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

[LWolenczak]

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.

Re:call your system vendor

[dreamt]

Well, I'm not sure what the Avaya Key system is, but I know that Avaya has a native add-in card for their G3 line, which handles native (avaya hardware) IP phones, as well as "softphones" (install Avaya software on Win2k machine, it acts like a real phone). The phones act just like a real extension from the switch side. It works fine from long distances (our dev switch is in Boston, we have a remote offices in Dallas and Miami who use IP phones over a T1) so probably would do fine over wireless ethernet. The phones even have a "mini" hub built in. Plug phone into ethernet, then can plug a PC into the phone so you don't even need an extra network port. Only annoying thing is that the phones need power (although they support Power over Ethernet) and have a massive power brick.

Again, I don't know what your phone system is, but this might work if it can support these phones.

Re:call your system vendor

[Strog]

A Partner II is an older small system and wouldn't support it. G3 is a massive setup compared to this. The major difference between Key and PBX is Key has a button on the phones for all the lines and PBX just transfers to virtual slots. A PBX could potentially handle hundreds of lines where a Key system would just choke.

The poster of the article is deal with a very small system here.

Agreed.

[Andy Dodd]

You have two options:
a) Hope that Avaya supports VoIP with Partner. I don't remember if it does. Back when I worked for Lucent BCS (Before it spun off to Avaya), VoIP was bleeding edge and Lucent was still developing their VoIP systems.
b) If Avaya doesn't support VOiP with their Partner systems, you'll most likely have to junk the Partner system and get a key system that does do VoIP.

a) is more likely, since I recall the Partner being reasonably expandable, albeit nowhere close to the venerable Definity - Its expandability has allowed the platform to survive for over 20 years and still be one of the best PBX systems out the. (Definity was one of the first implementations of hot-swappable hardware - Swapping circuit packs in/out of a running system was a favorite demo to customers when the system was first introduced.)

As another poster mentioned, the Definity (He refers to it as G3, which is just the current variant of the Definity platform) can be given VoIP capability. Not sure at what size company a Definity becomes justifiable - My company started at around 80-100 people at 2 locations and had a Definity, but that could be partly because of anticipated growth and the fact that it was a Lucent spinoff. We're now a part of a different large company.) We had direct dialing-by-extension between Warren, NJ and Columbus, OH via a VoIP connection. I believe we now have VoIP links to other company locations too.

on second thought.

[LWolenczak]

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.

Possible source

[Anonymous Coward]

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.

Re:Possible source

[tzanger]

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.

Long shot here, but I'd like to talk to you more about this. Can you email me?

Hardwire it

[ka9dgx]

Let's face it, the only reliable way to get the phone service there is good old fashioned copper (or fiber). While I could support the idea of networking via 802.11b for a non-critical service such as networking, you really want honest to goodness cabling involved when you need to call 911, etc.

--Mike--

Re:Hardwire it

[davidu]

He wants to connect to their voicemail/psuedo-pbx setup.

There's no reason they can't/won't be able to get a landline from the phone company for like a fax or local/emergency line.

Lots of offices have the occasional _seperate_ line for things like faxes, local calling and/or 911.

-davidu

Re:Hardwire it

[s.fontinalis]

If it's the sales staff occupying the building they'd like you to treat *every* call as important as 911.

Re:Hardwire it

[Dark Fire]

Good point. If the power goes out and the wireless equipment/VoIP phones are not on a UPS, the phone system to that whole building goes down.

Re:Hardwire it

[mosch]

Nearly all office phones stop working once the UPS on the PBX goes out anyway. If you need to call 911, the phones will probably be working, and if they're not, odds are good that every single person in the office has a cell phone anyway.

Re:Hardwire it

[Strog]

Avaya's small phone switches first line or two switches to analog if you lose power. You can plug a standard phone in or some of the phones have a pass through so you can plug a single line phone into it for 911. The Partner II mentioned is such a product.

Wireless VoIP

[Dausha]

So, what would it take to make this a wireless solution? Would regular 802.11 do it?

Solutions for Voice Over IP

[rjsousa]

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

Re:Solutions for Voice Over IP

[chefmonkey]

Check www.digium.com

Oh... and, uh... it's opensource, too. Bonus. /a

Wha? Huh?

