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VoIP for Deployed Soldiers? 362

Posted by Cliff
rickbassham asks: "With VoIP really catching on these days, I decided to look into it for keeping deployed soldiers in touch with family and friends. I am currently a soldier in Iraq, and have the ability to get satellite-based internet, thanks to a few of the locals. While individually it is prohibitively expensive, a group of soldiers can come together to purchase a decent-to-high-speed internet connection. One of my plans is to link other soldiers to Vonage or another VoIP provider, so they will be able to keep in touch. Understanding the latency issues with VoIP via satellite (not to mention the other disadvantages), what upload speed does Slashdot recommend as a minimum for a QoS enabled connection for about 15-20 soldiers? The same for a non-QoS connection? What recommendations do you have for a good VoIP provider?"
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VoIP for Deployed Soldiers?

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  • by garcia (6573) * on Tuesday February 15, 2005 @05:05PM (#11682516)
    I don't know about this particular solider but I have had no problems contacting three friends that were/are deployed in Iraq via the Internet. One was on AIM for 45+ minutes a day and another is on AIM for several hours a day. The third isn't quite as Internet saavy but routinely sent emails and pictures at least weekly. Granted they aren't on 24/7 like we are here but I had no problems contacting them via the Internet.

    I would like to know if I was experiencing something that is unusual for military personnel deployed overseas? I mean this guy makes it seem as if he's hanging on to a rope thrown to him by the locals. From what I understand from the one guy I know that just returned from Iraq the locals over there want absolutely NOTHING to do w/the military personnel stationed in the desert.

    I also know that phone calls were routinely made to his family and to another buddy that is stationed in the States. Why would they need VoIP and why would they need to do it via satellite connection?

    As this guy said, sat-based Internet SUCK HARD for VoIP being that it is so latent. That wouldn't exactly make for real-time conversations regardless of how clear the voice might be... I have run the testers that other slashdotters have linked to before (sorry don't have it on-hand right now) and my 256k upstream seems to rate just fine. I haven't actually used VoIP though so I really couldn't tell you and I certainly couldn't recommend something to handle 15-20 people simulatanously (if that's what you mean).
    • by pilgrim23 (716938) on Tuesday February 15, 2005 @05:15PM (#11682649)
      Seems to me, "talkin to the folks back home" has always been a function of aid organizations like USO, or of the Army itself. Soldiers needing to BUY time to talk to loved ones seems a terrible solution. Our soldiers are already putting life on the line, (and for lousy pay too one could add). In older conflicts the two things that armies KNEW you could NEVER be mucked with was 1 Chow and 2 Mail. Seems in today's world this would fall under catagory number 2. Also, in WWII at least; letters to home were free, no stamp.
    • I thought communications by soldiers deployed in war zones were censored. By every country that has been in a war since The Art of War was written. The chain of command might not look too favourably on soldiers using non-official channels, even to say "Hi mom, I miss you".
      • No shit, how did you think the Abu Gharib photos got traded? On the internet, from Iraq, with love.

        Don't give these soldiers too much credit for being security-minded, most of them are 18 year old kids, fresh out of high school and straight out of the boot camp. The internet is one of the best and worst things for soldiers to have access to. I'd hate to be a military sysadmin.
        • No shit, how did you think the Abu Gharib photos got traded? On the internet, from Iraq, with love.
          Actually, according to Chain of Command: from 9/11 to Abu Ghraib, by Sy Hersh (the guy who broke the story), they came home with a vet. The wife found them on the computer and emailed them from the US. So it was sneakernet (air-liftnet?) until the States.
    • > From what I understand from the one guy I know that just returned from Iraq the
      > locals over there want absolutely NOTHING to do w/the military personnel
      > stationed in the desert

      Depends on where in Iraq you are. Iraq is a very divided country; in some spots, you're quite safe as a soldier (even an American soldier, although being a foreign soldier is better). In others, even leaving your base in an armored vehicle is risking your life. It all depends. But in general, yes, most Iraqis accordin
      • (even an American soldier, although being a foreign soldier is better)

        Isn't an American soldier a foreign soldier in Iraq?
    • I've successfully used Cisco's VOIP Communicator software running over a dial-up 56k connection (so thats 53k max down and 33.6k max up). It wasn't great quality, but it was tolerable.

