Author Topic: Satellite modem to router: DMZ / port forwarding  (Read 591 times)


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Satellite modem to router: DMZ / port forwarding
« on: 2018-12-05, 17:46:09 »
Hi, I have gotten our FT-857 working well on a LAN. I have set a DMZ on the Radio router for its IP address. But this router connects to a Xplornet Satellite modem that I think has a firewall as well, so no luck connecting outside the LAN so far. I don't know much about separate modems to routers. I am waiting for account info to call the Satellite company.

In the mean time, has anyone had success with this kind of setup?

Thanks in advance,
Chris VA3ECO


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Re: Satellite modem to router: DMZ / port forwarding
« Reply #1 on: 2018-12-05, 19:19:30 »

You have two problems, neither of which is solvable:

1) The second modem/router would have a different external IP address as the first router. Since RemoteRig
requires the router connected to the radio RRC to be the one addressable over the internet, your RRC
will never be reachable over the internet. This is not a firewall problem, but is caused by the issue known
as "double NAT". The only way around this would be using a VPN. There has been some discussion on this
forum if you search "double NAT".

2) A satellite connection will NOT work with RemoteRig, the latency is too high to make it effective. You may be
able to do some limited SSB work if you can work around the latency, but any other mode would be impossible.
This has also been discussed on this forum, but to sum up, a geosynchronous orbit is 40,000 km, the speed of
light is 300,000 km/s. The signal must travel back and forth twice for total of 160,000 km, not including ground
travel and network latency. The travel time alone requires therefore about 530 ms of latency, plus the other factors
would add another 200+ ms, or a minimum of 700 ms latency (about 3/4 of a second). That is the reason that
worldwide telecommunications has moved off of satellites.

Mitch DJ0QN / K7DX


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Re: Satellite modem to router: DMZ / port forwarding
« Reply #2 on: 2018-12-05, 22:29:28 »
Hi Mitch,
Thank you for this quick response.

It is actually my friends remote rig and his son's satellite internet location.
I did not know it was satellite until I saw the modem sitting beside the router on the shelf, but suspected it when I did a speed test on my laptop (SpeedOf.Me, very nice speed tester) and noticed a large latency, like you mention.

So my friend will consider his options, maybe relocate to a local isp or something.
Thanks again.
-Chris VA3ECO