Do-It-Yourself VOIP Telco 246
DamnYankee writes "Robert X. Cringley predicts the coming demise of the landline telco monopolies from the grassroots encroachment of VoIP and Linux on the latest generation of Wifi routers. According to Bob, 'The result is a system with economics with which a traditional local phone company simply can't compete'. With Linux capabilities and builtin VoIP any Mom and Pop can become the local equivalent of a cellular phone company for the price of $79 Wifi router. Now how is Verizon going to compete with that? Get the full scoop from the man himself."
Interesting but is it ready for Prime Time? (Score:5, Informative)
Take care!
Erick
VoIP isn't that easy (or: You need more bandwidth) (Score:5, Informative)
Remember, ADSL and cable are asymmetric. That upstream bandwith is usually 256-384k. Each VoIP call is going to take anywhere between 24 and 64k of that just for the audio. Add on to that the administration overhead (UDP/IP and whatever stream management protocol you're using), and it starts to chew away at your bandwidth.
Additionally, the connection you've got is designed for bursty traffic. VoIP is most definitely NOT bursty (unless you use silence suppression, which I've yet to see a vendor get right). If you packet delay gets over 150ms, you're going to be upset. Jitter larger than about 50-80ms is going to screw with your call quality. I've done VoIP networks, and can attest to the catestrophic effects of just a small amount of jitter when you start to get near your 150ms limit.
Don't get me wrong: VoIP is here and going strong. But it's doing so in high-quality networks that can afford to supply fixed-bandwidth reservation, , not commodity broadband products.
Re:Ahem... (Score:3, Informative)
At the moment the design is that somewhere the connection has to have a broadband connection to interface to the Internet. The software upgrades to these routers allow that connection to be as many as three "hops" away. The possibility is there to reach longer, and even cross more hops, however such a connection requires added cost for improved antenas.
In the future, (how long is obviously a subject for debate) it is possible that a large enough population of the Internet will be attached to wifi connected equipment that people very well may be able to perform most, if not all, of their day to day network usage without actually sending any packets over the existing Internet structure.
Note that I am not saying this will be a large portion of the Internet population. I am not saying that it will be infinately secure, or even that it will happen. Just that it is a possiblity.
-Rusty
Re:Verizon will compete... (Score:4, Informative)
Re:not gonna happen, the lobbies are too powerful (Score:2, Informative)
Um? The telephone network has been packet-switched for decades. Do you own or work for a small business? You don't have phone lines. You have a T-1. At your home, your phone line goes to a box down the block where it gets muxed into a T-1 or something equivalent.
Re:Verizon will compete... (Score:5, Informative)
This all reminds me of a Grou Telecom outage a couple years ago. They lost a core IP router. Guess what happened to all of their VOIP stuff? That's right.. all down.. We had to contact our sales rep by her cell phone because their helpdesk was dead.
Right now I'm not seeing VOIP as anything more than a way to cut down on my long distace bills.
Re:Correct me if I am wrong ... (Score:3, Informative)
QOS, and Cable television (Score:5, Informative)
First off, the minute you go from a VOIP endpoint to the POTS phone system (you know, to route calls to legacy landline equipment) you are then classified as a phone company. This is where the tarrifs come in. This might not be the case if you just went from VOIP to Cellular, not 100% positive.
Next up, while the Vonage/Packet8 endpoints work well, it can be a pain deploying a reliable VOIP network. Qualtiy of service is a must, because a large email with an attachment can totally take out audio in one direction for a few seconds.
VOIP is neat, I think it will seriously cut into the long distance profits, but *I* firmly believe wireless phones are more of a threat to landline POTS service. I think the phone companies need to replace the legacy ESS5a switches with something newer, capable of dropping 50mbps to each copper customer.
