Hi All, I am investigating the deployment of VoIP/* in Eastern European areas where there is no PSTN infrastructure. As you can understand DSL/Cable connections are a dream. The only option is satellite. Does anyone know of any satellite providers that have low enough/acceptable delays for VoIP? Thanks, Yiannis.
We looked at this earlier this year and, after evaluating several companies, could not get it to work well enough. The problem didn't seem to be latency, but rather lost packets in the upstream direction. Most of the time, we couldn't even get the phone to register, but even when we could, there was such a large amount of breakup (in the up direction) that it was nearly unusable. We tried low-end, consumer type services and they didn't work at all. Even the high-end services that claim to offer guaranteed bandwidth apparently do not live up to their claims. We tried running G.729, which should only need about 32-40k over a link that claimed to guarantee 64k, and the best we got was broken sound. Bruce Komito High Sierra Networks, Inc. www.servers-r-us.com (775) 236-5815 On Wed, 11 May 2005, Yiannis Costopoulos wrote:> Hi All, > > I am investigating the deployment of VoIP/* in Eastern European areas where > there is no PSTN infrastructure. As you can understand DSL/Cable connections > are a dream. The only option is satellite. > > Does anyone know of any satellite providers that have low enough/acceptable > delays for VoIP? > > Thanks, > Yiannis. > > _______________________________________________ > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > This message has been categorized as "Legitimate" by Bayesian Analyzer. > If you do not agree, please click on the link below to train the Analyzer. > http://nospam.wpti.net/bt/a.aspx?M=C:%5Csmtpmail%5CBayesTraining%5C2005-05-11%5Cc819e577de1140fbaa62d0a53c83de86&C=2 > > -- > ----------------------------------------------------------------------- > This message has been inspected by DynaComm i:mail > ----------------------------------------------------------------------- > >
> Hi All, > > I am investigating the deployment of VoIP/* in Eastern European areas > where > there is no PSTN infrastructure. As you can understand DSL/Cable > connections > are a dream. The only option is satellite. > > Does anyone know of any satellite providers that have low > enough/acceptable > delays for VoIP? > > Thanks, > Yiannis. > >You might want to have a look at Aramiska - They already have skype listed on their pages as an option.
Satellite delays are always bad. It is more a delay because of the time it takes a signal to travel to the satellite and back to a receiving station. You might want to check into ground station to station microwave communications stations. The best is to have a tap to a phone company that may have cell towers in the area. Cheers, Max> -------- Original Message -------- > Subject: [Asterisk-Users] Satellite Providers > From: "Yiannis Costopoulos" <lists@w2ns.com> > Date: Wed, May 11, 2005 12:23 pm > To: <asterisk-users@lists.digium.com> > > Hi All, > > I am investigating the deployment of VoIP/* in Eastern European areas where > there is no PSTN infrastructure. As you can understand DSL/Cable connections > are a dream. The only option is satellite. > > Does anyone know of any satellite providers that have low enough/acceptable > delays for VoIP? > > Thanks, > Yiannis. > > _______________________________________________ > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users
I have a number of VSAT links from Africa to the US. They all run 530ms, you can not defy the laws of physics. Across 4 different birds the latency is virtually identical. John Dunham -----Original Message----- From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com]On Behalf Of bryan hepworth Sent: Wednesday, May 11, 2005 1:30 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Satellite Providers> Hi All, > > I am investigating the deployment of VoIP/* in Eastern European areas > where > there is no PSTN infrastructure. As you can understand DSL/Cable > connections > are a dream. The only option is satellite. > > Does anyone know of any satellite providers that have low > enough/acceptable > delays for VoIP? > > Thanks, > Yiannis. > >You might want to have a look at Aramiska - They already have skype listed on their pages as an option. _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Well there are several problems in your description of Satellite services. For one you are grouping several differing technilogies together as one. What it seemed like you were testing was a shared bandwidth solution typically used by providers to reduce cost. It isn't uncommon to experience sever delays and packet loss on these types of systems. Alot of these shared providers "claim" 64k cir then oversubscribe over that. Lies, yes, theift yes, and they get away with it... What you would want to ask for is a SCPC (Single Carrier Per Channel) circuit and you should have much better results, cost? a lot more than these shared solutions. You may want to look into the maritime providers/teleports in the area for this type of service. Delay for a decent circuit should not be over 600 ms and it should be steady. Proof is in the pudding, in a SCPC circuit with a v.35 interface you can run an extended BERT test on it without error. and that's Sync data... I speak confidently on this as we are a provider of VSAT services in the oilfield industry. We are bombarded with these "low cost" competition and have to defend ourselves daily. Alot of providers sell crap at a decent price. We don't and won't. It hurts our market penetration but we tend to keep customers for a good long time. I can answer a lot of questions on this subject if anyone needs. It's a lot