      Jitter is definitely the kicker for VOIP, delay isn't that big of a deal. It takes some getting used to in regular conversation to have a >200ms delay, but I'd say anything under 1500ms could be tolerable with some experience.
    • by jonmansey (859749) on Tuesday February 15, 2005 @06:07PM (#11683253)
      I saw this post and felt I should reply to address some misconceptions about voip and satellite. As CTO of an Iraqi ISP http://www.tigrisnet.net/ [tigrisnet.net] who offer wireless broadband service throughout Baghdad and Basra, I have many customers who are like you, groups of soldiers who got together to buy a connection for their barracks.

      Our wirless broadband is fed by dedicated bandwidth over C-band satellite so the latency to our NOCs in downtown Baghdad and Basra is around 550ms but absolutely constant and reliable at that rtt, unlike VSAT services which are normally heavily contended and can indeed show wildly varying ping times in the 1000-2000ms range, indeed very bad for VOIP, either SIP or skype wont like that.

      Of course round trip time is twice the delay that will affect voice calls, as voice delay is only the "throw" from my phone to your phone for a RTP packet. So around 1/4 sec of one-way delay makes for very acceptable voice quality.
  • Skype (Score:2, Informative)

    by Raven42rac (448205)
    Skype [skype.com] No pesky service fees as long as all involved have accounts, or you can call for a low low rate, 1.7 Euro a minute.
    • by js7a (579872)
      1.7 euro a minute? That's absurd! Surely you must mean 0.017/minute?
    • $1.70 (euro) a minute is a "low low rate"?

      TelIAX, a Asterisk friendly VoIP provider, lists only $0.30 (USD) for Iraq.

      http://teliax.com/rates.html
    • Re:Skype (Score:5, Informative)

      by magefile (776388) on Tuesday February 15, 2005 @05:16PM (#11682652)
      1.7 Eurocents, or .017 euro. Not 1.7 Euro.
    • I've got to second Skype. Used it to talk to suppliers in mainland China with no problems. Free, works with linux, what more could you ask for?

      Just tell your friends at home to leave their computers on, and they'll hear it ring when you cal, just like a "real phone", but without the VoIP "solution provider" phone bill.

    • Re:Skype (Score:2, Informative)

      by merdaccia (695940)

      He means 1.7 Euro cents [skype.com] a minute. Although it's closer to 35 Euro cents to Iraq.

      However, do give Skype a try. I conference call with friends in Europe and Africa from North America and some of these people are on dialup. It works very well, and it's free if you're not calling an actual phone.

    • Re:Skype (Score:2, Informative)

      by snizfast (763637)
      The Skype client allows you to make calls across the Internet for free. Both you and your family back at home will need the client installed. Skype can work over dialup so bandwidth is not much of an issue. But the lag time to send the signal to the satellite and back would get ... well annoying. Another option that works back in the states is cell phones. Verizon for example gives free ISDN bandwidth Internet over its cell phones. I doubt that it is an option for most troops but I thought I would men
    • Re:Skype (Score:2, Insightful)

      Skype is your best bet if you're looking for free VOIP and don't need to call local emergency services. Currently telephones are the standard of voice communication. Unfortunatly, the general public is afraid of change. On top of that, multi-billion dollar corporations are reliant on people paying for voice communication and will stop at nothing to make people believe phones will be needed untill the end of time. This can be parallelled with oil companies trying to stall advancements in alternative fuel
      • " Skype is your best bet if you're looking for free VOIP and don't need to call local emergency services."

        I don't think the army is going to call 911.

        "Hello, is this the Iraqi police?"

        "yes?

        "Could you tell your buddies to stop lobbing mortars into our compound? We're trying to eat."

        "ummmmm....we'll look into it."