Personally I plan to move my phone lines to a message rate service, it's incoming only landline. I believe it is about $10 a month. This supports the excuse to have a PBX at home
Re:not gonna happen, the lobbies are too powerful (Score:4, Informative)
Sounds like you're confusing digital with packet-switched. A T1 is a 1.544Mbps digital circuit, often chopped up into 24 64kbps voice-grade circuits. That T1 that serves your local business is a dedicated circuit from your location to your telco office. Even if you're using that T1 for Frame Relay, or ATM, or TCP/IP, it's still a dedicated circuit from the point it leaves your premise to the point it hits the packet-switching equipment on the other end.
Plain Old Telephone Service (known as POTS in the industry) gets digitized after it leaves your handset and before it gets far into the local telco central office. For a business system, the digitization could be in the PBX. For a home, it might be in a box on the corner of the neighborhood. The usual conversion is to a 64kbps data stream. No compression, no packetization. When you make a call, it rides on a 64kbps channel all the way until it gets to the final digital-analog jump-off point. If you're calling cross-country, you are the sole user of that 64k channel for the entire time you're on the call. A given T1 will carry 24 of them simultaneously, a T3 will carry 672.
One of the biggest advantages of packetized voice (be it VoIP, VoATM, VoFrame Relay or whatever) is that using compression, silence supression and a couple of other tricks, an acceptable voice channel can use as little as 8kbps. You get much more efficient use of the bandwidth. But the general Public Switched Telephone Network doesn't do this - it's circuit switching all the way.
Re:802.11b/g is powerful enough? (Score:2, Informative)
Note that you need to keep the connection from the transmitter and the antenna extremely short because cable loses are very high at the frequencies used for 802.11. What this means is that you should put your router or wireless adapter up there at 50+ ft with the antenna connected directly to it. Then run your ethernet or USB cable back down to your computer(s).
A good high gain omni-directional antenna can make a difference. Just be careful about having too much gain as there are maximum legal limits for power (which includes gain from antennas).
Or better yet, get your amateur radio license and come join us for some real fun. We can use extremely high-gain antennas (like slot omni antennas) and enormous power for transmitting (although most people stick to less that 10 watts or so). Our access points go tens of miles, especially those mounted at 300+ft.
There are other options (Score:3, Informative)
Wifi-Box [sourceforge.net] is incredably stable, and offers many options, taht are also being extended.
OpenWRT [sf.net] aims to be very light, but allow you to add packages to customize anyway you want.
More info on the router can be found at Seattle Wireless [seattlewireless.net].
Re:not gonna happen, the lobbies are too powerful (Score:5, Informative)
Yup. The term you're looking for is "Time Domain Multiplexing" - TDM. Each channel gets a time slice of the circuit, just under 1/24th of the total. There's a bit of overhead. This 1/24th, or 64k is allocated *whether that channel is in use or not*. And while it's in use, the "user" gets all 64k of it. Even if the mouthpiece of the phone is disconnected and nobody's talking the other way - no use on the 'line' whatsoever - the call is still using the 64k channel.
Cell or packet switching is a different animal altogether. A given channel may have a certain bandwidth guaranteed, and may be able to use well over that guaranteed amount, depending on the technology and lots of other stuff. Your average cell/packet circuit is only firing cells about 10% of the time.
The TDM part of a data circuit puts a hard limit the overall bandwidth. If you've got a T1 connection to your ISP, you can't send/receive more than 1.544Mbps, even if the ISP's router can switch hundreds of Mbps and they have an OC12 to their next peer. And if the site you're communicating with depends on an even lower bandwidth connection - such as when a dial-up user hits your ftp server - then *their* circuit is the limiting factor.
Re:not gonna happen, the lobbies are too powerful (Score:3, Informative)
You're on the right track with this statement. "Circuit switching" is the means by which a T1 slices up it's capacity into channels (1-24 typically) and each phone call gets one channel. The information is digital by the time it enters a T1, but it's not "packet" data in the common use of the word. "Packet switched" data is different from channelized data in that a typical VoIP call is crunched into an 8-12k stream of data, then on-ramped to a data network. A data T1 (1.5MB) can carry nearly 1.5MB/12k*60% = 75 calls with narry a problem. Call volumes can go up further if there is silence on the line (pauses between words, sentences, person talking, etc). A channelized voice T1 can carry 24 calls, period. A data T1 carrying packetized information can easily carry over 3 times that amount.
