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Using VoIP to Connect Phones Between Offices?
virtualPhoneWire asks: "My office is expanding to include a new facility which is just a few hundred feet just across the parking lot. The building is just far enough away to make running cable a pain in the neck, so to get data over there, we're setting up an 802.11b link, and a couple of simple Linux routers to handle the traffic, no problem. Now, the people in this new building are going to need access to our phone system, a simple Avaya Partner II key system. I would like to think that there is a way that I can patch them into our switch using some kind of
VoIP technology. The ideal being that we can issue a couple of IP phones that plug into the Ethernet back-bone, take their queue from my DHCP server, and linkup with a device on the other end that ties them into switch thus giving them access like any other phone. As an after thought, being able to give other people on our network, both inside the building and via our VPN, access to this gateway to
make calls would be a real bonus. We're considering an upgrade to a real PBX, but we would like to do this without blowing the pension plan. We would like to having something scaleable, and open source, if possible. Any thoughts?"
Call your system vendor. They will most likely tell you there is nothing that can be done :).
I looked at some voip quotes recently, one of the systems required lisences to be bought to use the phones over IP. Something like Four thousand for 10 phones. I think avaya has a module you can put in to your rack, and plug into your switch (its designed to also do power-over-ethernet injection. Be aware, the phones are going to cost you an arm and a leg.
On a second thought, buy two channel banks from adtran, they will take the voice channels to IP, then you can kick it over a wireless link.
this will cost like 1000 usd.
normally, a channel bank will go for 400-600.
I used to work for a company that did solutions like that. What we normally did was use ISA Micom cards (FXS). Micom are now owned by Nortel, and last I checked there were thousands of these cards still available through distributers. If you want to roll your own solution, get a rackmount case witha failover power supply, and a small processor ~ 266. Load the _DOS_ software and assign IP's,etc. Tie it into your existing PBX as trunks, and you are set.
If you are not inclined to roll your own, I do recommend Nortel's solutions, quite possibly because they tended to be the most relaible to use.
Check www.digium.com.
They are the makers of Asterisk PBX and they'll probably have a solution for you. Going the IP phone route is probably more expensive, unless you have a small office and are _NOT_ planning to grow.
Two asterisk boxes and a channel bank would be much more scaleable and cheaper. RJS
http://www.linuxtelephony.com/
I work for a small private college and we have been looking at VoIP solutions. We are currently on a Centrex (sp.) setup which is basically a situation where we rent our lines from the phone company for a per month charge. No PBX or any similiar equipment. The solution is extremely expensive for 1200 phone lines (800 are inactive 4 months out of the year and are turned off to save $$ - dorms). We have looked at both VoIP and PBXs. VoIP provides consolidation of your voice and data networks which can be quite convenient. I have read of security issues with VoIP, but I cannot really say much about them without further study. The payback on VoIP vs. PBX is pretty substantial. VoIP payback 3 years, PBX 5 years. VoIP is easy to scale and grows with you pretty easily. PBXs require planning because if you buy too small a PBX and fill it to capacity, you have to buy another PBX with another 5 year payback when you may only need a few extra lines. VoIP doesn't have this problem.
Cisco bought a VoIP software company a few years back and has open sourced all of the software necessary to setup a VoIP solution on your own. The website is vovida.org. Also, O'Reilly sells a book (referenced on the vovida.org website) that describes how to use vovida.org to setup a solution.
You will still need to buy some hardware. VoIP phones or VoIP phone software will be needed for the new building. VoIP phones are between $200-???/unit. The phone software is cheaper and essentially gives you a softphone. There are free softphones for linux, for windows, you can purchase them for under $100 I believe.
I don't know how difficult to setup the free voip software is, it is probably best to pay someone to support a solution for you. Be sure to shop around, we encountered many subpar vendors. Also, PBX solution providers get pretty cooperative when you start talking about VoIP. It really depends on how many phone lines you require and what your future plans are. If you planned on upgrading your data network or expanding, VoIP can fit nicely into those plans. But if you only need to add 10 phone lines, then it would seem kind of drastic unless you are going VoIP company wide. Since we lease all our lines and want to upgrade our data network anyway, VoIP will save us alot of $$$. The quicker payback also saves us alot of $$$. The scalability also saves us alot of $$$. We can just buy what we need.
