Satellite Internet Forum

[outofstepper]

Greets all. Great resource here.  I'm a new subscriber to satellite internet service. I got my kit last week and have been up and running ever since. Was hoping to get a few pointers from those of you that have had the service for a bit.

Have to say installation was pretty straight-forward. I'm located in central Italy -- after calling tech support about polarization angle (I was supposed to *start* at 90 degrees!) -- it was pretty smooth. Used a cheap (less than 10 euro) satellite finder that I found at my local electronics shop. Looks to be exactly the same one in the installation PDF, judging by the photo. Couldn't get the sensitivity down without losing the signal altogether, but here I am.

At any rate, a few questions, somewhat in order of importance:

1. I assume that the accuracy of my installation effects performance -- correct? Just because I have a signal and I can run a decent speed test, I may not be seeing the whole picture? Any suggestions (equipment?) for getting the best possible installation? I'm hoping the answer is cheap (i.e. not a spectrum analyzer)

2. I do most of my work via VPN into a home office in the U.S. -- I notice that I have the most trouble uploading. That is, speed test says I have decent upload speed.. 200-300 kbps.. but I lose my connection (to the VPN) 4 out of 5 times on large file uploads. Any insight?

3. I do alot of Skype. Now I know satellite isn't suited, but its the only I option I have where I live. Round trip times have been up to 1.5 seconds but the connection seems to stay live and, well, considering my options, can't complain. I'm wondering if there is anyway to make this better? not roundtrip, but performance. Can I open any of the ports skype would like to see open? As far as I can tell there is no config options for my tooway router.

Thanks all. Tony

[AlexCidem]

1. Your service provider can access graphs showing your uplink and downlink signal levels over last month, last week etc and can determine if your signals are good enough, and by implication if your pointing is acceptable. Your site can be compared with others nearby. Example Twoway signal graphs (from el Molino Europe satellite):

Rx/Tx Signal Graph

Rx-Tx-Power.png (112.4 KiB) Viewed 663 times

S/N Ratio

S-N-Ratio.png (103.74 KiB) Viewed 665 times

Ask if they think you need to do anything. With an inexpensive signal meter is is possible to achieve excellent results, if you interpret the scale readings with skill. I would suggest degrading the signal either side to precisely equal degraded qualities and then setting the dish mechanically to half way between, both sideways and up and down. The polarisation is best set by calculation, starting from the nominal starting position.

I don't think you will see any benefit in speeds from correct dish pointing, during clear sky conditions, unless you are severely mispointed. The Ka band frequencies used by Tooway suffer attenuation from rain but the system has special link margin countermeasures which assure that the service survives light and moderate rain. During rain your uplink power will increase and the forward error correcting code rate may change. In the downlink to you, the modulation method and coding may also alter to assure continuing service.

Poor dish pointing is likely to show up with the symptom "outages during light rain", due to lack of adequate clear sky link margins.

2. VPN involves all your packets having special outer headers added to route them to your private company LAN. The content of the packets comprises an inner private destination address and your text etc. All the content may be encrypted. Encryption prevents the satellite modem and Skylogic hub from applying any acceleration processes so your VPN traffic does not really fit well into the satellite link. I don't know why your VPN line fails - as a guess it may be due to excessively long packets which have to be split up en-route. I suggest you talk to your company IP staff and ask if your VPN connection can be made suitable for a satellite link at your end.

3. I'm suprised that Skype works at all but there have been a few reports, like yours, of people getting some kind of service. I believe that Skype has some automatic adaption process - whatever, it is important to use the lowest speech coding rate and pack several speech samples per packet to minimise stress on the satellite link. The lowest tariffs on Tooway have traffic limits which you may meet rather quickly with streaming data flows like Skype and large file transfers. The table below shows typical useage quotas:

Tooway Usage Quotas in MB

Tooway-usage-quotas.png (22.39 KiB) Viewed 658 times

Your service reseller will tell you your specific limits.