bill@ssbn.WLK.COM (Bill Kennedy) (06/14/91)
This is kind of a follow up to my article asking about Trailblazer
registers but it's more of a report on the conclusion of the experiment.
First off another tip 'o the hat for Telebit tech support, they were
prompt, concerned, and knowledgeable. Moreover they were able to
overcome my ignorance and convince me that I was wasting my time while
never hinting that I was wasting theirs (which I was). Good folks and
the price is right!
The registers they had me fiddle with, S36 and S120 are not there for
every day use, they are there to try and salvage an otherwise unusable
connection. They diddle with what packets will and won't be used and
stuff like tone duration. They're kind of an intensive care unit built
in for when all of the wheels come all the way off. I tried every
non-lethal combination of both registers with varying results but no
success. The fourth call to Telebit produced the reason a cellular
connection is so difficult. Remember that the first three calls (all
returned promptly) were just trying to get me going and when all that
failed, we arrived at the reason my connection won't work (yours might).
Regardless of what voodoo had been applied to the way the two modems tried
to behave we could not overcome a fundamental difference in a cellular
connection, i.e. bandwidth and audio level. Telebit built the CellBlazer
to compensate for all of these differences, a TB+ can't cope with gross
excursions in bandwidth and audio levels. That made a lot of sense based
on my voice usage of the phone. The clarity is better and volume louder
than a similar conversation on a POTS connection. It makes a lot more sense
when you consider that most cellular connections are mobile and the emphasis
is on having you and the other party hear each other.
In summary, I'm giving up trying to get this to work here. To Telebit's
credit they weren't ready to give up, they had some more suggestions about
what I could try on each end to overcome the differences in dbm between
the POTS and cellular connection; I gave up before they did. They further
advised me that even if I had a CellBlazer on my (cellular) end, I might
not get good results without a companion CellBlazer on the other (POTS) end.
He wasn't trying to sell modems but was advising me on what it might take to
get the results I wanted. The good news is that if you defeat the cellular
smarts in a CellBlazer you have a plain old unexciting Trailblazer Plus.
When there's such black magic and witchcraft involved with this gear it's
refreshing to know that you _can_ put the genie back in the bottle and cork
him in :-)
Do you detect some "Rah Rah Telebit"? Yeah, you do. I didn't get what I
wanted but it certainly wasn't due to any lack of effort or cooperation on
their part. They did everything they could up to the point when it became
clear that I'm using the wrong modem. I couldn't ask for more than that...
I've heard of similar problems using cellular with USR and Intel modems but
neither of those manufacturers offers a model with the witchcraft in it :-)
--
Bill Kennedy internet bill@ssbn.WLK.COM or ssbn!bill@attmail.COM
uucp {att,cs.utexas.edu,pyramid!daver}!ssbn.wlk.com!bill