Comment VSAT and VoIP for the soldiers (Score 1) 362
I'm the CTO and of the BusinessCom Internet via Satellite (www.bcsatellite.net) which is widely deploying VSAT and VoIP links worldwide and particulary for US Soldiers in Iraq. We have more than 1500 US soldiers currently using our services in Iraq and Afghanistan to communicate back with their dear ones in US and everybody seem to be pretty happy. I can't say we offer the cheapest service in the world, more like we are insisting on the optimal balance of price and performance. First of all, to assure the adequate quality of the VoIP phone call, the customer should understand that there's a variety of VSAT technologies available on the market.
Below, I would just paste the standard text of my reply to compare several VSAT
technologies which are present on the market. In a nutshell - this is
how the broadband satellite industry looks today:
1. Hughes and Gilat are the largest players with DirecWay, PES, Starband,
Spacenet, and other services. The thing to keep in mind about these guys is
that their solutions were designed for credit card approvals and lottery
ticket sales. They were designed for transaction-oriented services -
occasional short transmissions, and they do an excellent job of this. What
you see is an attempt to shoe-horn their technology into the IP WAN business
when it was never designed for it - and it does a poor to mediocre job of
this. They have long latency (3 second transaction time was part of the
original design criteria), horrible jitter which kills VoIP or requires
large jitter buffers that store the voice for an extra second or two to
remove the jitter, and their data service is inefficient and sluggish.
This class of stations is priced approximately 2000 Euro for the standard
system.
2. DVB/RCS and similar systems from companies like Viasat Linkstar, Shiron,
Tachyon, Vipersat and others. These systems are an improvement over the
Hughes/Gilat stuff, but they have done little to improve the uplink
technology. Jitter continues to be a big problem for these products. They do
not support voice well; they take up to 10 seconds to allocate CIR bandwidth
(when they support it), pings are longer and more inconsistent, etc. The
hardware prices are usually pretty good, but the service prices tend to be
higher because of the inefficiency. Because of this many of the network
operators who sell these services tend to oversubscribe their networks too
much, which creates poor performance. The business model is designed so that
you can only make money with large oversubscribed networks, rather than
smaller customized networks like iDirect. However, DVB/RCS is still the best
system on the market for home and small office/Internet cafe access where
VoIP/VTC is not required. DVB/RCS class of stations is priced similiarly to
the traditional TDMA systems, approximately 2000 Euro for the standard system.
3. DVB/SCPC uses shared bandwidth on the download and SCPC on the upload.
This isn't a bad solution, but it is expensive, because the uplink bandwidth
is completely dedicated and is therefore very expensive. Adding to the cost
is the fact that a small amount of guard band is required between each SCPC
carrier and this wasted capacity has to be built into the cost. This
solution generally requires a mishmash of equipment. DVB receivers plus an
SCPC modem, with Cisco router, Mentat TCP Acceleration, and if you want any
QoS you have to add a Sitara or Packeteer or Allot box. The combined cost of
all these devices, and the expensive nature of the SCPC uplink make this a
costly solution with many potential points of failure and finger-pointing.
DVB/SCPC stations price is varying, depending on the particular configuration
of antenna and BUC. Usually it is within 9000-15000 Euro range for the
mid-level station suitable for up to 1 mbit/s uplink.
4. iDirect - This is the first system that was designed from the ground up
to support IP in a WAN environment. The real differentiator is that they use
router technology, rather than modem technology. While some of the other
Hughes, Gilat, DVB/RCS, etc. guys will have some rudimentary routing
capability on their VSAT terminals, the fact is that they are based on modem
technology. They don't have the concept of router queues, so the only way
they know to ask for more bandwidth is when they've already started to drop
packets on the floor because their buffers have overflowed. This is highly
inefficient. The iDirect solution uses router technology, and let's face it,
when you think of IP and the Internet, you think of Cisco routers. You have
to have router technology to offer good service for IP in a WAN environment.
I could go into all the other features and functions that iDirect provides
that the other guys don't, but most of this is spelled out pretty well on my
web site. The real test is the user perception, and users love the iDirect
technology for it's crisp, snappy response and toll-quality VoIP support.
iDirect station price is approximately 8000 Euro.
