Date: Sat, 17 Apr 1999 23:08:20 -0400 (EDT) From: Chuck Robey <chuckr@picnic.mat.net> To: "John T. Farmer" <jfarmer@goldsword.com> Cc: bill@bilver.magicnet.net, freebsd-isp@FreeBSD.ORG Subject: Re: cheapo 56k hardware Message-ID: <Pine.BSF.4.10.9904172300490.15061-100000@picnic.mat.net> In-Reply-To: <199904180252.WAA17151@rapier.goldsword.com>
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On Sat, 17 Apr 1999, John T. Farmer wrote: > > On Sat, 17 Apr 1999 17:11:21 Chuck Robey said: > > On Sat, 17 Apr 1999, Bill Vermillion wrote: > > > The problem you have is that any digital modem at 56K as the ISP is > > > going to require a PRI (most probably) and a device that > > > interfaces. > > > > > > 56K modems can't be used at the ISP because 56K to 56K is limited > > > to 33.3K > > > > > > > If this is a multithousand buck answer, it's not gooing to be > > > > really practical, so please don't make gold plated suggestions > > > > without awfully good reasons behind it (better than just enhanced > > > > reliability). > > > > > > 56K requires a digital link from the ISP through telco, to > > > destination so there is no D/A conversion. The home to ISP > > > is analog and therefore requires a D/A at the home and an A/D at > > > the ISP. Doing two AtoD and DtoA conversions limits you to 33.3. > > > > > > It's not going to be cheapo. You can find all sorts of devices on > > > the used marked below 56K - but the last time I looked the 56K > > > devices were still pretty expensive in comparison. > > > > Ahh. The ISP in question has a 128K frame relay line, but that would be > > a drop in the bucket. So he has to go buy the service from the telco? > > Or he has to have a T1 from the telco, those are the alternatives? > > > > Yecch! > > No the line that they have in for their _backbone_ Internet has _nothing_ > to do with what's required to offer 56k service. I don't quite understand what made you think I was confusing them, I understood the difference. I didn't like the idea of purchasing another T1 (the 128K frame comes in via a T1.) > > I'm assuming that they currently have POTS lines either into rack modems > or individual modems (here after referred to as POTS modems). The POTS > modems are served by the existing terminal server. No, they're served by serial ports from PC's. Like to have a terminal server, but this is a *small* isp. Effect is the same, except it doesn't hit the ethernet. > Two approaches are possible. The USR/3com way or the Ascend way. (I've > tried both...) Each approach is also available for either BRI (2B+D) > ISDN circuits or PRI (23B+D) circuits. The key is that the dialup POTS > lines _have_ to be replaced by digital circuits of some sort. > > The USR method (using BRI circuits) involves: > > 1. Find an MP/8I or 16I modem bank (new, they're $2800 to $3900. > Used you might be able to grab one $2k. They go fast on > the used market.) > > 2. Order 4 or 8 BRI ISDN circuits from the telco in a hunt group. > > 3. Replace the POTS modems with the MP/8(16)-I box, configure the > ports for 115k (or 230k if possible), set all the SPIDs, etc. > and turn the customers loose. > > The MP/8-I bank handles 8 incoming analog calls, x2 or v.90. The > MP/16-I handles 16. Either will serve 64k ISDN dial-in. They don't > really handle 128k ISDN very well. You can use the Courier I-modems in > place of the MP boxes at the cost of 1/2 the available channels. > > If you want or have to go with a PRI solution, then the cheapest 3com > approach is to find a used Total Control chassis with 1 or 2 > PRI interfaces and 24/48 v.90 modems (the newer DSP ones preferred). > This replaces both the terminal server and the POTS modems. Used, > this box is in the $6k to $7k range. (We won't get into the Netserver > vs. HyperArc fiasco... or the cost of software updates...) > > The Ascend approach for either BRI or PRI lines also replaces the existing > terminal server & POTS modems with a new box. For BRIs, the Max1800 with > 1 or 2 Series56 digital modem cards is the call. Used it runs $2k for the > base unit & $1k to $2k for the digital card(s). Handles upto 8 BRIs, > serves up 64k or 128k ISDN cleanly, serves up 56k (k56 or v.90) upto the > number of modem ports (8, 12, or 16). For PRI service, the boxes to look > at are the MAX2012, MAX2024, MAX40xx, or MAX60xx. They use the same modem > cards as the 1800. > > The MAX 20xx boxes are the same basic unit as the MAX1800 with the BRI > interfaces replaced with 1 PRI port. The MAX40xx boxes have 2 or 4 PRI > interfaces (older boxes have 4 interfaces but not enough cpu housepower > to handle a full load of modems). The MAX4 series have been "end of > lifed" by Ascend & soon won't run the newest versions of TOS. The > MAX60xx will handle a full load of 96 modems (4 PRIs) and is still in > full production. > > The MAX20xx boxes can be found used with 12 or 24 modems for $3k to $4k. > The 40xx boxes can be found used with 24 or 48 modems for $6k to $7.5k. > The MAX60xx starts at $10k and can cost upto $30k. > > The approach that I would choose would depend on what they're comfortable > with (brands, etc.), the availablity of lines, their total budget, and > the number of clients they're attempting to serve. For example, in > Bell$outh land, BRIs are ~$100/mo. and no distance-based line charge. > PRIs are ~$1200/mo. and are delivered via a T-1 span that you can > figure on paying ~$500/mo for. If you're lucky enough to be served > by a decent ISP-centric CLEC, then you could get PRIs in the range of > $300 to $500/mo. and rack space for ~$300 to ~$500/mo. YMMV. I'm served by Bell Atlantic, which is still trying to get a million bucks for every bit they sell. I hear of those deals elsewhere, and I get *very* envious. Thanks for the helpful summary. It's not great news, he wants to add maybe 2 56K customers, and that makes buying another T1 hard to justify. Maybe I gotta see about ISDN. This is changing now, I think maybe Bell Atlantic is either going to wake up soon, or is waking up now. Their deals are about the worst in the country. I'm glad I don't have to worry the bucks on this. ----------------------------+----------------------------------------------- Chuck Robey | Interests include any kind of voice or data chuckr@picnic.mat.net | communications topic, C programming, and Unix. 213 Lakeside Drive Apt T-1 | Greenbelt, MD 20770 | I run picnic (FreeBSD-current) (301) 220-2114 | and jaunt (Solaris7). ----------------------------+----------------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message
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