bshafer@udenva.cair.du.edu (Bob Shafer) (06/17/89)
I am looking for software to do protocol file transfers over an X.25 connection between a Tandem and a MIPS. I imagine I can use something like xmodem or kermit (both are available on the Tandem). But I am wondering what (if anything) else might be available. Either public domain, shareware or commercial. Bob Shafer Colorado Alliance of Research Libraries Internet: bshafer@du.edu BITNET: BSHAFER@DUCAIR Usenet: ...ncar!dunike!bshafer
lars@salt.acc.com (Lars J Poulsen) (06/20/89)
In article <11841@duorion.cair.du.edu> bshafer@dunike.uucp (Bob Shafer, Colorado Alliance of Research Libraries) writes: >I am looking for software to do protocol file transfers over an X.25 >connection between a Tandem and a MIPS. > >I imagine I can use something like xmodem or kermit (both are available >on the Tandem). But I am wondering what (if anything) else might be >available. Either public domain, shareware or commercial. You don't say whether you are restricted to an X.29 virtual terminal, or you can use the full X.25 channel. In the latter case, I'd suggest hacking the TCP/IP FTP server and client to use the raw X.25 channel. Just make all RESETs into fatal errors. X.25 is described as a network layer protocol, but it really provides most of the services you would want from a session protocol. In particular, you have an 8-bit byte stream end-to-end with error correction, sequencing and flow control. So long as you do not see any RESETs (or CLEARs) you have guaranteed delivery. What more do you need for a channel to replace TCP ? Select an unused protocol number for the first byte of your user call data field, and if you feel you need a graceful close for the data path, use a Q-bit packet to indicate a clean end-of-file, and have the receiving end issue the CLEAR. This gives you a well documented protocol; mark the new MAN page as XFTP or similar and you're in business. / Lars Poulsen <lars@salt.acc.com> (800) 222-7308 or (805) 963-9431 ext 358 ACC Customer Service Affiliation stated for identification only My employer probably would not agree if he knew what I said !!