[Anonymous Coward]

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.

What's with all this cabling talk? Never heard of a WAN?

Now, the people in this new building are going to need access to our phone system, a simple Avaya Partner II key system.

So how much would it cost for your phone co to hook this up?

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.

You want to become your own phone company? Besides the initial investment costs, do you have the money to hire someone on to babysit the phone system?

We're considering an upgrade to a real PBX, but we would like to do this without blowing the pension plan.

Are your employees aware of how little money you have? Seriously, if you are expanding at a rate that requires you to lease new office space across multiple buildings, maybe you have enough money to leave this to the pros.

We would like to having something scaleable, and open source, if possible. Any thoughts?

Yeah. Don't skimp on the communications.

Re:Wha? Huh?

[afidel]

Clueless person alert!

What's with all this cabling talk? Never heard of a WAN?

MAN not WAN and 802.11b bridges are a pretty good way to do this in a campus environment where ripping up pavement isn't an option.

So how much would it cost for your phone co to hook this up?

How much would it cost in monthly interoffice calls each month is the more important question

You want to become your own phone company? Besides the initial investment costs, do you have the money to hire someone on to babysit the phone system?

It's called a PBX and since the majority of most offices traffic is internal it saves huge cash over POTS lines.

Are your employees aware of how little money you have? Seriously, if you are expanding at a rate that requires you to lease new office space across multiple buildings, maybe you have enough money to leave this to the pros.

PBX's often have large upfront costs that can be prohibitive for a small business because the chasis are designed for a much larger size then the client needs.

http://www.linuxtelephony.com/

[pauldy]

http://www.linuxtelephony.com/

Re:http://www.linuxtelephony.com/

[jerde]

http://www.linuxtelephony.com/ [linuxtelephony.com]

Phreaks

[finity]

Calling all phone phreaks. Business setting up voip and opening it to anyone sitting in their parking lot with a laptop and 802.11b wireless card. If encryption _is_ used, you may have to sit a while. ;-)

Re:Phreaks

[WolfWithoutAClause]

Depends, if they've switched off WEP and secured it with IPSEC, you should be waiting for perhaps a decade or two.

Check out SpectraLink

[scrubjay]

www.spectralink.com

I used to work there and they have various solutions in the VOIP space and have equipment that talks to various switches with both wireless and (I think) wired VOIP phones ...

Re:Check out SpectraLink

[w1r3sp33d]

Great idea, diasy chain an extra access point or two in the new building and roam around with your SpectraLink phones (or your Ipaq with Cisco Aironet wireless card) and register with your Cisco CallManager cluster at HQ, hell I bet I could quote you at about 400,000$ (your pension to mine!) In all seriousness, has anyone used a SpectraLink phone off an Avaya? I have used a couple wireless phones off a Cisco system (including the Ipaq which seemed to need a little side tone adjustment) and I was surprised how well it worked.

Success Story

[Anonymous Coward]

A local business, not satisfied with the fairly meager loss in productivity when their wireless network is hacked, made a bold move and chose to make their phones depend on it too. A wise choice, this way their employees, when the network is down, really genuinely can't do much at all. Work is underway on a study that will somehow link the AC current to the wireless network. :-)

VoIP

[Dark Fire]

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.

wireless security.

[Dark Fire]

The security of your wireless network is essential. You have to linux routers setup at either end. You may have done so already, but don't depend on the WAP builtin to the wireless cards. It is easily circumvented. You strong encryption on the router-router connection. Perhaps obvious, but I would rather state the obvious and be sure you are aware of the matter.

Re:wireless security.

[Dark Fire]

Sorry about the bad grammar, I was editing my posts alot.

You have to linux routers ==> You have two linux routers

You strong encryption on the router-router ==> Use strong encryption on the router-router

etc.

Cisco FXO Card

[legend]

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.

Re:Cisco FXO Card

[doogles]

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.

I am bumping in to this right now at home. I have local service from Southwestern Bell, which I terminate in a VIC-2FXO in my Cisco 1750. I am using Cisco's IOS Telephony Services to switch calls to a handful of Cisco IP phones. Of course, I have Call Waiting.

My Call Waiting beeps, and I have no way to send a hookflash to the PSTN from an IP Phone.