        • Hum, that would be mortar rounds. If the Iraqui resistance was lobbing actual mortars into american compounds, that would indeed be a good thing.
  • Latency (Score:3, Informative)

    by Talking Goat (645295) on Tuesday February 15, 2005 @05:08PM (#11682567)
    Latency on sat connections can be upwards of 900ms... I don't think VoIP is going to like that very much at all.
    • Re:Latency (Score:2, Interesting)

      by DaemonTW (733739)
      I've used a few different 2 way satellite links, latency is generally about 500-600ms for a round trip in the systems I used. Using the voice port in a Cisco router was quite useable, in fact I was surprised at how well the TCP/IP stack functioned with the high latency.
    • Re:Latency (Score:3, Informative)

      by Poseidon88 (791279)
      Latency is not a huge issue for VoIP. It will only cause a noticeable delay between when you speak and the person on the other end of the line hears you. The thing you have to watch for is packet loss. VoIP typically travels over UDP, which means there is no guarantee of packet delivery, so anything over about 5% packet loss can have a significant impact on audio quality.
    • Ditto that. I am collaborating on a project with a contractor in Iraq, and when he calls me we constantly overrun each other's conversations. I've taken to using the same protocol I used inthe MARS stations in Vietnam.

      (Over)
  • Latency (Score:4, Interesting)

    by shaitand (626655) on Tuesday February 15, 2005 @05:09PM (#11682572) Journal
    The latencies associated with a sat connection make voip over one impossible. As bad as latencies appear to be, the sat companies use a lot of tricks to reduce latency with normal web traffic. Those tricks will not work with streaming voice.
    • Aren't NORMAL call transmitted via satellite already? Or do I hallucinate...
      • not really, though there are satellite phones. If you've ever seen a news report via satellite you will notice the lag between questions and answers. Calls oversees go through undersea fiber optic links for reasons of bandwidth, price, availability and latency. Also repairing a undersea fiber optic line is trivial compared to repairing or replacing a satellite.
    • That's only true of geostat satelites.

      If you use a service like Iridium or Globalstar then you're dealing with LEO sat's which have much lower latency. They are probably only about 500km away.

      Unfortunately i've never seen a data service faster than 9600 on an LEO satelite - you'd struggle to get any VoIP over that.

      Given the huge per minute charges it'd make more sense just to use their phone service.
  • by selfabuse (681350) on Tuesday February 15, 2005 @05:09PM (#11682573)
    When you're talking about several thousand milliseconds of latency, all the bandwidth in the world isn't going to make your VoIP any better. If it takes 2000ms from when the packet leaves your VoIP provider until when it gets to you, no matter what you do, your conversation is going to have a 2000ms delay..

    unless I'm wrong, which I'm pretty sure I'm not, but if I am, please post back! I'm sure my VoIP customers would most appreciate it ;)
  • Satellite Internet has horrible latency, never mind the fact that it is also traveling half way around the globe. Vonage cuts out quite a bit as your latency increases, if it were 200ms per packet, that would be quite a delay and perhaps even borderline unusable.
    • by Skiron (735617)
      never mind the fact that it is also traveling half way around the globe.

      So cable connections go through it? That would explain...
  • Voip forums (Score:2, Informative)

    by markclong (575822)
    While I can't really comment on voice over IP as I've never used it I have read a lot about over the Broadband Reports [dslreports.com] forums [dslreports.com]. You may want to stop by and ask your question there.

    http://www.dslreports.com/forum/voip [dslreports.com]
  • Ping (Score:2, Interesting)

    by Anonymous Coward
    Google calculator:

    (4 * radius of Earth) / the speed of light = 85.1002062 milliseconds

    Don't expect shorter ping roundtrips.
    • Re:Ping (Score:3, Interesting)

      by uberdave (526529)
      That is misleading for two reasons. First, the signal does not travel through the planet, it travels around the surface. Second, your calculation is for sending a signal (and receiving an echo) from opposite sides of the planet. Should I not be able to expect a shorter ping time if I am pinging my next door neighbour? Google says: (10 meters * 2) / the speed of light = 66.712819 nanoseconds.

