Voice Over IP On Wireless Mesh

infractor writes "ZDNet is reporting that the Linux based LocustWorld Mesh system now has SIP routing at every node. The LocustWorld boxes have been widely used in community broadband projects where DSL is not available, so successfully that they have been seen as a threat to next generation mobile networks. With the addition of VoIP support, these mesh networks can now compete with the telcos on voice as well as data services. More details here."

Comments

Re:Wireless VoIP isn't feasible yet...

[BlueShad0w]

And on top of that, the idea of technically free VoIP calls won't go down well with the sevice providers. I can't imagine them NOT lumping enough service charges on top to make it totally unfeasible to home users, whereas the 'read more' article seems to be aimed at just those people.

Let me stick with my MSN (*awaits flames*) voice conversations with people I know

This is precisely

[iminplaya]

the kind of "wireless internet" that I have been babbling about in other threads. This is what can liberate us from corporate control of internet access. I want to see this "wireless cloud" cover the planet. The latency issues will be worked out. In the meantime, this is great for "little" community internets where latency is not that bad. Even if they can't access the net at large, they can communicate, completely free from interference from the gov't, with each other. Maybe (hopefully) it can bring about completely anonymous, untracable communications. Just because it's not codified into law, anonymity is a right, and anything that can bring it about is a good thing.

my greatest dream

[ericbrow]

I've always thought that this should be. Wouldn't it be great if wireless networking were as easy to come by as electricty, but without the wires.

I know it's a little communistic in thinking, but I really believe that to gain true freedom of information, we need to make the information superhighway free to use.

While I know many problems would have to be worked out, like security, but it would change everything. Imagine every student being able to turn in assignments anywhere. Imagine doctors being able to monitor patients real-time, as they were being rushed to the emergency room. Yes it would put the telcos and cable companies in an uproar. But I think that would be the price of progress.

So..

[bigattichouse]

question is, will it "all" eventually be one big mesh out there? I imagine the telcos will do what they can to stop it, but I could see mass mesh adoption as an incredible force to recon with.

Re:Wireless VoIP isn't feasible yet...

[PretzelBat]

So long as this is internet to internet there is no service fee.

However, this sort of thing, if it becomes common, could quite possibly lead to a tragedy of the commons. If everyone actually started using all the bandwidth they had available, the networks would become jammed quickly enough.

Free VOIP is great in the short-term, but there is *not,* at this point, an unlimited amount of free bandwidth available.

WVoIP taking over Wireless (Mobile)

[UID1000000]

I've been thinking about this same thing just recently. From what I understand http://ask.slashdot.org/article.pl?sid=04/04/13/20 43202&mode=nested&tid=126&tid=137&tid= 215 that VoIP still isn't the most reliable thing in the world. There are a few things from a business stand point that will keep WVoIP from overtaking the mobile market, although this is perfectly tempting.

Here are a few of the reasons:

• The number of flaws and hacks that are readily available for switches, routers, and hubs and the fact that the OSes that run these appliances are too vunereable (think M$).
• The fact that the system isn't proprietary. I understand that there are ways to make a wireless network prop by MAC translation, etc.
• Handsets, currently there aren't any handsets available nor anybody in the market who wants to make them

Well, these are just a few thoughts. I know that there are many other insights as to what might make this industry grow.

Currently, to me, it seems like a lot of the open public widespread wireless networks tend to be international countries (not America) and they tend to be home grown by some geeks.

Represent a business model that would cost billions to setup and would still have to have willing hardware developers to make it happen and let me know what capital investors are interested.

Re:WVoIP taking over Wireless (Mobile)

[UID1000000]

Good point to each of those items.

What about hardware? I'm talking about load balancers, servers, and phone sets? Let's suppose you roll something like this out to a community, what would they have to have to support it? Probably a server with a 1Gb backbone right? Something to handle all of the traffic too. Then they'll need hardware for the phone replacement.
Or it could be offered as a notebook/PDA based software that you use to make your calls.

voip in actual use

[Anonymous Coward]

VOIP is great, but outside the cities it really
doesn't cut it. That's where the market is though.

