Date: Fri, 23 Feb 1996 08:32:39 -0500 (EST) From: Robert Shady <rls@server.id.net> To: gjennejohn@frt.dec.com Cc: peter%thirdeye.com@inet-gw-1.pa.dec.com, freebsd-hardware%freebsd.org@inet-gw-1.pa.dec.com Subject: Re: ISDN Questions Message-ID: <199602231332.IAA06064@server.id.net> In-Reply-To: <9602231154.AA00568@cssmuc.frt.dec.com> from "garyj@frt.dec.com" at Feb 23, 96 12:54:45 pm
next in thread | previous in thread | raw e-mail | index | archive | help
> > A couple of questions about ISDN and FreeBsd.
> >
> > 2. Has anyone done anything that will work with the
> > Motorola BitSurfer Pro?
>
> not that I know of.
The BitSurfer PRO wouldn't need anything dependant on the kernel. Just drop
it in & treat it like a modem, run PPP to your provider & everything should
be fine.
> > 3. What are the advantages of a card over an external box?
> > Interrupt rate? Feature control?
>
> with a card you get the full B-channel speed (64 K/sec, 128 K/sec with
> channel bundling). Unless you have a really fast serial port (> 115.2)
> you can't get the full speed when you use channel bundling with an
> external device. Note that the II stuff doesn't currently support
> channel bundling, though, so this point is moot.
The other advantage of a card vs. an external device is that with an internal
card, you are talking to it in Syncronous mode, which simply means you send
a byte, it sends 8 bits. An external device talks in Asynchronous mode,
which simply means you send a byte, it sends 10-11 bits. Right off the bat,
this means you will get an approximate 20% loss of throughput with an
Asyncronous device Vs. a Synchronous device... Now, you through in the fact
that most external Asynchronous devices have to do the Asynch->Sync conversion
"on-the-fly", it's possible you may loose a little more than that.
-- Rob
===
_/_/_/_/_/ _/_/_/_/ _/_/ _/ _/_/_/_/_/ _/_/_/_/_/
_/ _/ _/ _/_/_/ _/ _/ _/ _/_/_/_/ _/
_/_/_/_/_/ _/_/_/_/ _/ _/ _/_/_/_/_/ _/
Innovative Data Services
Serving South-Eastern Michigan
Internet Service Provider / Hardware Sales / Consulting Services
Voice: (810)855-0404 / Fax: (810)855-3268 / Web: http://www.id.net
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199602231332.IAA06064>