bill@twwells.uucp (T. William Wells) (02/02/89)
I have a Telebit Trailblazer+ and am running Microport V/386 3.0e. I
had a request from a friend who uses my system for MNP. Well, I tried
setting MNP (S95=2) but found that my modem no longer works after
that, at least when talking to a non-MNP modem. When I cu over to
another system, the modem appears to pay no attention to text sent to
it. Since I know nothing about MNP, I am at a loss.
Any suggestions on what to do next?
---
Bill
{ uunet!proxftl | novavax } !twwells!billgk@kksys.mn.org (Greg Kemnitz) (02/03/89)
In article <367@twwells.uucp> bill@twwells.UUCP (T. William Wells) writes: >I have a Telebit Trailblazer+ and am running Microport V/386 3.0e. I >had a request from a friend who uses my system for MNP. Well, I tried >setting MNP (S95=2) but found that my modem no longer works after that, >Bill { uunet!proxftl | novavax } !twwells!bill We experienced a similar problem recently. The folks at Telebit gave us a "fix" -- feed the command ATJ6S39=3 to your 'blazer... it seems to make a world of difference. As Telebit tech support explained, with the 4.0 firmware they implemented MNP 3 "plus a bit...". It appears that the "plus a bit..." is what causes the problems. The above-referenced commands cause the blazer to be in true MNP3, rather than the enhanced mode. As a side note, it has been my experience that the folks at Telebit are usually able to give a good pointer towards a solution for most problems we encounter. It is nice to deal with a company that really supports what they sell. -- Greg Kemnitz / K and K Systems / PO Box 41804 / Plymouth, MN 55441-0804 Domain: gk@kksys.mn.org / UUCP: ...!rutgers!bungia!kksys!gk Voice: (612)475-1527 / Fax: (612)475-1979
wtm@neoucom.UUCP (Bill Mayhew) (02/04/89)
One must disable MNP protocol before dialing into a site that echoes characters and also not equipped with an MNP modem. The reason is that the string of entrainment characters sent from both the originate and receive ends are the same in the MNP protocol. Thus if the other end is unix and puts up a login: prompt with echoing enabled, login will echo back the entrainment sequence to your modem, as login thinks that you are entering your userid. The result is that your modem thinks the other end has MNP when in fact it does not. If you are using a modem that has level 3 or higher MNP, you'll be locked out for the remainder of the call, as the modem will try to switch over to synchronous operation. So much for stupid design features! The way around the bug is to set S92 appropriately for whatever site you are dialing out to in your chat script. You can probably safely leave MNP enabled for dial-ins without incident. It is only a bug while dialing out to a non-MNP site. On a modem that doesn't have defeatable MNP (does such a thing exist?), a way to get around the MNP bug would be to prevent the other host from echoing anything for seven seconds after its modem goes off hook. If your own modem doesn't receive an entrainment sequence within seven seconds of trying its own sequence, it is supposed to assume the other end is a garden variety modem. --Bill wtm@impulse.UUCP ...!lll-winken!scooter!neoucom!impulse!wtm