W8SDZ@SIMTEL20.ARPA (Keith Petersen) (09/01/85)
Now available via anonymous FTP from SIMTEL20: Filename Type Bytes CRC Directory MICRO:<CPM.MODEM> X-PC.DOC.1 ASCII 127850 34DFH X-PC.DQC.2 BINARY 77056 CA2CH <-same, squeezed [Keith: which MAY be the same as TYMNET offers as:] Now available from your local Tymnet sales representative: X.PC PROTOCOL SPECIFICATIONS NPD-269 $3.00 This specification is published by McDonnell Douglas as a proposal to designers and implementors of personal computer communications software and packet network systems. It defines the formats and procedures at X.PC's packet and data line layers for Data Terminal Equipment (DTE) and Data Communications Equipment (DCE). Both switched virtual call and permanent virtualy call modes of operation are defined. This specification covers DTE and DCE operation when a packet switched network is accessed through a circuit switched or dedicated connection. It also includes the additional packet layer procedures necessary for two DTEs to communicate directly (i.e., without an intervening packet switched network) over dedicated or circuit switched connection. [Keith: this is the much-talked-about "error-free terminal protocol" now supported by TYMNET. It is an interesting alternative to MICROCOM's "MNP" protocol which you must buy a new modem to get (and which requires the "other end" to also have this type modem). If we could get BBN to support the X.PC protocol in the TAC software, we could have error-free sessions in spite of occasional noise on the phone lines.] --Keith
sunny@UCB-VAX.ARPA (09/05/85)
Please correct my mailing address to ...{ucbvax,decvax,ihnp4}!sun!l5!sunny
Sunny, KA6PPPhamilton@uiucuxc.Uiuc.ARPA (09/06/85)
just saw in Computerworld's "On Communications" that Hayes has
adopted X.PC over MNP...
the outfit i work for runs (in effect) a timesharing service
with users all over the country (plus a few overseas, too), who
get a variety of phone service quality problems. we experimented
a little with Microcom modems as a cure for line noise. however,
we've got a substantial investment in modems already (30+ dialins,
i think, plus 100's of users' equipment). i wanted to have a look
at the MNP protocol to consider implementing it in software on our
host(s) and possibly on PC's at the user end. Microcom's insistence
on cash up front before even a peek damped that idea.
then Tymnet came along... after 1 phone call* i got a PC disk with
an X.PC driver and an application (source) using it, plus a package of
protocol docs and stuff. a 2nd phone call elicited 2 more disks with
the sources for the driver.
i haven't decided yet if X.PC is the answer to our problems, but
i know i like dealing with the Tymnet people a lot more than Microcom.
wayne ({decvax,ucbvax}!pur-ee!uiucdcs!uiucuxc!)hamilton
* sorry, i don't have the phone number handy. also, i hear that they've
had so much response that they will probably have to change their
distribution methods.