Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!bywater!arnor!ibm!rajkumr
From: rajkumr@arnor.UUCP (Ragunathan Rajkumar)
Newsgroups: comp.dcom.modems
Subject: T2500 CD problems for certain phone lines
Keywords: T2500, CD, Phone Lines
Message-ID: <1991Mar28.001515.102@arnor.uucp>
Date: 28 Mar 91 00:15:15 GMT
Sender: news@arnor.uucp (NNTP News Poster)
Reply-To: rajkumr@ibm.com
Organization: IBM Research
Lines: 26

We have a NetBlazer acting as a Slip/Telnet gateway using T2500 modems.
Currently, a maximum of 4 people call in.  In the lab, things work just fine.
Two callers have NO problems with SLIP or telnet.  Two others, including
me :-(,
have all kinds of problems: either CD never comes on, or if it does, junk
characters show up and the connection never materializes.  "Failed
synchronization" is the modem's diagnostic.  On rare occasions, things work as
they should but they are so rare, we have given up on these two phone lines.

I have tried all kinds of modem settings to get around this problem but the
situation is as non-deterministic as it can be: drives me crazy!  My suspicion
is that I am experiencing basic telephone line problems: most likely at the
local exchange or between the home and the exchange ("last mile"?).  The calls
are local (about 10-15 miles separate the caller and the callee modems) but are
in reasonably congested areas (I get the message "Your call did not go through!
Try your call again later" rather regularly).

Have others experienced this?  Is there a way to test/confirm my
suspicions?  Is
there a known solution?  Should I blame Telebit, the local exchange, or just my
stars?  ANY help would be MUCH appreciated.

---
Raj

Ragunathan (Raj) Rajkumar  rajkumr@watson.ibm.com  (914) 784-7931