like point to point microwave, they experienced their "bandwidth sharing" days and they quickly died on the vine. The driving force behind shared solutions is that satellite bandwidth is expensive. Chad C. Wicker Systems Engineer Petrocom>>> brucek@bagel.com 5/11/2005 1:06:52 PM >>>We looked at this earlier this year and, after evaluating several companies, could not get it to work well enough. The problem didn't seem to be latency, but rather lost packets in the upstream direction. Most of the time, we couldn't even get the phone to register, but even when we could, there was such a large amount of breakup (in the up direction) that it was nearly unusable. We tried low-end, consumer type services and they didn't work at all. Even the high-end services that claim to offer guaranteed bandwidth apparently do not live up to their claims. We tried running G.729, which should only need about 32-40k over a link that claimed to guarantee 64k, and the best we got was broken sound. Bruce Komito High Sierra Networks, Inc. www.servers-r-us.com (775) 236-5815 On Wed, 11 May 2005, Yiannis Costopoulos wrote:> Hi All, > > I am investigating the deployment of VoIP/* in Eastern Europeanareas where> there is no PSTN infrastructure. As you can understand DSL/Cableconnections> are a dream. The only option is satellite. > > Does anyone know of any satellite providers that have lowenough/acceptable> delays for VoIP? > > Thanks, > Yiannis. > > _______________________________________________ > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > > This message has been categorized as "Legitimate" by BayesianAnalyzer.> If you do not agree, please click on the link below to train theAnalyzer.>http://nospam.wpti.net/bt/a.aspx?M=C:%5Csmtpmail%5CBayesTraining%5C2005-05-11%5Cc819e577de1140fbaa62d0a53c83de86&C=2> > -- >-----------------------------------------------------------------------> This message has been inspected by DynaComm i:mail >-----------------------------------------------------------------------> >_______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
The altitude of a geostationary satellite is about 37500 km for a round trip distance of aboyt 75000 km. Light travels at 300,000 km/second, so you have a latency of about 250 ms per hop. That is just for the transit time to and from the bird. Since you have a two way conversation, a caller asking a question would have to wait a minimum of 500 ms for a reply. This does not include any signal processing that might take place. In other words, you will still have to account for the "normal" voip latency. A satellite path might have several hops, each adding its own 500 ms delay. With a geostationary satellite, you really can't have anything approaching a full duplex/real time telephone conversation. The conversations you have would more closely resemble simplex two-way radio conversation. That being said, if that's all you have, useful communications can be had using this mode. The International space station, for instance. uses several TDRS satellites to communicate with Houston. The big thing is training the users. Bill On 5/11/05, Yiannis Costopoulos <lists@w2ns.com> wrote:> Hi All, > > I am investigating the deployment of VoIP/* in Eastern European areas where > there is no PSTN infrastructure. As you can understand DSL/Cable connections > are a dream. The only option is satellite. > > Does anyone know of any satellite providers that have low enough/acceptable > delays for VoIP? > > Thanks, > Yiannis. > > _______________________________________________ > Asterisk-Users mailing list > Asterisk-Users@lists.digium.com > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users >
Aparantly Light Travels Faster in your world than it does in mine. As an example, A new Satellite that was launched Just a few days ago (April 26) is in orbit at 22,300 MILES above earth. Assuming that both ends of the transmission are directly below the Satellite (Which they will not normally be, adding even a few more percentage points of distance to this calculation); the total round trip distance is 44,600 MILES. Again, Assuming a perfect world where humans didn't need to breathe or be protected from UV and other cosmic rays which would allow us the opportunity of moving light at 186,000 miles per second, that means that the time IN ONE DIRECTION to get data from point a to point b with absolutely NO 'electronic' delays would be 44,600 Miles / 186,000 Miles/Sec = 240ms. PING Time would be double that, or about 480ms Seems that John Dunham only has 50ms (OR LESS) of 'electronic' delay in his VSAT Links (And again, that assumes that both point a and point b are DIRECLTY under the satellite, which I doubt they are), and that sounds like a relatively small percentage of the total delay when compared to 480 ms of 'through the air' time. Best Regards, Ben Bawkon>The delay in the air is minor. Radio travels very fast through the air. Almost at the speed of light. It's the electronics that are causing the delays. The less electronics touching your signal the better. The up and down is very fast. But then you have all the converts and the land line links to factor in. Microwave >also has delays such as the Motorola equipment which is only half duplex. This will also incress the time. Max is right, check into some ground based systems.>Max W Blackmer Jr wrote:>>Satellite delays are always bad. It is more a delay because of the time >>it takes a signal to travel to the satellite and back to a receiving >>station. You might want to check into ground station to station >>microwave communications stations. The best is to have a tap to a phone >>company that may have cell towers in the area.>>Cheers,>>MaxThis message was checked by MailScan for WorkgroupMail. www.govarion.com