Date: Fri, 11 Apr 1997 13:20:26 -0400 From: Mike Tancsa <mike@sentex.net> To: neal@pernet.net, isp@FreeBSD.ORG Subject: Re: TS Holy War (was Re: Some advice needed.) Message-ID: <3.0.1.32.19970411132026.00add4f0@sentex.net> In-Reply-To: <Pine.BSF.3.95q.970411084231.9586A-100000@office.pernet.net > References: <3.0.1.32.19970411023357.00b84100@sentex.net>
next in thread | previous in thread | raw e-mail | index | archive | help
At 08:56 AM 4/11/97 +0000, Neal wrote: >On Fri, 11 Apr 1997, Mike Tancsa wrote: > >> At 11:17 PM 4/10/97 -0700, Vincent Poy wrote: >> >On Fri, 11 Apr 1997, Mike Tancsa wrote: >> > Hmmm, isn't there anyway to track down a external modem at all? I >> >mean if there was a problem, I should be able to turn the modems speaker >> >on and just listen to see if the modems are in fact connecting or not or I >> >can just try dialing in using a modem myself. >> >> Remember, people are dialing in 24hrs a day... Having people always >> monitoring the modems will cost you money...Connecting? At what speed >> though... Modems dont always fail 100%. They can start to become >> problematic and give lower connection speeds that the others. With >> external analog modems, you dont have any way of tracking this. Once you > >Err, last(1)? When we had FreeBSD TS's, we had no problem figuring out >what modems were being problematic. Last doesnt show you the connect speed.... Yeah, you can get averages and so on for average duration etc, but not the connect speed or amount of retrains etc... > >> have 50+ modems, snooping around them starts to become a real pain, and > >This I'll give you. That's why we moved to an ISDN box. > >[snip] >> stuff like this into your operating costs. Digital modems are far easier >> to manage, which translates to a lower operating cost... > >The only problem w/digital modems is that sometimes they don't work quite >right with other modems. This is true of any modem... We have analog PPIs, USRs and a Hayes Rackmount... each of them has problems with certain brands of modems :-( >> This is easy with a terminal server setup. Also, you want to be able to do >> PAP/CHAP so that your users dont have to use login scripts. > >Oddly enough, our BSD boxes did this also. The only thing missing was >Radius authentication. > >> >> > As for phone lines, what speed is a PRI exactly? >> >> A PRI is a type of ISDN service that offers 23 B channels at 64 kbs and one >> D channel at 64 kbs..You can sort of think of it as a bundle of 24 > >Er, 23 lines at 64K, 24 at 56K with inband signalling. Yes, correct... >> telephone lines basically... But they are digital so that they can carry >> both analog (regular modem connections) and digital (ISDN connections). > >Actually, they carry ONLY digital. An analog call comes in as a 64K >stream of PCM that the machine has to decode. Yeah, and this is what the 56K technologies depend on... There can be only one conversion from analog to digital on the virtual circut between the customer and the ISP...One of our local competitors was advertising that they were supporing X2 now... In fact, all they had were a bunch of Sporter X2 externals on the back of a terminal server! >> Modern terminal servers do all the necessary demuxing of the line so that >> you basically plug in one cable from the telco into the back of your your >> terminal server that contains all 24 of your 'telephone' lines. You dont >> have a bix block of 24 phone cords like you would going into 24 analog >> modems. Its just a T1 that your customers dial in on. The PRI has nothing > >This was exactly why we switched over. We DID find that around 80 lines >or so your cost/benefit of using BSD goes down enough to get an ISDN >product(and of course 56K is a good motivator). The only problem with PRI >is making sure your equipment and the phone company agree. That took two >weeks(plus 1 month installation from the CO). But since then we've had no >line related problems. Its not that bad now... In our area, the telco knows exactly what is needed to hook them up. When we say we want your "megalink service" they know exactly what we are talking about. Most of the TS vendors also have little FAQs on how to as for provisioning.... ---Mike ********************************************************************** Mike Tancsa (mike@sentex.net) * To do is to be -- Nietzsche Sentex Communications Corp, * To be is to do -- Sartre Cambridge, Ontario * Do be do be do -- Sinatra (http://www.sentex.net/~mdtancsa) *
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3.0.1.32.19970411132026.00add4f0>