David Gibbons wrote: > <snip> > ...routing via satellite adds about a quarter second of latency to the path. > Is that too much? > </snip> > > Eric, > > I believe that you are mistaken. Routing via satellite adds about a quarter > second of latency PER TRIP from earth to orbit. This is simply due to the > distance a satellite is from the ground and the speed of light (interference > not withstanding). > > Traceroutes and pings to satellite providers can be misleading because they > cache some content on the birds in order to decrease latency. As I recall > they even intercept some pings to accomplish the same. > > A *real* round trip for a VOIP call and/or non-interfered TCP connection > would look like this: > > 1. Your device up to the bird (~250ms) > 2. The bird back to the ground (~250ms) > 3. The ground station out to the internet (~Nms) > 4. The internet back to the ground station (~Nms) > 5. The ground station back to the bird (~250ms) > 6. The bird back to your device (~250ms) > > As you can see, even the one way udp stream will take approximately 500ms > beyond any latency introduced by things such as your wireless network and the > internet. VOIP over satellite, as Josh indicated, will be painful. You'll be > talking all over one another due to the delay assuming that the stream can > even be sustained with that much latency. > > -Dave > > _______________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > > asterisk-users mailing list > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > Of course, that's assuming your satellite is in geosynchronous orbit. If its in LEO, then its much better.
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