      This [usda.gov] might be a good starting point. Baghdad, Iraq to Washington DC, United States is about 9968 km, yeilding a
    • Re:Ping (Score:3, Informative)

      by Lawrence_Bird (67278)
      Well.. I could be wrong on this but.. I think the service
      he mentions uses Intelsat which are in geosynchonous orbits
      that put them about 35,800 Km away. Up and back puts it at
      71,600 Km, or about 0.238s or 238ms at light speed. As
      already mentioned there is additional lag for the entire
      system, hardware <-> satellite.
  • by IcEMaN252 (579647) on Tuesday February 15, 2005 @05:12PM (#11682609) Homepage
    Sat-Internet usually uses GEO satellites, so as you say its really not good for latency sensetive applications, ie. VoIP.

    But, if you're thinking about pooling resources, what about some type of satellite phone? Most sat-phones use LEO satellites, so latency isn't a problem. Its true, they are expensive, but if you are pooling resources, it might make it affordable and provide a better quality of service.

    Of course, I'm not a soldier, nor do I personally know one, so I can't speak to what's really reasonable there. Also, I'd be curious to know what regulations the military has about personal communications equipment.
    • The problem here is that the per minute costs are still very expensive, and VoIP wouldn't be.

      The latency isn't the end of the world, it is jitter that is really a concern. Geo satelites have been used for voice for a long time, and while somewhat anoying, are perfectly usable.
  • USCG (Score:3, Interesting)

    by Elvisisdead (450946) on Tuesday February 15, 2005 @05:12PM (#11682612) Homepage Journal
    Captains are issued Sat Phones. That's how I keep in touch with my buddy.
  • by lottameez (816335) on Tuesday February 15, 2005 @05:12PM (#11682618)
    Durn kids these days, and their conflabbed newfangled VOIP teknollergy.

    Back in the day, when I was stationed overseas, the cheapest way to call home was a service that was hosted by ham radio operators. We'd call up the local ham who would transmit to a us-bound operator who would make the local call to the family. It was always weird talking to your mother to say things like "How are you doing? OVER!" all the time.
    • This solution won't work in the future with the BPL psychotics actively trying to make the ham bands useless.
    • by dr_canak (593415) on Tuesday February 15, 2005 @05:22PM (#11682733)
      Actually,

      the shortwave community can still make this happen, and does. I live in Chicago. Using a Sony ICF 2010 shortwave reciever a couple years back I picked up a military transport over Newfoundland. The soldiers on the plane were returning from Afghanistan. They were communicating with a HAM in Iowa, who was then patching them through for 1 minute conversations to family to let them know their arrival time in Washington. Pretty neat actually, and purely accidental that I heard the transmission as i was running up and down the dial listening for interesting things.

      jeff
      • Isn't this exactly why this shouldn't be allowed, non-controlled open access communication lines cost lives (I expect) ...

        Soldier boy: "Hi Mom, can't talk now we're about to launch a top secret raid on Mizp'hak - those Iraqi's won't know what hit them"

        Iraqi General: "Don't call me Mom"
    • VOIP on a satellite link wouldn't be much better- to avoid cutouts you'd have to go half-duplex (like the ham radio, complete with "Over" to tell the other person that they can talk now) except it would be even MORE annoying because it would be a minimum 2 seconds before they could reply (Geosat ping times being what they are).
    • There are several methods for communications through amateur radio. The slow method would be via a message traffic system, the quicker would be phone patch.

      A large segment of hams participate in the National Traffic System (NTS), which transports messages from station to station, sort of like a telegram. When the message is routed to an area where it is a local phone call, the receiving ham would call the recipient and read off the message. Not overly fast, but it is free and usually works very well. If on
  • by smcavoy (114157) on Tuesday February 15, 2005 @05:16PM (#11682651)
    It seems like this would be something basic the government would provide to the people who are risking their lives EVERYDAY.
  • Over-the-sattelite latencies are pretty bad even in dedicated sattelite phones. Add the IP-level issues and it is just impossible.

