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Voice Over IP On Wireless Mesh

Posted by timothy on from the network-is-the-network dept.

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."

8 of 109 comments (clear)

  1. Wireless VoIP isn't feasible yet... by mindless4210 · · Score: 5, Insightful

    With the addition of VoIP support, these mesh networks can now compete with the telcos on voice as well as data services.

    I would have to disagree with that comment. Yes, these networks can now provide voice services, but they cannot effectively compete. In reality, wireless VoIP is still being developed and will most likely not be of acceptable quality for another year or so. Mainly, latency is the biggest issue to be conquered at this time. I think until they are able to reduce latency times significantly in these applications, it won't be widely accepted. It's just too frustrating when theres a couple seconds in between speaking and hearing a response from the other person.

    Furthermore, while a mesh network can still carry a high data rate, the high number of hops to a wired connection from some locations along the network could make talking over VoIP rather unbearable. I imagine that on a larger mesh network you could experience latency upwards of 1000 ms.

    --
    Wireless News www.DailyWireless
    1. Re:Wireless VoIP isn't feasible yet... by JoScherl · · Score: 4, Insightful

      I really don't latency is the problem as much as it is making the technology easier to use for the average joe ( X-Lite is NOT easy to set up if you have router ).

      Does Joe have a router? I think not. Ok, thanks to DSL-Lines, at least here in Germany, many people get routers, but still I don't think Joe Average has one. The greater problem is that a) Joe dosn't know about it and b) he doesn't know anybody else who uses the same VoIP system. To make use from VoIP it would imho need one big company advertising these services, but I think the ISPs do not like VoIP 'cause it creates huge amount of traffic

    2. Re:Wireless VoIP isn't feasible yet... by aminorex · · Score: 2, Insightful

      Well, it's not like VOIP takes up any more bandwidth
      than PSTN. If I'm calling you on a VOIP phone,
      I'm *not* calling you on a PSTN phone. The difference
      in backbone traffic on the fiber is negligible, but
      the difference to my wallet is significant.

      --
      -I like my women like I like my tea: green-
  2. Quality by lukewarmfusion · · Score: 5, Insightful

    Compete? Maybe not. Remember when NPR discussed this and one of the callers started having problems - right in the middle of his praise for VoIP?

    That said, I'm anxious to find an inexpensive way to replace my $90 cell, $50 broadband cable, and $40 landline. If I can cut these bills down significantly (by using my broadband to provide my landline) I'd be happy. And I'd bet that most bill-paying consumers would be too.

    1. Re:Quality by YanceyAI · · Score: 2, Insightful

      They manage to allow us to consolidate those, along with the idea of the single multimedia device, then I'm happy. Very.

      --
      Can I bum a sig?
    2. Re:Quality by ytseschew · · Score: 2, Insightful
      You also need reliability. My cable modem usually goes out for a couple hours every couple months. This past week it was out 3 times while they did "service upgrades." On the other hand my phone line has been out exactly 1 time in 4 years and only because a telephone pole was knocked down right near my house. My power has gone out a number of times but that never knocked out the phone service. I can't even remember having the phone service going out at my previous location. Having my landline phone go down is so rare that it's like a surreal event. Until my internet service comes close to that kind of reliability I'll be sure to keep a landline around.

      - Steve

  3. corporate projects are anti-social by Anonymous Coward · · Score: 1, Insightful

    and by their very nature take more than they give

  4. Injecting harsh realities by PureFiction · · Score: 3, Insightful

    The code is there, the actual performance is going to be lackluster at best.

    Mesh networks suffer from scaling problems due to the overhead associated with ad-hoc protocols. All that flexibility and adaptability come at a price: efficiency, latency and throughtput all decrease as the size of the mesh increases (and even more so when you have popular / power law nodes attracting routes)

    Voice is notoriously sensitive to delay and to some degree packet loss. Sure, delay effects can be overblown (ATM anyone?) but you get a saturated mesh network trying to route voice and those multi-second round trip times are going to make your cable modem look like a T3.

    [You get losses due to interference, transient link problems, mobile nodes, sun spots, whatever, that cause delays at the physical layer (an ethernet frame takes a while to traverse the ether) which then affects all higher layer protocols: UDP packets can't be reassembled because a fragment is lost. TCP starts backing off too agressively. Retransmission timers get triggered adding to inefficiencies, the list goes on]

    Wireless and mesh networking in particular are very promising and useful technologies, but they are no where near the utopia that is often presented.

    Trivial DoS attacks, scalability problems, and compounded complexity all add up to make it a very volatile environment.

    Sure, this stuff will work, but only in very constrained configurations / environments.

    Maybe someday further in the future these dreams can be realized when we have robust MIMO software radios and intelligent network stacks that can adapt to such harsh conditions. :-)