I hope someone can give me some advice on the following; I require broadband via satellite as I am moving into a street/town, where there is no broadband availability.
The broadbank internet access is needed for using the internet (mainly email sending & receiving) but also VOIP facilities to be reached with my current UK VOIP phone number and also be able to use VOIP calling facilities from different providers, using a normal phone for it, rather than the computer.
I am trying to find out whether it's possible to simply purchase the technical equipment and then use internet/phone/voip via satellite rather than going via a satellite internet company and paying monthly fees. Has anyone got experience with this?
I would also like to hear from anyone who has general (good or bad) experience with companies offering bi-directional satellite internet & phone/VOIP service.
Im with Roger very bad experience. VOIP doesnt not work very well with 2 way satellite systems, latency problems cause very bad reception over voip doesnt matter what your allowance is. Move to a different house with broadband available and telephone connection this is the best quality you will get with voip and then its hit and miss. Sorry to be so down check out my post on can anyone provide me with a good staellite connection in spain it tells you a bit more.
Low cost systems, designed for intermittent bursty web browsing traffic, can only provide for continuous VoIP transmission if the software and protocols are such as to prioritise VoIP packets over all other traffic. VoIP packets cannot be delayed and queued up like emails and web page downloads, otherwise the audio voice sound waveform will suffer gaps and jitter.
In my experience VoIP works fine if you use dedicated continuous satellite capacity in both directions. Cost is around $50 per month per 10kbit/s. G729A VoIP voice coding is typically 8 kbit/s but with TCP-IP encapsulation overheads the total can be in the range 14 - 24kbit/s. So 25kbit/s each way (total 50k @ $250 per month) would be good for one phone line. Plus terrestrial costs and any call terminating charges of course...
« Last Edit: Oct 4th, 2006 at 7:39pm by Eric Johnston »
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pgannon
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Reply #6 - Oct 4th, 2006 at 6:03pm
Computer3 you said:
I am trying to find out whether it's possible to simply purchase the technical equipment and then use internet/phone/voip via satellite rather than going via a satellite internet company and paying monthly fees.
PAT: No, you cannot simply buy the equipment and gain access to a satellite connection without paying monthly fees. You may be able to pay annually in advance, for example, but satellite bandwidth is a commodity paid for monthly like any utility service. You do not necessarily have to have a satellite link that goes to the Internet, you can set it up between any two sites that can be seen from the same satellite; but VoIP by its very nature is designed to go over the Internet to a VoIP termination provider.
You said: I would also like to hear from anyone who has general (good or bad) experience with companies offering bi-directional satellite internet & phone/VOIP service.
PAT: As you can see from the responses, VoIP does not work on many satellite services. However, as Eric indicated, there is a very wide range of VSAT services available. Residential and small office/home office class services generally will not provide good support (or often any support) for VoIP service. However, business class voice quality is very possible and is used by thousands of people every day. You need an enterprise class system that provides the following features:
CIR - committed information rate - this is dedicated bandwidth. Using VoIP is like turning on a faucet. A steady, continuous flow of bandwidth is required and must be guaranteed or your VoIP won't work, or will work very poorly. A critical component for CIR is to ensure that the network operator does not oversubscribe CIR, because if they do, it is no longer "committed" and can not be counted on to be there when needed to deliver good voice quality.
QoS - quality of service. You need a system that will prioritize your VoIP so that the voice packets are handled before other non-critical traffic such as browsing or email packets.
Jitter control - it's not latency that kills voice, it's inconsistent latency. Anyone can easily learn to live with reasonable satellite latency (500 - 700ms), but inconsistent latency will kill voice quality. You need a system that provides the technology to minimize inconsistent latency. Most systems deliver VoIP packets in "clumps" which leads to jitter, rather than spacing them out. VoIP packets need to be evenly and smoothly spaced and delivered to ensure minimum jitter. One component of this is....
SAR - segment assembly/reassembly. Even with Qos, a large FTP packet for example, can hold up the smaller VoIP packets, creating jitter. SAR breaks the big packets up into smaller chunks, evenly spaces small VoIP packets between them, and then reassembles the large packet at the other end of the satellite connection.
cRTP - compressed real time protocol, is not a required feature for good VoIP, but it significantly reduces the amount of TCP overhead and thus the amount of CIR required for each VoIP line. Using cRTP a G.723 codec will require about 11 Kbps per VoIP line and a G.729 codec will require about 14 Kbps per VoIP line.
Most "shared" satellite services are unable to provide these features. iDirect-enabled services delivered by a knowledgeable and experienced network operator are able to do so by providing a mix of shared bandwidth for data use and CIR for VoIP or other critical applications. Contact me me with your location (UK?) offline and I'll provide you with a quote for iDirect-enabled services.
Altternatively 100% dedicated services called SCPC (single channel per carrier) will deliver good VoIP providing you use external equipment to provide the QoS and other features necessary for good quality. For a couple PCs and a single VoIP line, this is probably not going to be cost effective.
