[comp.dcom.modems] Trailblazer Plus BA5.00 versus T2500 V.32 tones

andrew@ramona.Cary.NC.US (Andrew Ernest) (07/01/90)

I have a 2-year-old Trailblazer Plus that I upgraded to BA5.00
firmware about a year ago.  Things have been smooth sailing until I
recently tried to call a T2500 which issues its tones in the following
order:  V.32, slow, PEP.  I have S7=60 and S50=255.  My modem waits
through the V.32 and slow tones fine.  The problem is it continues to
wait right through the PEP tones too!  Has anyone else had this
problem?  It would be helpful to get mail from people who've either
failed or succeeded at calling a T2500 which issues V.32 tones before
PEP tones.  Please include the firmware level in your mail.

Thanks a lot.
-- 
Andrew Ernest <andrew@ramona.Cary.NC.US>

ralphs@halcyon.wa.com (Ralph Sims) (07/01/90)

andrew@ramona.Cary.NC.US (Andrew Ernest) writes:

> order:  V.32, slow, PEP.  I have S7=60 and S50=255.  My modem waits
> through the V.32 and slow tones fine.  The problem is it continues to
> wait right through the PEP tones too!  Has anyone else had this

Would this happen if you set your S50 register to 255, forcing yours
to synch with PEP _only_?  If you _know_ that you are dialing a
Telebit modem, you can dial out with this setting without fear of
a deadly embrace (well, mileage _may_ vary, but not often...).  I
think that if you set your end to hang in there until the other side
gets its PEP flowing, you'll be fine.

Please let us know what you find out...


--
 "These are the days of lasers in the jungle..."
  Paul Simon, "The Boy In The Bubble" on the _Graceland_ album

andrew@ramona.Cary.NC.US (Andrew Ernest) (07/02/90)

I've already received enough responses to formulate the following
summary:

+ The problem appears to have been introduced in the TB+ 5.00 firmware
  and apparently still exists in 5.01.  TB+ modems still using 4.0
  firmware work fine.

+ The "fix" is to set S99=1 in the answering T2500.  This is an
  undocumented register which Telebit tech support is telling people
  about with respect to this problem.

This fix is rather awkward since I'm not in control of all the T2500s I
call.  So I would like to make the following plea on behalf of all TB+
owners with 5.0 firmware:

	If you, the reader, operate publically accessible T2500s which
	issue V.32 tones before PEP tones, please set S99=1 in your
	default NVRAM configuration.  For example:

		at &e0 s99=1 &w0
-- 
Andrew Ernest <andrew@ramona.Cary.NC.US>