5. SCPC/SCPC - this is 100% dedicated bandwidth in both directions, and if
you have an application that is almost 100% voice and you have 20, 30, 50 or
more voice lines, then this is the way to go. It's quite expensive because
it's completely dedicated, unshared bandwidth, but sometimes that's what's
needed. In a data application or mixed voice/data networks, a shared
bandwidth solution is more efficient and costs much less. It's like the
difference between Frame Relay and a dedicated private T-1 line (not an
Internet T-1 which is oversubscribed and shared - a private T-1 between two
points, with no one sharing service but those two locations). You can think
of iDirect as Frame Relay and you can think of SCPC as a dedicated T-1 line.
SCPC stations are priced in the way DVB/SCPC systems do, approximately
9000-15000 Euro per station suitable for up to 1 mbit/s uplink.
We have combined a VSAT Technology Comparison Chart which is available for all who contacts us to understand what goes where in the VSAT area.
Also,
Voice is a steady stream of data. When you pick up the phone and make a call
you are sending a continuous stream of traffic until you hang up. If that
bandwidth is not protected, then someone else downloading a web page, or
making a file transfer or sending an email with a large attachment, will
step all over the voice causing noise, distortion, and even disconnects. We
require CIR or dedicated bandwidth for voice to protect it and make sure it
retains toll quality for the entire conversation. However once the call is
made and CIR is assigned no one else can share that bandwidth until the call
is finished.
There are two popular methods for transporting voice. A normal voice call on
the public telephone network takes 64 Kbps per call. When you turn it into
VoIP, you add IP overhead and it takes about 80 Kbps per call. This is using
the G.711 standard that basically has no compression. G.723 and G.729 codecs
(COmpression/DECompression) compress the voice so that it requires less
bandwidth. The iDirect solution that we market further compresses the voice
stream with something called cRTP header compression to remove some of the
IP overhead. A G.723 call takes about 11 Kbps per call and a G.729 call
takes about 14 Kbps per call. (This is a lot better than 80 Kbps per
call!!!).
To deliver a VoIP service you have to make arrangements with a VoIP
termination provider. There are many of them out there with all sorts of
business and billing plans, just do a google search on 'VoIP termination.'
Some that you may want to look at include:
http://www.ipcb.net/sales/market.php3
http://ww w.go2call.com/
http://www.callback4u.com/phone-se rvice/index.htm
http://www.pingtone.com/
http:// www.aventuranetworks.us/
http://www.kayote.com/
http://www.internetvoip.com/
This is far from a complete list. A good site to learn about VoIP is:
http://www.voip-calculator.com/support.html Usually VoIP termination
companies will support both standards and you can use whichever one you
want. G.729 will deliver a little better voice quality, but G.723 is almost
as good and it uses less bandwidth.
I hope this was of interest to you.
Below, I would just paste the standard text of my reply to compare several VSAT
technologies which are present on the market. In a nutshell - this is
how the broadband satellite industry looks today:
1. Hughes and Gilat are the largest players with DirecWay, PES, Starband,
Spacenet, and other services. The thing to keep in mind about these guys is
that their solutions were designed for credit card approvals and lottery
ticket sales. They were designed for transaction-oriented services -
occasional short transmissions, and they do an excellent job of this. What
you see is an attempt to shoe-horn their technology into the IP WAN business
when it was never designed for it - and it does a poor to mediocre job of
this. They have long latency (3 second transaction time was part of the
original design criteria), horrible jitter which kills VoIP or requires
large jitter buffers that store the voice for an extra second or two to
remove the jitter, and their data service is inefficient and sluggish.
This class of stations is priced approximately 2000 Euro for the standard
system.
2. DVB/RCS and similar systems from companies like Viasat Linkstar, Shiron,
Tachyon, Vipersat and others. These systems are an improvement over the
Hughes/Gilat stuff, but they have done little to improve the uplink
technology. Jitter continues to be a big problem for these products. They do
not support voice well; they take up to 10 seconds to allocate CIR bandwidth
(when they support it), pings are longer and more inconsistent, etc. The
hardware prices are usually pretty good, but the service prices tend to be
higher because of the inefficiency. Because of this many of the network
operators who sell these services tend to oversubscribe their networks too
much, which creates poor performance. The business model is designed so that
you can only make money with large oversubscribed networks, rather than
smaller customized networks like iDirect. However, DVB/RCS is still the best
system on the market for home and small office/Internet cafe access where
VoIP/VTC is not required. DVB/RCS class of stations is priced similiarly to
the traditional TDMA systems, approximately 2000 Euro for the standard system.
