VOIP

[splicer480]

Does anyone have any experience with setting up a VOIP phone system? We have a very old phone system in our plant and instead of wiring the WHOLE plant for a new phone system I thought we could use our newer (5 year old) ethernet network and these http://www.3com.com/products/en_US/detail....mp;sku=3C10402B Any info is appreciated

[Nathan]

I have some VoIP experience on a personal, small, and medium scale. I'd hardly consider myself a VoIP Engineer, but have some insight for you based on my experience on various scales: Personal - I use Vonage on a daily basis with a 'regular' phone plugged into a gateway. I dragged my setup around several countries on different continents. It worked great, including receiving calls. The pricing is amazing compared to phone companies, who think we still live in the 1960s. Skype is equally cool. These services are cheap, work well, and trivially simple to use. Small business - One clever but very inexperienced employee replaced about 10 phones with VoIP setup. He used a PC with some kind of cheap but very cool software as the gateway and managed to pull in POTS lines with a reasonable long distance service. Users were annoyed by quirks in the system that you wouldn't have thought of - call transfers, voicemail, which lines ring, caller id, out of office settings, etc. People just want a phone to "work". I don't remember any network problems, but all cabling went to one, maybe two interconnected switches. Small/Medium size (with a big budget) - Cisco VoIP solution. When the phones are set up properly they work great - usable (not configurable) with little training and feature rich! I was shocked and felt ripped off by the infrastructure commitment. You hear/assume "it works over IP - just plug it in your existing network". Not so! It works much better with newer VoIP capable switches. Beyond PoE, VLANs really need to be configured properly and QoS is a must, which aren't trivial. It took a few days of troubleshooting of our very talented Network Engineer to figure out what was making the phones all reboot periodically. Gatekeepers and Call Managers are not too difficult to figure out, but expensive. You can set up your own phone "number" system that's off the phone network, create conference call groups, elaborate call answer rollover schemes, easily transfer phone numbers for roving users, have some numbers ring on many phones, seamlessly forward numbers externally (to a cell phone) after a few rings, etc. The pricing of this type of setup can get staggering. Bottom line - VoIP provides a huge set of cool features at a great price (once in place). I highly recommend that anyone use a managed setup beside their normal phone. It can get pretty technical to set up/configure/manage your own rig, particularly if you have users expecting to conduct business with it. VoIP is better treated as "service based", like infrastructure where users better concern themselves with results over the details. Definitely TIAS before ripping out your existing phones! Edited April 29, 2008 by Nathan

[splicer480]

First, thanks for the very detailed post Nathan. I checked a couple web sites like 3Com, Avaya, and Cisco. They all seem to have their own IP phones and equipment that are pretty similar to each other. My Hubs/Switches are 3Com 24 and 12 port, 10/100 speed hubs. They are not POE (power over ethernet) but I have receptacles near just about every phone that would need hooked up. I don't know if you or anyone else could answer just a few more questions I have? How would the existing phone connection (ie: AT&T) tie into my network? Basically the phone service at the outside box coming into the building with all the lines, extensions, long distance, etc.. Would it come in like a cat 6 twisted pair into a VOIP Gateway Server and out of that Gateway Server with cat 6 to my Hub or some kind of a phone Computer/Server then to my hub? 2. I have a few 10 or so regular analog phones in the plant that would need to remain. Is there a box that would let me tie in those few phones thru the VOIP network? Again thanks for any help.

[Nathan]

PoE is about the least important detail of what I mentioned - it's mearly a convenience. The real detail to evaluate relates to the latency of your Internet connection. VoIP doesn't take a lot of bandwith, but voice quality noticably degrades with latency. Implementing a QoS setup can work wonders. For me at home this was purchasing a D-Link "gaming" router and elevating the priority of my VoIP phone. The result, massive downloads/uploads and VPN connections no longer interrupt my phone calls. The clarity is perfect, even from halfway across the world. The other intelligent thing to do would be set up a separate VLAN for the VoIP phones, which helps segment broadcast/multicast traffic. The "small" setup used a PC as a "gateway" that could pull in both long distance and POTS lines. I'm not sure what kind of equipment it used (modem, card, etc), but know that it's possible. This works a bit differently if you have T1 voice lines, but is also possible. I would guess that there's equipment that provides female RJ11 and RJ45 jacks to do what you describe - that's actually what my Vonage Gateway resembles, except that it uses the "Vonage Cloud", not a local VoIP setup. I'd recommend contacting your local phone company for a quote. You provide them your requirements and they'll come out and give you a technically detailed idea of how to continue. It may not be a bad idea to let them set it up - the decision is yours. I strongly recommend evaluating the system beside your current one before committing unless you have a professional contracted to provide some specific level of service.

[splicer480]

Thanks for your help Nathan.

[Nathan]

No problem - let us know how it goes!

[paulengr]

Yes, however, this may not be the best choice. I highly recommend that you keep at least a couple phone lines off the VoIP network unless you want to rely on cell phones for troubleshooting/emergencies. Second, you've got to consider fax machines. They do NOT like to be on VoIP. So there are two choices if you don't want to keep those lines. Either buy a fax gateway machine (Cisco sells a nice one) and set it up with some network scanners in the appropriate places (fax delivery=E-mail, outgoing fax via scanner/email), or else contract it out to one of the internet fax services. Overall this is one area where it doesn't hurt if you talk to 3-4 local business telephone services and describe what you want and let them explain how to do it and offer services to set it up. If you screw this up, it's even worse than the usual IT "oops" moves that tick people off. The trouble with phone companies in general is that they have just worked for years without any problems. So people take it for granted that when you pick up a phone, it should just work. There is by the way a very good telephone tester that looks for more than continuity that you should invest in if you are maintaining phone lines. It tone tests to look for more than just continuity and can reliably tell the difference between a bad (noisy) and good line. Any telco technician can tell you the name. But of course I can't recall the name right now (since I'm not a telco technician).

[Nathan]

Thanks for the clarification and expansion of my points, Paul. I especially agree with contacting your ISP versus (or in addition to) telcos. I too would favor Cisco provided that you have good technical help - it can get really complicated. It really isn't one of those things that you can "just figure out" without cracking some serious manuals or training - a serious time commitment either way. Once again I emphasize that a full VoIP solution may not be right for your setup. Carefully consider your goals and plus/minuses. Edited May 4, 2008 by Nathan