I've used some VOIP implementations in less than
ideal conditions and there is a lot of work to
be done before this is ready for prime time.

Not a coder ? Want to help spread Linux ? Click here !

Re:Wireless VoIP isn't feasible yet...

[LOL WTF OMG!!!!!!!!!]

I agree with you on most of that. However, MANY people have routers. Essentially anybody who has a broadband line and more than one computer.

And routers these days are generally easy to use. CompUSSR sells one for $20 with a nice web interface and very easy instructions.

However, the fact remains that most VoIP software has horrific problems when working with a router. Whether this is problems with most routers handling UDP, or just bad programming is something that's beyond me.

Wireless vs. Fiber vs. Commercial vs. Govt

[billstewart]

Wireless clouds are cute and friendly and don't have really huge bandwidth (though I'm one of those old-timers who remembers when 56kbps *was* really huge bandwidth :-). Fiber optic pipes *do* have really huge bandwidth, and most of the locations you want to talk to are connected to them, and if you want your community wireless network to do anything useful, you're going to need to tie them together, typically using the wireless for local access and maybe cross-town access and using ISPs for long-haul backbones. You might tie into them by buying big-ISP service at some points (e.g. if you're a non-zero-cost cooperative), or community members who have friendly DSL ISPs like Sonic and Speakeasy might share their bandwidth, or you might be part of a commercial local wireless net such as Sonic.net's Sonoma County rooftop networks. The more complex and mobile your network, the harder it is to get routing right.

Interference from the government is a relatively orthogonal problem. There are several different kinds you can run into, including

• Government-run or government-mandated private companies providing local telecom or cable services that restrict what you do with your access. Wireless access that doesn't use these services usually avoids this problem, though you're still connected to a longhaul provider at some point. In some countries, it's not that easy - even though most of the world has "telecom liberalization" now, there are still usually some restrictions on competing with The Phone Company.
• Government-mandated fees (like Universal Service Gore Tax, access charges for the privilege of connecting your phone line to long distance (even if you only use it for DSL, not voice), etc. that you avoid by not using the government-supported telcos as access providers.
• Wiretapping on your data connections: Wirelesstapping is often easier to implement, but wiretappers know where the phone company buildings are, and can often bully the telco into implementing the wiretaps and passing along the cost in their rate base. Either way, if you don't use encryption, you're tappable. The US FBI is trying to expand the current regulations that let them wiretap voice calls to cover all ISPs as well as traditional phone companies, because they want the expanded power, expanded lack of accountability, and ability to force other people to pay the costs of their habit.
• Even if you're using encryption, wirelesstappers (or wiretappers, if you're going somewhere far enough away to need wire) can show which IP addresses are talking to which other IP addresses. That means that unless you're using encrypted tunnels across the wired space, and/or changing your IP address for every connection in ways that aren't logged, you're not going to get much anonymity. Building Anonymity is hard work.
• Wiretaps on voice calls - if you're using a gateway from IP SIP space into the Public Switched Telephone Network, that gateway can be wiretapped just like any other phone call. The big difference is that the gateways don't have to be located in the same jurisdiction as you are, though for cost reasons they're usually located near the recipient. That means that if you're IP-phoning one of your non-IP-telephony-equipped neighbors to plan next month's anti-war protest, your local police Red Squad can get a court order to wiretap your neighbor's phone, and John Ashcroft can get an unaccountable back door into the VOIP gateway in your area code -- but if you're IP-phoning one of your friends in another state to come speak, your local police can't tap you, because the gateway isn't in their territory, and they probably won't do the paperwork to get a tap on your friend unless you call them a lot. If you're calling somebody in Palestine to come speak, the NSA / GHCQ Echelon wiretappers might be listening, and Mossad or Shin Bet might also be listening, but that's both on the far end.
• .... many other forms of interference I haven't thought of - add your own ...

