kipnis@janus.Berkeley.EDU (Gary Kipnis) (10/26/89)
Recently I bought Everex 2400 Baud MNP Level 5 Modem, and the manual said that if the other line supports MNP Level 5 protocol and if I have compression turned on, I can actually achieve higher transfer rates by increasing the transfer speed between computer and modem to say 4800 baud. The two questions are: How do I find out if the other line supports MNP Level 5 protocol and if it does how do I utilize this "speed up" thank you gary P.S. I am sure this is a new topic, so please post, since it should be of an interest to everyone
madd@world.std.com (jim frost) (10/26/89)
In article <32171@ucbvax.BERKELEY.EDU> kipnis@janus.Berkeley.EDU (Gary Kipnis) writes: |Recently I bought Everex 2400 Baud MNP Level 5 Modem, and the manual said |that if the other line supports MNP Level 5 protocol and if I have compression |turned on, I can actually achieve higher transfer rates by increasing |the transfer speed between computer and modem to say 4800 baud. This speedup won't be to 4800 baud, although we got noticable improvements -- something like 3500 baud -- for text. There will probably be a slight slowdown with compression if you are transferring binary, but the reliability of MNP makes up for it; you will not loose many packets when up/downloading software. |The two questions are: |How do I find out if the other line supports MNP Level 5 protocol and if |it does how do I utilize this "speed up" If you have your end enabled, it will respond with something like: CONNECT 2400/REL I'm not sure what the response is if you're not in verbose mode. I could go look it up but it's pretty immaterial. The only thing you should have to do to utilize the speedup is use the modem. There are some caveats. If one end or the other is talking to the modem at (say) 2400 baud, throughput WILL NOT exceed 2400 baud. Most MNP modems allow the host to talk to them at higher speeds (we use 9600 baud between the host and the modem for our public dial-in lines and the speedup from home is obvious and quite impressive). Even if throughput isn't higher than 2400 baud, the reliability is wonderful. jim frost software tool & die madd@std.com
mr@cica.cica.indiana.edu (Michael REGOLI) (10/27/89)
kipnis@janus.Berkeley.EDU (Gary Kipnis) writes: >Recently I bought Everex 2400 Baud MNP Level 5 Modem, and the manual said >that if the other line supports MNP Level 5 protocol and if I have compression >turned on, I can actually achieve higher transfer rates by increasing >the transfer speed between computer and modem to say 4800 baud. >The two questions are: >How do I find out if the other line supports MNP Level 5 protocol and if >it does how do I utilize this "speed up" Gary, if you receive the "CONNECT 2400/REL" message, you have established a RELiable MNP5 link with the host. If you see the plain "CONNECT 2400" you have not. (Assuming the modem is Hayes-compatible, issue the command "AT\V1" to enable extended result codes, otherwise you're liable to see the short version, "23".) To utilize the "speed up," you need access to a file transfer program that utilizes error-correcting modems. In other words, if you use Kermit or Xmodem, for instance, that *already* use built-in error correction mechanisms, you WILL NOT notice any improvement in throughput since the software *and* the modem are producing redundant error-checking overhead. (File transfer protocols such as Ymodem-G and Imodem that are part of ProComm, for instance, do *not* use error correction schemes and are therefore appropriate for use with error-correcting modems.) If anyone has any pointers to non-error correcting software running under Un*x, I'd appreciate knowing! -- michael regoli mr@cica.indiana.edu regoli@iubacs.bitnet ...rutgers!iuvax!cica!mr
davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr) (10/27/89)
In article <186@cica.cica.indiana.edu>, mr@cica.cica.indiana.edu (Michael REGOLI) writes: | Gary, if you receive the "CONNECT 2400/REL" message, you have | established a RELiable MNP5 link with the host. Is this just with Everex? When I connect my MultiTechs to other systems I get the 2400/REL message with ANY MNP level 3 or higher. There is nothing which tells me the level. Do the Everex modems say something else for MNP3 or 4? -- bill davidsen (davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen) "The world is filled with fools. They blindly follow their so-called 'reason' in the face of the church and common sense. Any fool can see that the world is flat!" - anon
madd@world.std.com (jim frost) (10/27/89)
In article <186@cica.cica.indiana.edu> mr@cica.cica.indiana.edu (Michael REGOLI) writes: |kipnis@janus.Berkeley.EDU (Gary Kipnis) writes: |>How do I find out if the other line supports MNP Level 5 protocol | |Gary, if you receive the "CONNECT 2400/REL" message, you have |established a RELiable MNP5 link with the host. This is only partially right. You will have connected with a modem that supports some level of MNP, not necessarily level 5. I've seen several modems which have level 4 and Microcom has support for (at least) level 6 and level 9, since I've seen both on their 9600bps modems. MNP-compatible modems have a handshake which determines which level they will use, so all of this is fairly transparent to the user except for speed and reliability improvements. jim frost software tool & die "The World" Public Access Unix for the '90s madd@std.com +1 617-739-WRLD 24hrs {3,12,24}00bps
prc@erbe.se (Robert Claeson) (10/27/89)
In article <32171@ucbvax.BERKELEY.EDU> kipnis@janus.Berkeley.EDU (Gary Kipnis) writes: >Recently I bought Everex 2400 Baud MNP Level 5 Modem, and the manual said >that if the other line supports MNP Level 5 protocol and if I have compression >turned on, I can actually achieve higher transfer rates by increasing >the transfer speed between computer and modem to say 4800 baud. >The two questions are: >How do I find out if the other line supports MNP Level 5 protocol and if >it does how do I utilize this "speed up" We have Microcom AX/2424c's with MNP 5. The modems are set to use 9600bps on the serial line, regardless of what the actual line speed between the two modems are. Thus, the modems agree upon what protocol and what speed to use and notifies the use in the "CONNECT" message. CONNECT 2400/REL, for example, tells me that "my" modem found a V22bis modem with some kind of MNP at the other end. It doesn't tell me what the actual MNP level used is, though, but it doesn't have to. The fixed serial line speed is all that I really need. -- Robert Claeson E-mail: rclaeson@erbe.se ERBE DATA AB