3. DVB/SCPC uses shared bandwidth on the download and SCPC on the upload.
This isn't a bad solution, but it is expensive, because the uplink bandwidth
is completely dedicated and is therefore very expensive. Adding to the cost
is the fact that a small amount of guard band is required between each SCPC
carrier and this wasted capacity has to be built into the cost. This
solution generally requires a mishmash of equipment. DVB receivers plus an
SCPC modem, with Cisco router, Mentat TCP Acceleration, and if you want any
QoS you have to add a Sitara or Packeteer or Allot box. The combined cost of
all these devices, and the expensive nature of the SCPC uplink make this a
costly solution with many potential points of failure and finger-pointing.
DVB/SCPC stations price is varying, depending on the particular configuration
of antenna and BUC. Usually it is within 9000-15000 Euro range for the
mid-level station suitable for up to 1 mbit/s uplink.
4. iDirect - This is the first system that was designed from the ground up
to support IP in a WAN environment. The real differentiator is that they use
router technology, rather than modem technology. While some of the other
Hughes, Gilat, DVB/RCS, etc. guys will have some rudimentary routing
capability on their VSAT terminals, the fact is that they are based on modem
technology. They don't have the concept of router queues, so the only way
they know to ask for more bandwidth is when they've already started to drop
packets on the floor because their buffers have overflowed. This is highly
inefficient. The iDirect solution uses router technology, and let's face it,
when you think of IP and the Internet, you think of Cisco routers. You have
to have router technology to offer good service for IP in a WAN environment.
I could go into all the other features and functions that iDirect provides
that the other guys don't, but most of this is spelled out pretty well on my
web site. The real test is the user perception, and users love the iDirect
technology for it's crisp, snappy response and toll-quality VoIP support.
iDirect station price is approximately 8000 Euro.
5. SCPC/SCPC - this is 100% dedicated bandwidth in both directions, and if
you have an application that is almost 100% voice and you have 20, 30, 50 or
more voice lines, then this is the way to go. It's quite expensive because
it's completely dedicated, unshared bandwidth, but sometimes that's what's
needed. In a data application or mixed voice/data networks, a shared
bandwidth solution is more efficient and costs much less. It's like the
difference between Frame Relay and a dedicated private T-1 line (not an
Internet T-1 which is oversubscribed and shared - a private T-1 between two
points, with no one sharing service but those two locations). You can think
of iDirect as Frame Relay and you can think of SCPC as a dedicated T-1 line.
SCPC stations are priced in the way DVB/SCPC systems do, approximately
9000-15000 Euro per station suitable for up to 1 mbit/s uplink.
We have combined a VSAT Technology Comparison Chart which is available for all who contacts us to understand what goes where in the VSAT area.
Also,
Voice is a steady stream of data. When you pick up the phone and make a call
you are sending a continuous stream of traffic until you hang up. If that
bandwidth is not protected, then someone else downloading a web page, or
making a file transfer or sending an email with a large attachment, will
step all over the voice causing noise, distortion, and even disconnects. We
require CIR or dedicated bandwidth for voice to protect it and make sure it
retains toll quality for the entire conversation. However once the call is
made and CIR is assigned no one else can share that bandwidth until the call
is finished.
There are two popular methods for transporting voice. A normal voice call on
the public telephone network takes 64 Kbps per call. When you turn it into
VoIP, you add IP overhead and it takes about 80 Kbps per call. This is using
the G.711 standard that basically has no compression. G.723 and G.729 codecs
(COmpression/DECompression) compress the voice so that it requires less
bandwidth. The iDirect solution that we market further compresses the voice
stream with something called cRTP header compression to remove some of the
IP overhead. A G.723 call takes about 11 Kbps per call and a G.729 call
takes about 14 Kbps per call. (This is a lot better than 80 Kbps per
call!!!).
To deliver a VoIP service you have to make arrangements with a VoIP
termination provider. There are many of them out there with all sorts of
business and billing plans, just do a google search on 'VoIP termination.'
Some that you may want to look at include:
http://www.ipcb.net/sales/market.php3
http://w
http://www.callback4u.com/phone-s
http://www.pingtone.com/
http:/
http://www.kayote.com/
This is far from a complete list. A good site to learn about VoIP is:
http://www.voip-calculator.com/support.html Usually VoIP termination
companies will support both standards and you can use whichever one you
want. G.729 will deliver a little better voice quality, but G.723 is almost
as good and it uses less bandwidth.
I hope this was of interest to you.