Like Air Supply, this could be big in Asia

[pangian]

The only place that my organization considers VoIP is in our offices in developing countries.

In many developing countries landlines simply aren't a viable option due to underresourced, corrupt and/or incompetent state-owned telecoms. Many of these countries have been able to develop more robust cell and broadband services, as these industries have seen less regulation and are more scaleable.

For security, convenience and efficiency reasons we like to provide staff in these offices with cell phones, however cell phones plans in may still leave much to be desired in some countries.

I think that many of our offices would be interested in VoIP cell phones if the coverage was decent (even covering major cities might be > or = to existing cell networks). Latency in phone conversations is already par for the course.

Could be an interesting microenterprise project.

Re:Wireless VoIP isn't feasible yet...

[azuretek]

I work for a cable company, I'd say about 70% of the people that call have routers even if they only have one computer. Most people with routers dont know exactly what they do, in fact that's probably the reason there are so many unsecure access points.

VoIP has companies advertising and it's becoming more popular as well as usable.

Re:Reality Check

[PureFiction]

I'll shut up after this, promise. :-)

Multisecond RTT doesn't happen on anything but GPRS

I've seen it far too often on congested wifi networks. you easily get into a congested state with a crowded AP that forces lots of client waits for the DCF (i.e DIFS + padding, each in turn) and also induces lots of retransmission at the physical level due to collision with so many clients trying to talk to the same AP. Low power clients associated at the 1 or 2 Mbps rates drive this contention over the DCF even higher, severely punishing everyone associated.

The big conference venues are notoriously bad about this, as you often end up with 10-20+ people associated with a single access point. That is just too many, and the 802.11 MAC was never meant to handle that kind of load efficiently. It is a pretty good solution for the general case that simply can't cover all the edge cases (long shots, high client loads, noisy RF environments).

This type of situation results in really weird ping times, for example. I've seen fluctuations myself that go from 80ms, 120ms to 3s!, 2s!, etc. then back down to a few score milliseconds. That is the 802.11 MAC trying to cope with scenario's it was never designed to encounter.

I mentioned software radios in the first post because having access to timing and congestion control in the MAC would allow mesh boxes, clients, and AP's to make very significant performance enhancements for situations where they were needed. Why be forced to use a static, inflexible, proprietary hardware layer when you can have the open flexibility associated with software radio? (It's coming, just not soon enough :-) There are also extensions to the ad-hoc routing protocols (like passive monitor of route info between other clients in DSR) that could be supported if only the hardware was open enough to do so.

I don't want to bitch too much; we have come a long way from sub-megabit data via FHSS over 900Mhz. I just want the really good stuff to hurry up and get here already so that things like mesh networks, low latency/loss voice over IP, and highly available multipath/redundant network configurations can be enjoyed to their full potential. (software radio + multiple input / multiple output + intelligent network stacks that can handle a diverse and volatile network environment). ... and a pony!

Gratuitous links:
congestion problems at TechEd conference

congestion melt down at CeBIT

GNU Radio's software defined radio (SDR)

software defined radio on $2,000 of 'roids [it's a dev kit, but would work very well for almost any kind of project]

Re:Reality Check

[Effugas]

Wow. Very cool. I was unaware of this particular failure mode for 802.11. I would have assumed that the exponential TCP backoffs would have slowed down the incoming packet rates enough for the system to eventually slow down to some reasonable rate ... I bet, to some extent, hidden node played a _big_ factor here too.

Still, I'm amazed you saw not dropped packets, but the MAC hold onto stuff for thousands of ms. Wow.

You know, the newest Linux wireless drivers have moved _everything_ into software -- thus the ability to throw up an AP on demand. I've actually got an amusingly demented protocol hack that would address some of these shortcomings, quite transparently...any interest in collaborating? Send me an email.

--Dan