I was informed that a softkey with the ability to "send hookflash" will be coming to ITS around February of 2003. This will meet my needs, and people in situations as you describe. (assuming they are using ITS)

In Cisco IOS, Hookflash Relay does operate propely in an FXS-to-FXO setup; so it works from my cordless phone (hanging off of a VIC-2FXS).

VoIP Bandwidth and Leased Line Alternative

[jpkazarian]

Something to keep in mind: For real time speech quality, wireline TDM bandwidth = 0.15 * IP Bandwidth. Meaning that a 100 Mbps Ethernet link can support approximately 10 T1 lines worth of voice calls (120 simultaneous full duplex conversations). This is based on Ethernet realizing a 33% average throughput on shared media plus allowing 100% headroom for equivalent quality after IP packetization and quantization.

If the throughput of wireless Ethernet is the same as wireline, and by throughput we're not talking about the burst speed of the link, then an 802.11b link should be able to support one T1 worth of voice channels, or twelve simultaneous conversations. If RF interference reduces the throughput, your mileage may vary.

Another alternative is to lease a T1 qualified two twisted pair copper line between the two buildings from the phone company. Other posts are mentioning using channel banks at either end of the line. With leasing, the cost and pain of digging et al belongs to the local phone company. It may be worth the monthly rate for 100 feet to avoid that.

Cordless?

[WolfWithoutAClause]

Depending on how big the parking lot is, you may just need to install a cordless phone.

Or, if the call rate is low, a cell phone could work...

QSig

[ZenJabba1]

Don't go the hard way.. Just set up a QSIG link into your favourite Cisco router and bind the GRE tunnel between the two QSIG links over the WAN or LAN via whatever method you choose.

I have installed around 40 PBX PBX systems this way and its so easy because all newish PBX systems support QSIG

wildcard

[zogger]

--note I am talking out of my nether regions here. My thought is, is there some way to use a precisely aimed laser to carry the traffic rather than a broadcast radio solution? Please excuse if this is incredinly lame, it is outside my area of expertise. Just thought I'd throw it into the discussion as perhaps someone who is aware of this technology might expound on it to a small degree.

Re:wildcard

[pfelipe]

Check out http://www.terabeam.com/

From the page:
Terabeam's 1550 nanometer FSO and 60 GHz MMW systems deliver carrier-grade performance, flexible and quick deployment.

Bandwidth: FE, OC-3/STM-1, OC-12/STM-4

802.11a

[pci]

Well if your going to go wireless between the buildings, you might as well spend the extra couple hundred and use 802.11a. The spectrum is much less used.
As for the VoIP solution, look at shoreline [shoretel.com], they have a nice selection of VoIP solutions that use standard analog phones as well as soft phones.

Re:802.11a

[duplicate-nickname]

Negative.... 802.11a does not allow for external antennas.

Re:802.11a

[Oculus Habent]

perhaps 802.11g - though availability is a bit of a pain right now...

Hardwire

[GoRK]

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

Re:Hardwire

[afidel]

Why wouldn't 802.11b cut it? I guess it might not with cheap gear but with Cisco bridges it shouldn't be a problem. They have QOS et all. I use a softphone from my laptop all the time with no quality degredation at all and that is with roaming and everything else. With fixed bridges it should be stupid simple. On point 3 you are right but your probably thinking of a router not AP's but the AP's should be able to do everything fine.

Multitech's MultiVOIP

[no_such_user]

For a linux-centric solution, check out the VoipBlaster [creative.com], or more specifically, voip.ring.org [ring.org] and Fobbit [fobbit.com].

For a ready-made setup, checkout Multitech's [multitech.com] MultiVOIP [multitech.com]

These units aren't the cheapest VOIP solution, but among the easiest. They come in FXO and FXS flavors, which means (check me on this) you can hookup one end to a phone company provided POTS line (FXO?) and extend that to a remote location (FXS?), or hookup one side to your PBX and another to a POTS phone at the remote office (both FXS?), or PBX-to-PBX (??), or whatever.

The have a demo [multitech.com]. You call a toll-free number which rings into a MultiVOIP device co-lo'd at some ISP in Chillicothe, OH (I've been to Chillicothe - it's sufficiently remote to convince me that it would work beautifully over a half-decent connection). That device connects you to a (very nice, I might add) sales rep at Multitech.