    Instant messengers (Yahoo!, AIM, MSN, etc.) are free and, most likely, are much easier for your contacts in US to install too.

    Good luck!

    • I'm not in the military, just a consultant that travels a lot worldwide . . . Even I can appreciate the emotional difference between IM'ing and hearing the voice of the people you love.

      It's easy for me to empathize with the desires of these soldiers . . . they are away from home longer than I am, and they are risking their lives. I can completely understand their desire for something more than IM and cheaper than normal long distance rates for hearing the voices of their loved ones . . .

  • Half duplex with a 2 second wait in between, I just can't see any other way to do it with Sattelite ping times. I think you're better off with a Sattelite phone so that you don't have the additional bandwidth cosiderations of IP protocol (which with streaming applications is really bad- almost quadrupling the size of the packets).
  • Heads up (Score:5, Informative)

    by Eol1 (208982) on Tuesday February 15, 2005 @05:19PM (#11682702) Homepage Journal
    While possible offtopic would like to warning the poster though he mentions he is getting a commerical line.

    As a former theatre level Information Assurance Manager, VOIP works through the great DOD firewall in the sky (to include SWA). I know the current IAM and while he is a good guy, you never know when command is going to get in the mood to bust troopers for stupid shit (like non AKO IM). VIOP is against AR 25-2 and CENTCOM 25-260 .... watch your ass, with all going on your don't need a ART15.
    • Re:Heads up (Score:3, Informative)

      by ChiefArcher (1753)
      They are talking about getting their own net connection.. Not going through DISA SWA.

      BTW, I was the one locking down the firewalls in S. Iraq / Kuwait. :) I left there.. so i have no idea what state they are in now.

    • Re:Heads up (Score:2, Informative)

      by Anonymous Coward
      By way of clarification: Deployed soldiers are only supposed to communicate via approved secure communications channels, and breaking this rule can and does result in diciplinary action. Military channels (such as payphones on aircraft carriers, military satellite phones, etc.) are secured, recorded, and actively monitored. The US Govt strongly discourages military personel from going around these channels for obvious reasons.
    • So back in the mumblety-late-60s, a buddy of mine was working communications at Offutt AFB, home of the Looking Glass weapons-of-really-mass-destruction flying control center. The Looking Glass bird had a small PBX on board to connect users to each other and to the rdio uplinks from the ground. You can get to that PBX by dialing the right phone numbers on the base PBX. The military had a private worldwide phone system called AUTOVON that had interesting features like call priority and preemption.

      One d

    • That's gotta be the most acronyms I've ever seen in one paragraph. I'd forgotten what it's like to do business with DoD :)
  • by StateOfTheUnion (762194) on Tuesday February 15, 2005 @05:20PM (#11682708) Homepage
    I use vonage from Europe to call the US and find the quality great . . . however I have a land based DSL connection.

    Vonage says this [vonage.com] about satellite internet:

    Yes, our service generally works with DSL Satellite Internet connections or any Point-to-Point Protocol over Ethernet (PPPoE) device (i.e. your home router). DSL requires Point-to-Point Protocol over Ethernet (PPPoE) authentication "username & password" to access the Internet so you will have to configure your Vonage adapter or home router for this service. There may be some latency inherent on a satellite connection or line of sight issues that could affect audio quality when making calls through the Vonage service. Our calls require 90 kbps of consistent upload/download speed to make and receive calls through the Vonage network.

  • On Vonage's site, for best voice quality Vonage recommends 90 kbps. That's upstream traffic.

    so depending on how many people you want to be able to talk at a time, you should multiply that by the number of people and come up with your upstream traffic requirement.

