Xref: utzoo comp.dcom.modems:3582 comp.protocols.appletalk:1667 comp.sys.mac:28460
Path: utzoo!attcan!uunet!tank!eecae!mailrus!nrl-cmf!ames!coherent!dplatt
From: dplatt@coherent.com (Dave Platt)
Newsgroups: comp.dcom.modems,comp.protocols.appletalk,comp.sys.mac
Subject: Liason network bridges vs. Telebit TrailBlazer Plus modems
Message-ID: <22320@coherent.com>
Date: 15 Mar 89 21:48:38 GMT
Followup-To: comp.dcom.modems
Distribution: comp
Organization: Coherent Thought Inc., Palo Alto CA
Lines: 36

[Please pardon the cross-posting, and note the Followup-to header.]

According to the "Mac the Knife" column in the 3/14 issue of MacWeek,
there's a design peculiarity in the Liason network bridge software that
can have severe repercussions if you use this software with a Telebit
TrailBlazer Plus.

It seems that the software periodically sends a modem-configuration
command string to the modem.  According to the article, this occurs once
per minute [I assume that it occurs only when the modem is not "talking
to" another modem... i.e., the bridge is not "alive"].  This
configuration command includes an "&W" sequence, which instructs the
modem to write the configuration information into its nonvolatile
memory.

The TrailBlazer Plus's nonvolatile memory is (according to the article)
implemented in EEPROM, which has a life expectancy of 10,000 write
cycles.  At 1 write per minute, Liason could run through this lifecycle
in less than a week!  The results would be bad... you might find
yourself unable to change the configuration of your TrailBlazer, or find
that the modem had gone entirely belly-up due to inconsistent EEPROM
settings.

So... if you have Liason and a TrailBlazer Plus, be careful!!  You might
want to call InfoSphere and ask for further information and/or a fixed
version of Liason.

Disclaimer:  I'm just passing on what I read;  I can't attest to the
truth of this report.


-- 
Dave Platt    FIDONET:  Dave Platt on 1:204/444        VOICE: (415) 493-8805
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