Re:Multitech's MultiVOIP

[Strog]

I was going to suggest these products. I used to be the network guy at an Avaya provider and we used to use these for VOIP. It was great when you needed a couple lines, extensions, etc. remotely. Most vendor solutions are expensive and centrex was more expensive and limited.

Another great product but probably more than you want to hook up to a Partner II is the MCK [mck.com]line of products. We hooked up MCK up over a wireless ISP to a cable connection and used the console phone on the remote end without any problems. Of course the quality of this particlar connect meant you wouldn't want to have more than a couple simultaneous calls but it was enough to convince customers that their T1 should be just fine for bandwidth. They have setups for several different vendors of phone switches.

O.T.
There is a movie that you reminded me of when you mentioned Chillicothe, OH. It is called Chillicothe and is available from Hollywood Video for rent or from the website [blueyonderfilms.com]. It's pretty funny.

Which way to skin this cat...

[voip guy]

I have implemented over a dozen different VoIP systems and I can tell you there are as many different ways to do it as there are vendors. MCK, MultiTech, Spectralink and others all offer various ways to get it done. One thing I have seen over and over in homebrewed jobs is this- they usually don't work because people try to put too many devices in the path. If you go over 100ms of delay your call is hosed. I have done VoIP over 802.11b for a national logistics company with awsome results. I can say this- you get what you pay for. Avaya is presently light years ahead of NorTel in this arena for sure. How many people are you trying to connect? Do you want feature transparency across the link or just dial tone? Do you want wired or wireless phones? There are many things to consider. If you are thinking of a nex PBX altogether- look at the Avaya IP Office. $$ per user is cheap and funcitonality would have cost 4 times as much just two years ago. IMHO.

Re:

[account_deleted]

Comment removed based on user account deletion

Re:802.11 cordless phones

[doogles]

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 [spectralink.com] 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 [cisco.com] 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 [cisco.com] (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 [cisco.com] 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.

Re:

[account_deleted]

Comment removed based on user account deletion

Re:802.11 cordless phones

[doogles]

I thought Asterisk could handle the call switching itself? Is this not the case?

Sure, it can. I'm not interested in using it for that, for a number of reasons.

Asterisk seems geared towards leveraging Linejack and Phonejack, which would mean additional investment and usage of plain old analog phones. (Most) analog phones lack the "oh cool" factor of a Cisco 7960G IP Phone, which I already owned. This was just my take--I don't really know for sure. I'm much more comfortable with Cisco gear than Asterisk.

The only negative to Asterisk is that you need a plugin to support H.323; it's not supported out of the gate. I used asterisk-oh323, which I found on Freshmeat (after a LOT of searching on Google).

Check out Altigen

[minister of funk]

I know you probably have a substantial investment in your present phone system; but I think you should check out Altigen here [altigen.com]. We have an Altigen system managing communications in our office. Our sys admin dropped a couple of VOIP cards in the box for long-distance communication with remote offices. Granted, the remote office needed a matching VOIP card, but any phone in our office, when dialing certain extensions, became VOIP phones. These phones are standard phones, too.

I'm pretty sure that your local telco can set up a "hardwire" connection between your two offices. I'm not sure of the terminology anymore, but I believe it to be exceptionally reasonable.

But, c'mon, have you considered the benefits of having cable draped across a 100' span? Christmas lights, anyone?

GNU Gatekeeper

[willamowius]

If you are using H.323, get the GNU Gatekeeper [gnugk.org], also known as OpenH323 Gatekeeper.

I can see it now:

[Hard_Code]

You. Have. Thirty. One. Thousand. Three. Hundred. and Thirty. Seven. Messages. Last. Message. From. "HAXXOR" At. Two. AM. To. Hear. Message. Press. One.

Linux + voice modem = cheap VoIP?

[matt_wilts]

I'm really surprised that no-one has come up with a system where you can basically "extend" a phone's reach, using 2 Linux boxes & 2 voice modem cards.

Or have they, and I just haven't found it yet?

Matt

don't do it captain

[why_me_why_my]

We use VOip in my workplace, which is a place of constant customer service phonecalls, and the problem with VOip is that it sounds like digital garble most of the time. We're constantly having 2 call people back on the "land line" Don't do it, for your own sanity and those of the other employees!