SatSig topic:

Skype over Satellite Broadband (Tooway?)?

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Jul 8^th, 2008 at 5:31pm

Has anyone successfully used Skype over satellite?

I thought it would not be possible because of the latency issues but I have seen in my searches companies offering VOIP over Sat.

So as its a similar technology to VOIP would it be possible?

Is standard SIP possible over VOIP?

If any other the answers above are a yes...would it be possible using Tooway?

Or if know one has tried using Skype over Tooway what package are you using and how much does it cost each month and how much is it to install.

I'm looking for a connection in Italy

Jul 9^th, 2008 at 6:38pm

Hello, We install Tooway all over Europe, VOIP is not a problem technically, it works using the right settings, but with Tooway upload speeds nowhere near the expected 384kbps its cureently not good for Skype or VOIP use. its just that no ISP or Tooway themselves will say its supported. We hope the speeds wil improve.
We can supply just the kit for you, or fully installed, whichever you prefer. Our web site is https://notesconsultants.bttradespace.com/TSProductGroups/AllItems.aspx

Sep 30^th, 2008 at 8:38pm

Hi,

I have used Skype on Tooway and although the upload speeds are not great the connection was not bad.

Sep 30^th, 2008 at 10:00pm

I've successfully operated VoIP over dedicated satellite links, but had problems when operating with shared TDMA uplinks. The minimum bit rates needed are about 10.8kbit/s for VoIP and 14.5 kbit/s for Skype, but the bit rates required can be very much higher if you have not configured both ends for minimum bit rates and packet header compression. This is very difficult until you understand the equipment at the VSAT site and at the hub - it took me several months till I learned how get it right - and this only for the particular VoIP phones and modem and hub hardware I was using.

Read more: https://www.csl.uiuc.edu/mcc/pdf/unit27.pdf

In a system like Tooway the uplink is 384 kbit/s (Ka band) or 156k (Ku band) but you need to understand that this 384k or 156k bit/s is in the form of bursts from many uplink sites, with gaps. Typically each site sends a short burst when the mouse is clicked, with then a delay waiting for the correct moment to transmit so that the burst does not overlap with anyone else's burst when it arrives at the satellite. If you want to upload a large file then your modem negiotiates with the hub NMS to assign you a block stream of contiguous burst time slots and your upload file goes fast, as one large block of data. You send all your bursts at 384 or 156 kbit/s. Most bursts are small; the few long planned bursts are much longer. For 99% of the time you are NOT transmitting.

When you attempt VoIP or Skype you want to send a stream of bursts with steadily timed spacing to make for smooth speech. This does not fit well with the mouse clicks and file uploads from other people using the same uplink of 384 or 156 kbit/s. To solve this, some VSAT systems incorporate QoS systems which will prioritise VoIP packets and make it work well. Even with this you still need to configure your VoIP phones and hub VoIP equipment with correct codecs and samples per packet etc.

Latency (fixed delay due to distance) was not a problem for me with simplex type converations, but it can be embarrasing in the case of sensitive negotiation type conversations where the silences and their length and brief grunts and hint type verbal noises carry meaning.

Best regards, Eric.