to get networking implementations from a third party, or from your vendor if they've added it to System V. As I remember, at least one of the third-party implementations - the Convergent/Lachman one for S5R3 - *does* include SLIP.... >Is it that AT&T wants everyone to use UUCP so that their phone bills >will pay for future development projects ? Oh? Are you asserting that you can send things over dial-up SLIP (e.g., running SMTP over TCP over IP) faster than you can over dial-up UUCP? If not, your phone bills aren't going to go down....
davidsen@steinmetz.ge.com (William E. Davidsen Jr) (10/29/88)
In article <391@ftp.COM> bill@ftp.COM (Bill Lampman) writes: | While I'm on the subject, why is there is SLIP code for BSD 4.3, 4.2 and | SUN OS but none for SysV ? Is it that AT&T wants everyone to use UUCP so that | their phone bills will pay for future development projects ? Could you post your performance numbers for uucp and SLIP? The packet overhead is about the same, and I wouldn't expect mush diference in speed. I see about 219-222 cps on a 2400 baud line, so there's not much to gain unless you go synchronous. You can get some very bad performance out of uucp if you "detune" it to use less than seven buffers, but in a reasonable configuration it works very well. If you have really big line delays another protocol for file transfer is desirable, neither uucp or slip. Perhaps zmodem? -- bill davidsen (wedu@ge-crd.arpa) {uunet | philabs}!steinmetz!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me
allbery@ncoast.UUCP (Brandon S. Allbery) (11/04/88)
As quoted from <391@ftp.COM> by bill@ftp.COM (Bill Lampman): +--------------- | While I'm on the subject, why is there is SLIP code for BSD 4.3, 4.2 and | SUN OS but none for SysV ? Is it that AT&T wants everyone to use UUCP so that | their phone bills will pay for future development projects ? +--------------- In these post-divestiture days such a scheme is impossible. The reason there's no SLIP code for System V is that System V doesn't support IP (yet). SLIP is layered onto IP the way TCP is layered onto IP; they are both device-level interfaces to the IP protocol code. As for the STREAMS-based networking, perhaps the delay is for AT&T STREAMS-based ttys so SLIP modules can be pushed instead of using line disciplines... but that's probably not of interest to you unless your Xenix is really UNIX V.3.2. (Earlier Xenixes don't have IP.) ++Brandon -- Brandon S. Allbery, comp.sources.misc moderator and one admin of ncoast PA UN*X uunet!hal.cwru.edu!ncoast!allbery <PREFERRED!> ncoast!allbery@hal.cwru.edu allberyb@skybridge.sdi.cwru.edu <ALSO> allbery@uunet.uu.net comp.sources.misc is moving off ncoast -- please do NOT send submissions direct Send comp.sources.misc submissions to comp-sources-misc@<backbone>.
john@jetson.UPMA.MD.US (John Owens) (11/08/88)
Just to correct a slight misconception (or maybe hasty fingers):
> SLIP is layered onto IP the way TCP is layered onto IP;
Actually, IP is layered onto SLIP the way IP is layered onto an
Ethernet driver.
--
John Owens john@jetson.UPMA.MD.US uunet!jetson!john
+1 301 249 6000 john%jetson.uucp@uunet.uu.net