Date: Fri, 11 Apr 1997 08:56:43 +0000 (GMT) From: Neal <neal@pernet.net> To: isp@freebsd.org Subject: TS Holy War (was Re: Some advice needed.) Message-ID: <Pine.BSF.3.95q.970411084231.9586A-100000@office.pernet.net> In-Reply-To: <3.0.1.32.19970411023357.00b84100@sentex.net>
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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. > 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. I know there is dicussion about PM3's and Zooms. We had some issues with our ascends also. My understanding is that both vendors have cleared up the problems to some degree, and we haven't had any problems for some time(just so I don't sound whiny). > 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. > 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. > 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. > >Since the > >machine will most likely have a T1 or 56k line going there since there are > >customers who need dedicated services so probably a T1. For the terminal > >servers, isn't Annex 3 any good anymore or do they cost a lot more than > >the Livingston's and the others you have mentioned? My general impression of Annex has been a screamed NO. But bear in mind that's just an impression. Now, a couple little thoughts just from me: 1:If you're strapped for cash, don't even try to start. You need to be able to count on anywhere from $100,000-300,000 to run. 2:As odd as this sound, make friends with the phone company. We get ISDN B channels for $13/month. Do you think they would have "found" this tariff if I was pissed at them? 3:Decide what you want to do beforehand. If you WANT to be a big-1000 line ISP, go ahead and start with a PM3 or MAX or whatever you decide on. But if you are going to stay small and don't think you can afford $14000 for 48 analog lines, look into a BSD box or something equivilant. 4:Avoid telebit like the plague. If you talk to uunet, they'll try and sell you one. Don't buy. I speak from experience. -- Neal Rigney, PERnet Communications, (409)729-4638 neal@mail.pernet.net
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