    I'd also recommend you pad that number by 50 to 100% because other programs that try to upload at the same time don't often play nice with Vonage. The bandwidth is supposed to be dedicated while you are talking but other applications try to stea
  • by ChiefArcher (1753) on Tuesday February 15, 2005 @05:21PM (#11682729) Homepage Journal
    I used VoIP in Iraq/Kuwait when I was there.
    Worked great. As long as you only go through 1 sat hop, it really wasn't that bad. It's better than nothing. I used packet8 out there btw.

    Back in the US,
    ChiefArcher

  • Some Thoughts (Score:4, Informative)

    by spacefrog (313816) on Tuesday February 15, 2005 @05:24PM (#11682759)
    I would test-drive your VoIP provider of choice over the connection before you drop the bucks, if VoIP is a make-or-break.

    I've had both satellite Internet (Starband...yeeech) and Vonage (after I was able to get cable). While I love Vonage, I would not want to dream of that over satellite latency.

    On top of that, a 2-directional satellite system is unlikely to have the upstream bandwidth to make this smooth. Vonage has a "bandwidth saver" that you can enable, but that might be like pissing in the ocean.

    That being said, a high-speed, albeit high-latency connection is a very very good thing(tm) even without voice.

    Your bandwidth is still limited, so some traffic shaping and transparent http proxying might be in order.

    For the communications side of it, perhaps set up a (possibly private) IRC channel where your buddies and family can hang out. You could even setup a local IRC server on your gateway box and link it with an ircd in the states. Don't know how much bandwidth you would save, but it would be cool.

    My hats off to you and all of our fighting forces. Whether the war is just or not is an issue with the government, you guys go in harm's way every day.
  • by YrWrstNtmr (564987) on Tuesday February 15, 2005 @05:25PM (#11682771)
    For 2 things:
    1) Clearance to do this
    2) Assuming 1) is OK, recommendations on local connections.
  • If you don't mind the HUGE latency, I'm sure one of the many Linux fanatic can conjure up a neat vanilla box outfitted with six PCI-based audio cards and carry up to six conversation at once.

    Free phone calls may be well-received by most soilders who are desperate to hear the voice of their love ones (delayed or not).

    The core technology, that being said, is the Internet connection. You say you have it already.

    Just ask one of the many USA-based>/A> LUG groups for a donation of a box complete with si [linux.org]
  • Latency.... (Score:2, Informative)

    by Jas Tilak (859740)
    ITU-T recommendations for toll-quality voice are 150ms round-trip latency which you've got Buckley's chance of getting across a Sat link. That being said, if your expectations are that you are using a Satellite phone, then much higher figures might be quite acceptable. I second the vote for Skype. The iLBC codec it uses degrades very gracefully over low-quality links.
  • VoIP over Satellite (Score:5, Informative)

    by qi3ber (144534) on Tuesday February 15, 2005 @05:28PM (#11682814)
    I work for a VoIP company that sells wholesale termination to customers in various coutries around the globe. Many of our customers come from locations where a landline isn't an option, and use satellite to carry their VoIP to us. From their experience we can say that on average, you're going to be able to handle about 7 simultaneous calls per 128Kbits of upstream. The calls themselves only take up about 12Kbits (each direction) per call, but there will be other data you're likely to be contending with that will eat up some of your available bandwidth.

    As others have said, latency is going to be a problem, but from that part of the world, your likely already experience the joys of satellite latency in your "normal" calls. Again, our experience here is that as long as you can keep your latency below about 750ms you're going to have usable calls. A big factor here is the number of satellite hops your provider is send you through. A single hop will keep you under 750, while two hops will generally break the 1000ms barrier.

    Anyway, hope those numbers help you in your considerations, and take care.
    • The most popular voice compression algorithms these days use 8kbps for the voice codec itself, but that's a large number of small packets; vanilla IP headers typically bump that up to 23-36kbps per call. You can avoid this in a couple of ways, either by doing header compression which gets you into the 11-13kbps range, or by using voice native over layer 2 (frame or ATM) without the IP, or by packing voice bits from multiple calls into a single packet (arbitrarily low overhead if you've got lots of calls on
    • I'm currently using VOIP and a horrible connection with a satellite. The VOIP works fine. I live in Africa. I use dial up internet and can usually connect at 33.6. I then use a one-way satellite downlink for the return traffic.

