Software modems

Forrest Dickinson fdickinson at morganhunter.com
Fri Aug 18 17:19:29 CDT 2000


I would have to agree about the benefits of an external modem especially if users dialin to the 
modem.  My experience with modems is that even if you have "top of the line modem" ,for example a 
USR V.Everything, the modem will still "hang" and power cycling the modem is the only solution.  
With an external modem you just power cycle the modem, with an internal modem you have to reboot 
your system.

Ben Webb wrote:

> I have to agree with Mike on this one, I will take the external modem every time.  Issues of 
bandwidth and latency aside, Those lights are a necessity.  There was a time, many years ago, when 
I was a sysop of a local BBS.  Any time I walked into my bedroom I could glance at my modems and 
know EXACTLY what was going on.  With a glance I could tell you if somone was reading mail, 
chatting, uploading or downloading.  On file transfers, I could even tell you the protocol.  I have 
seen the "modem lights" applications fail or mis-report information several times, plus they are 
always vulnerable to attack.  Let me give you an example.  User x has a windows machine set up, 
complete with winmodem.  User x is not particularly bright and so leaves a world writable share 
open on his hard drive.  Later on that day x dials into the internet.  After about 8 min. or so, 
script kiddy y's 31337 daemon scanner finds x's share, and dumps a custome version of BO, complete 
with an announce agen!
t.!
>   !
> As a result, x's machine sends a
> Another advantage is the ability to kill the modem without killing the machine.
>
> Ben
>
> ---------- Original Message ----------------------------------
> From: "Duston, Hal" <hdusto01 at sprintspectrum.com>
> Reply-To: kclug at kclug.org
> Date: Fri, 18 Aug 2000 10:30:39 -0500
>
> >Well, according to the article, the serial cable adds 26ms more
> latency like this.
>
> "26 ms (100 bytes down serial port to modem)
>  50 ms (modem's fixed waiting time)
>  28 ms (transmission time over telephone line at 28.8 Kbps)
>  26 ms (100 bytes up serial port at receiving end)
>
> Thus, the total time is 130 ms each way, or 260 ms for the round-
> trip."
>
> I will grant that as broadband becomes more and more prevalent,
> that this will become less of an issue, but I do believe that
> latency is just as important as bandwidth.  Bandwidth is roughly
> equivalent to how much data can be put in the pipe at once, but
> latency is equivalent to how long the data takes to get to the
> other end.  ISDN and modems have roughly similiar bandwidth, but
> ISDN has MUCH better latency, and that is why it is so much
> faster.  A station wagon full of CD-ROMS going down the interstate
> has incredibly huge bandwidth, but the latency is REALLY bad.
>
> Hal Duston
> hald at sound.net
> If Al Gore invented the internet, why is it named after George W. Bush
>




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