Think of this slightly lousy analogy:
Each phone call can be represented by a garden hose of data. A typical T1 scenario is simply a bundle of 24 garden hoses provided by the telco. When you place a call, you're hooking your garden hose into one of the 24 made available to you and sending and receiving information.
A packet-switched network takes your garden hose and hooks it up to a box that puts your information into little water-balloons. Each one is colored based on the conversation, so you get blue, your neighbor gets green, etc. Instead of providing you a bundle of hoses, your telco provides you a conveyer belt to put your balloons on. The conveyer is the same size as the bundle of hoses, but you can cram a whole lot more balloons into the same space. The telco then uses the colors of the balloon to route the information on their end.
Re:Two Words... (Score:3, Informative)
How many people have land line + cell phone. Why can't they switch to VoIP + cell phone.
The 911 problem. Call the Police or Fire department directly.
http://www.arguscourier.com/columns/weaver/health
Re:I use VoIP today. This doesn't seem likely. (Score:2, Informative)
If you have a power outage, your VoIP vendor can just route calls to your cell phone automatically. You call your power company with your cell phone and get back to business. Vonage does this already.
On a side note, I think that the Cable nodes should have some sort of power backups like the phone system does--even if it is only good for a few hours. This would break the perception about the usefulness of the Internet during these types of situations.
My wife and I have cell phones, a POTS line for the house, and a Vonage connection. She uses the cell phone more than the house line, providing she actually had the cell phone handy. So far, Vonage has been great. I have not had enough experience with Vonage yet to think about disconnecting the POTS line yet, but eventually we might.
We also have 802.11G that I use throughout the house, and I can weakly pick up other 802.11 signals from other houses. However, the WiFi signals are not strong enough, or reliable enough for me to depend on them for phone usage. I cannot even play a good game of WarCraft or UT2004 over the WiFi, because the packets are too jumpy. Perhaps with some of the token handling modifications that were mentioned in the article this might be better, but I'd have to wait and see.
Re:big companies CAN change (Score:2, Informative)
Great PBX auditing document (Score:3, Informative)
PBX Vulnerability Analysis: Finding Holes in your PBX Before Someone Else Does [nist.gov]
Its a 60-page PDF that covers all of the features included in most PBX's that can be exploited and/or manipulated.
If you're a security engineer I HIGHLY recommend it. Even if you're just the company's Network Admin that's also responsible for the PBX, check it out. What a cool line on your resume? How about "Reduced company's monthly phone bill by XX% (thing BIG) via PBX audit" Nothing says "You're Hired!" better than that.(Hint: turn off automatic-forwarding by default to start. People config their work phone to forward to their house over the night/weekend, and their long-distance friends just call the company's Toll Free number and get routed to the employee's house. They chat, company picks up the tab. Also look into setting up SMDR or CDR (google for it) on the PBX, connect a serial cable to the switch, and do some simple call accounting to determine who's doing what on your phone lines all day.
The tin-foil hat wearers are going to flame me a new one, but really this is just like sniffing your ethernet traffic to see if people are goofing off on the web all day. Plus, you're not actually LISTENING to whats said on the calls, you're just logging that extension x1234 called 978-555-1212 fifty times in the last month. Maybe that's a legit call, maybe its their wife/husband and they're goofing off. Or hell, maybe you figure out that you're under-utilizing your trunks, and can get rid of that extra T1 without causing inbound calls to get busy signals, or outbound calls to not get an outside line. Tell the PHB's to roll the first month's savings into your bonus plan :-)
And, as a turnaround question, have people found that their PBX experience translates into small-mid scale VoIP gigs, and if so, how? With a decent amount of PBX (non-voip) switch management under my belt, is it worth doing the WRT54G VoIP setup for the experience, or should I just try to find a job at a company that's doing 'real' voip?
Re:not gonna happen, the lobbies are too powerful (Score:1, Informative)