[TriLUG] Help - 3COM US Robotics ISDN TA (USB) Inconsistency in connecting.

[William W. Ward]

Bye bye Microsoft Windows 2000.  After an exceedingly annoying evening,
Linux is no longer the secondary partition on my machine.  There can be only
*one*.

A little bit of advice if you please, regarding a curious behavior of my
ISP's dial-up pool and my ISDN TA:

I own a 3COM USR ISDN TA - this is the successor to the 3COM Impact IQ,
adding USB connectivity.  This particular modem is compatible (and
explicitly mentioned) with the Linux USB implementation bundled with RedHat
7.2 (as it comes off the distribution CDs.)

Getting to the modem isn't the hard part.  I can connect to Intrex with it
fine, once in every 4 or 5 tries.

I'm using the WVDIAL utility to accomplish my dialing and authentication.
This may be my first problem.  Checking the messages log, I notice that
there is a difference between the sequence of events after the connect light
on the TA illuminates.  The "CARRIER 128000" result message does not always
display, although a connection IS established.  WVDIAL is waiting for this
result before proceeding with authentication or handing off to PPPD.

On a successful connection, the first channel (I am using MultiLinkPPP)
comes up, "CONNECT 128000" is displayed, and WVDIAL continues on to a
successful link.

On an unsuccessful connection, the first channel comes up, NO connect
message is displayed, and about 10 seconds later, the LCP or whatever
preamble is received (you know, the part with all the }}}'s) but the dialer
does not continue, and eventually the link times out.

One can assume that some minor difference in the unit on the other end is
causing a reaction.  It is also safe to note that if I do NOT use MPPP, but
stick with a single channel, that it connects on all attempts.

I *believe* that the most practical solution is to switch to using the CHAT
dialer and set up a script that simply ignores the result code and waits for
the preamble, but I'd like to hear more seasoned users comment on it.

Additional notes:
I cannot get cable data service, nor a digital subscriber loop, and the
latency of two-way satellite is unpalatable.  I depend on the POTS ports on
the TA to run my home voice lines, although I have an Ascend Pipeline 100 I
could theoretically use.  I'd still have to employ a Linux-based NAT
solution since I require VPN passthrough for my work laptop.
I haven't sacrificed my token virgin to the computer ghods yet, but I think
that might be on the horizon if I can't get a consistent connection out of
this bastard.

Your time and attention are appreciated,
-b-