On Thu, Sep 28, 2006 at 08:44:55AM -0600, Colin Anderson wrote: > >I concur with your approach, but "Tier 1" means as little here as it > >does when evaluating Internet backbone carriers. could you expand on > >what evaluation criteria you use? I'm going to be pre-speccing some > >stuff myself this month... > > Sorry I should have been more clear. A good Asterisk install needs a > holistic approach to use a hippy dippy phrase.
Yeah; I'm a Carlin fan, too. > A Tier 1 server, which is a > midrange to high end name brand server from the Big 3 (Dell, HP/Compaq, IBM, > am I missing someone?) is usually highly optimized for bus bandwidth > although that design was intended for a different use - usually massive disk > I/O. As well, a Tier 1 server will have two seperate, independent PCI buses > and this to me is a critical feature - it allows you to completely separate > your TDM traffic from network, disk I/O etc. On my big production Netfinity, > I took great care to ensure the Digium cards were all on their lonesome on a > single bus, and everything else on the other bus. This is how I can run two > TE110's in a single box with no problems. zttest does not give me 100% all > the time, but on the other hand it *never* drops below 99.9987%, even under > load. Can I suggest that if the metric on zttest is 100=acceptable, 99.9987= borderline, then someone needs to rewrite zttest? :-) > I selected this Netfinity because of the obvious care put into it's > design, but the specs are unimpressive: quad Xeon 700's. CPU is over rated > for Asterisk, IMO unless you are doing tons of transcoding and if you are > doing that, then your design is flawed. Well, I think so. But I'm planning to have most of my audio on GigE between media gateways, anyway. > Anyway, the holistic approach (to go on a small rant for the newbie lurkers) > be summed up as follows: > > 1. Good box, see above To be a bit contrarian: big-name boxen aren't *always* the best choice on engineering grounds, *because you can't always find out what they're built with*... and sometimes it matters. > 2. Good LAN - this is so critical and so often overlooked in the day and age > of guys crimping their own cables and running $150 switches. You can't do > that, and if you do, you do so at your own peril. Managed swiches, > professional cable installation. This is not a problem for me since I *am* a > professional cable installer but I have actually witnessed people making > patch cables with a flat blade screwdriver and a hammer! Hee. > 3. Tuning of the LAN - VLAN's are good. QoS packets are good. Switches that > honor the QoS packets are good. Switches aren't *that* expensive; you would really VLAN the media with the ops? > 4. Handset selection - this is another biggie. I've selected Snom 360's, and > yes they have warts, but they are feature rich for the price and Snom is > really good about revising firmware. When you select handsets, GET YOUR Oh, yeah. Though, 2500's are hard to get wrong. ;-) > USERS INVOLVED. > 5. Tuning of Asterisk box itself - this cannot be under emphasized. This is > a very important step and tuning methodologies vary according to distro, > skill of the admin, and particular circumstances. I've learned *way* more > than I ever wanted to about processor affinity sinc I started using > Asterisk. Write a book. :-) > 6. Termination of PSTN. Basically I would never do an Asterisk install where > I was forced to do something stupid like aggregate a dozen Centrex lines or > some mickey mouse deal with FXO ATA's or whatever except for a hobby or > prototype install. PRI, BRI, IAX or SIP, don't mess around with anything > else. Yep. > 7. Relationship with provider. What is their SLA? Is it the incumbent or the > clec? An incumbent will be more expensive and more difficult to deal with > but they will tend to be more reliable. A clec will be cheaper and they will > be way more accomodating but you will most likely not get five 9's from > them. A VoIP provider should never be trusted, period. You will not get five > nines from them, ever. Plan failover situations accordingly. "SLA? What's a 'SLA'?" :-) Amusingly, a client's * box went down this morning. I didn't get the washout, but the mitigation wasn't well planned either -- everyone with an Asterisk box should know what they're going to do if it falls over, in detail. In a notebook. Just like when the nuclear missles start going. > 8. Plan plan plan plan. A good install of ANYTHING is 80% planning 20% doing > it. What is your plan when your primary PSTN provider fails? What is your > plan if your Asterisk box goes pear shaped? My dialplan can survive either > PSTN, WAN or LAN failure (albeit with reduced functionality). I also keep a > cold spare, an identically configured box that I can literally throw into > the rack, turn it on, plug in the PRI's and no problem. TXT! TXT!! > 9. Internet bandwidth and latency. I am fortunate enough to have a great IP > provider. Ask for demos - most guys will install a 90 day trial or something > like that. Do not believe the brochure, get the product installed and put it > under load. Yep. > 10. Traffic prioritization at the IP demarc - total no brainer. Never hurts. > 11. Constant, constant user feedback and remediation. If you are not talking > to your users, your install will ultimately fail even if you have the best > of everything. Underpromise and overdeliver. Never loose sight of the basics > - they have to pick up the phone, and it has to work. Always. I was musing on giving station users a list of pseudo-CLASS dialcodes they could punch to mark that there was a problem with a previous call, so it would go into the logs and could be checked latter. Cheers, -- jra -- Jay R. Ashworth [EMAIL PROTECTED] Designer Baylink RFC 2100 Ashworth & Associates The Things I Think '87 e24 St Petersburg FL USA http://baylink.pitas.com +1 727 647 1274 "That's women for you; you divorce them, and 10 years later, they stop having sex with you." -- Jennifer Crusie; _Fast_Women_ _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