      I'm using http://www.packet8.net/ [packet8.net] for my VOIP. Their tech support [packet8.net] says that the latency shouldn't be greater than 300ms for effective use. My latency is usually between 900ms and 950ms. As long as it's under 1000ms, the call quality and voice delay is fine if not better than using

  • QOS is not what you need to focus on.

    Latency in this application will kill your sound quality far more than a few dropped packets. Optimally you'll want to be under 300ms for things to be manageable.

    The other main thing to look for is a CODEC you can use with your chosen provider that uses as little bandwidth as possible and supports loss concealment. You need to worry about those two factors long before QOS becomes relevant to the equation.

  • One of the PCs on my home network hosts a Ventrilo http://ventrilo.com/ [ventrilo.com] server (very minor overhead.) My group of friends installed the small client software and connect to a password protect "chat" room.

    Push-to-talk and voice-activated modes are offered. The client software offers enough options to (possibly) intimidate new users, but once configured it is as easy as it gets.

    However, a previous post mentioned the use of AIM to communicate with troops overseas. Many IM clients are now integrating voice
  • I am not in Iraq, but I use a satellite based internet service called Starband ( http://www.starband.com/ [starband.com]) and I have a (claimed) 500/128kbit connection, but I usually get 50kbit/sec upstream. Using Vonage with a Motorola VT1000 VoIP terminal and the "Bandwith Saver" fuction turned down to 30kbits/sec I have no problem making and reciving one call at a time. I have the VT1000 in between the network and the satellite modem so that I don't kill my call when I download a webpage. The latency is about 1 sec,
  • Speed of Light (Score:3, Insightful)

    by bizitch (546406) on Tuesday February 15, 2005 @05:45PM (#11683023) Homepage
    In this case - the speed of light (speed of the electromagnetic spectrum) is just not fast enough for VOIP - no matter how much bandwidth or QOSing you want to do.

    Think of what you see when you're watching someone on the news "live" from somewhere via satelite. There is at least a full 1-2 second delay before he/she responds to a question. Thats the speed of light delay causing that, you've hit a brick wall of physics.

    You may still use VOIP - and the quality will not be bad - but dont expect any kind of normal telephone experience. You (and the people you talk to) could get used to a kind of walkie-talkie VOIP experience that may be the best.
  • Balad, Iraq (Score:2, Informative)

    by Ragnarr (555058)
    Recently home from the great sandbox! The way we did it was through our conractor friends. They had access to VOIP, I'm sorry I don't remember what brand however. I know they were relying on Satellite to transmit as well. Anyways, good luck over there! Oh, and join the AF, we have plenty of DSN lines.. :)
  • Skype (Score:2, Interesting)

    by gonzo67 (612392)
    A retired soldier (Col Dave Hughes)(http://www.odessaoffice.com/wireless/Himal ayas/Hughes.htm) who set up a wireless network in Nepal has used Skype to talk to the folks there from his home in Colorado, with little latency and good quality. The connection included a sat internet connection and several hops via wireless connection in Nepal.
  • There is a simple (but excellent quality) VOIP package called Speak Freely that's available for Linux and Windows (source is published too), and most importantly works nicely in simplex mode. I'd forget about telephone style full duplex over a sat link...this is more like a 2-way radio with a push-to-talk button.

    Speak Freely offers a variety of compression modes including some modes that'll squeeze your voice comms down to well under 14.4kbit. You can also enable solid crypto if you need some privacy. [

  • I've done it with up to two sat hops without much problem. For a geo-synch bird, expect 620-630ms latency roundtrip from one end of the connection to the other for each earth-sat-earth hop in the path.

    VoIP guidelines generally say 150ms is the latency limit, but in my experience, jitter is more important to overall call quality. A stable, low jitter connection with higher latency will have a higher MOS score (sound better) than a high jitter, low average latency connection.

    For reference, my config was usi

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