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From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Michael D
Schelin
Sent: Thursday, 12 May 2005 7:32 AM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: Re: [Asterisk-Users] Satellite Providers The delay in the air is minor.
Radio travels very fast through the air. Almost at the speed of light. It's the
electronics that are causing the delays. The less electronics touching
your signal the better. The up and down is very fast. But then you
have all the converts and the land line links to factor in. Microwave also
has delays such as the Motorola equipment which is only half duplex. This
will also incress the time. Max is right, check into some ground based
systems.
<sigh>
geostationary orbit is about 38,000 km above the equator, a
ping from a host in the us to another host in the us via a vsat link will travel
the following distance:
(2 x Distance from HostA to Uplink) + (4 x 38,000km) + (2 x
Distance from Satellite NOC to HostB)
Which could be if HostA is directly connected to
vsat...:
(2 x 10m) + (4 x 38,000km) + (2 x 1000km)
=
20m + 152,000km + 2000km =
20m + 154,000km =
~154,000,000m
Which should take about 500ms plus about 50ms for _ALL_ the
electronics in between.
So ping times should be expected in the 550-800ms range for
a good connection.
I use satellite (vsat) all the time and I am using SIP and
IAX2 with good sound but about 800ms delay, which is ok once you get used to
it.
Regards,
T
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