You just need a way to get a few lines over a wireless link from the sound of it. I hope this helps a little.
Maybe you could patch something together from vovida.org for those few lines. Check it out.
If you only need two or four ports, grab a Cisco 2600 of 1750 off of ebay, throw in two of four FXO ports, and connect the FXO ports to the extension ports on your Lucent switch. Set up SIP on the IP phones in the "remote" office, and Bob's your uncle. Keep in mind that the Lucent Partner II requires switchhook action to transfer calls, and answer a second line. Using an IP phone might make that a bit difficult.
If it were me, I would run cable.
If you can't figure out my address, just drop me an e-mail and I will explain.
Depends, if they've switched off WEP and secured it with IPSEC, you should be waiting for perhaps a decade or two.
-WolfWithoutAClause
"Gravity is only a theory, not a fact!"I love wireless as much as the next guy (probably more since it has made me quite a bit of money), but if you are talking a 200ft run across the parking lot (probably your own parking lot, right?), then there is a LOT to be said for running a little piece of conduit with a couple pieces of fiber in it. Your workers will likely not be happy running VoIP and the network over consumer grade 802.11b equipment, not to mention the headaches that you will face with QoS or interfacing the IP phones into your existing system.
Unless you plan on replacing your entire phone system, you're probably going to have problems interfacing the IP phones with your existing stuff, and even if you can do that without trouble, you're going to get really stuck when you put it all on that 802.11b link and start having problems. By the time you get enough *good* wireless hardware and routers to handle the link properly, you'll have spent an awful lot of money. Also, as others have mentioned you'll have problems meeting fire and safety codes without land-lines over there anyway, and building-to-building calls would be free with local phone service anyway.
Anyway, my main point is that in the long run, it will not be cost effective to bridge the parking lot with wireless and VoIP versus a buried fiber "extension cord" type setup. If you were a mile away or running across a major street or something, it would be highly cost effective.
If you decide to go for it anyway, here's a couple of suggestions:
1) Don't think VoIP phones. Think VoIP bridges. A couple of channel banks on either end of whatever network link you have should allow you to interface remote phones directly with your PBX. Contact your vendor about it. Hint: Don't mention wireless; say ethernet and fiber instead. Adtran has some inexpensive stuff in this arena.
2) Don't think 802.11b. It's not going to cut it. Get something along the line of the WyLAN or Proxim equipment that's designed to be a point-to-point ethernet bridge. You'll get performance almost an order of magnitude higher than 802.11b with a something like the 12mb proxim system vs 11mb 802.11b. This is a very important consideration. Do not ignore this suggestion.
3) Put real routers at either end of your bridge. Do not rely on crap 802.11b linksys network bridges or something similar. You will need real routers to do the very important job of QoS. If you have voice running over the network, they MUST be able to properly prioritize all traffic. All of the inexpensive consumer wireless products that advertise QoS will likely be unsuitable for your applicaiton. Get some cisco equipment on either end and be happy.
~GoRK
Anyone know where I can get some 802.11 cordless phones? The only ones I can find are made by Symbol, but I know there has to be more out there.
In addition to Symbol (as you mentioned), Spectralink makes 802.11b wireless IP phones as well.
Cisco's 7920 Wireless IP phone will be coming out end of 1QCY2003, but out of the gate will only be supported in a Cisco CallManager environment. The Product Manager did a presentation a few weeks back here in STL, and the plans they have for the product are pretty neat (again, assuming you are in a CCM environment).
I plan on using them with Asterisk [asteriskpbx.com] and my 802.11 access point.
I'm using Asterisk at home as my IVR & Voicemail System, with Cisco's IOS Telephony Services (ITS) handling the actual call switching. ITS can scale up to 48 phones depending on the Cisco router platform you have. I'd actually prefer to us Cisco's Unity product as my IVR & Voicemail--but frankly, I'm too cheap to introduce that at home. Asterisk is, as you know, zero cost.
I like zero cost.