On Mon, Apr 7, 2008 at 2:46 AM, Alex Balashov <[EMAIL PROTECTED]> wrote: > Steve Totaro wrote: > > > A T3 MUXed into 28 T1 PRIs in one, or a few trunk groups inherently > > has redundancy. If a box dies, the calls are dropped (unless you are > > doing reinvite) and any call backs go right to the > > Ts that are not in alarm. > > True - and if you're simply using CT3 as an economical method of getting > say, a dozen T1s into a gateway, that is probably an advantage. But if > that's the case, it would not be cost-effective to shell out extra money > for additional PCs with quad T1 cards just to provide failover in the > event that the primaries fail. 80/20 rule and all that.
7 HP DL320s, RAID 1 with Quad Sangoma. Not a dozen but more than twice that, 28 T1s. What is your cheaper solution? Also, have two cold spares in the rack. DL 320s are cheap and "rarely fail" using 1.2.X. I actually cannot remember a single failure over years of operation. I have no idea what you mean "if the primary fails". Are we using Windows NT, does the secondary domain controller take over? > > The point is that most people that want a DS3 interface really do want > to pump in a DS3's worth of calls, more or less, in which case they > really can't afford to have those DS1s going spare just for redundancy's > sake. And if you are doing substantially less than a DS3's worth of > calls, you probably shouldn't be looking at a DS3 interface to begin > with unless that's just an incredibly lucrative way to get channelised > PRIs in from a vendor - and with typical the cost of UNE DS3 loops vs > T1s, that's not necessarily so. I don't think you have much experience with DS3s, correct me if I am wrong. While pricing many solutions, it is either 14 or 16 T1s where a DS3 becomes about the same cost for the loop, that is a lot of wiggle room. Would you pay for 16 of something you need or take 28 of something you surely will need down the road. > > Secondly, an industrial-grade ISDN media gateway designed for telco > environments (like a Cisco AS, say) isn't going to go down frequently > enough to merit this kind of concern. Don't get me wrong, I am the last > to go on record saying that Cisco voice equipment (or any other) doesn't > fail from time to time -- ha. But, again, 80/20 rule. A PC is much > more likely to fail within the same MTBF. > > So yes, a single gateway handling a DS3 can go down. But so can an M13 > mux. You've got single points of failure either way. Read the specs on the Adtran 2800 MX13. I don't think it is going to fail unless you smash it or pour coffee on it. Google it and RTFM before you spout off about a product you obviously have no knowledge of. > > If one is in the sort of environment where such high availability really > is a concern (typically a telco setting), one probably needs to invest > in a big DACS and redundant, protection-switched DS3 paths (and > protection line cards for them on the DACS side) as well as redundant > gateways, or at least redundant DS3 line cards in the chassis. At that > point of stringent availability, this discussion becomes a wee bit moot > because most likely you would not be using Asterisk and PCs in such a > setting anyway. We are talking DS3 here, not OC12. Talk about overkill. > > > > Running stripped down Linux OS boxen with quad port T1 cards and four > > or five lines in extensions.conf, no unneeded modules or software > > loaded, asterisk 1.2, entries for zaptel and zapata, and a couple > > entries in sip.conf builds a worry free solution. Asterisk uptime 2 > > years, system uptime two years and twenty minutes. > > Yes, but total cost of ownership goes up because you need someone to do > all that, and even so, despite the impressive uptime you mention, PCs do > need a lot more maintenance, upkeep and worry. Original setup takes a little time, reviewing the logs a couple of times a weeks takes a minimal amount of time. Rotating logs should be automatic, what else is there? > > With dedicated media gateways, you just plug in, set up and it works. > They are essentially small servers, some with solid state and flash, others with real hard drives. Ever open one up? I would prefer to pop a case and replace a T Card, memory, hardrive, powersupply, fan, then waiting on an RMA. Especially when your call center is losing $26k an hour. Thanks, Steve PS, all I know is what works well for a 15k-20k calls a day center with the average call lasting fifteen minutes and EVERY second of every call being recorded. Maybe I am a newb. _______________________________________________ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users