Satcom

From: Mike Harrison 
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> Slightly off topic, but the SATCOM stuff the Air Force has is amazing.

Steven, 
What can you link to or share without fear of giving away national 
secrets, impuning the NSA.. etc..

I'm interested in many ways... for example, I know we have a utility in W. 
Africa using Sat coms to use Juice and are impressed with how it works in 
a high latency environment. I know they are on 64k links with 150ms to 
300ms round trips.

From memory: 
64k might be expressed as one half an ISDN connection,
ISDN is 2 B's (64k each) and a D or lower rate data/signalling channel.
Multiple B's (64k) can be bonded together for aggregate bandwidth
with that D (data) channel providing sync and bonding info.

I can see where that same structure could be used for any communications 
medium, just kind of suprised that it is. I'd like to know what the useful 
typical limits are in the military variations.





=============================================================== From: Stephen Kraus ------------------------------------------------------ Our SATCOM system utilizes basically two satellite channels to achieve ISDN capability (two 64 kb pipes) so that imagery data can be fed back to whoever wants it. This was our old system, via INMARSAT of Britian. We have a new SATCOM system, and I don't even have a clue of its throughput yet, but its going to be better.

=============================================================== From: Stephen Kraus ------------------------------------------------------ You have to realize (and I can only talk about non-classified non-INFOSEC stuff) that the JSTARS is just one big mobile observation post with IFF. It feeds ground troops valuable targetting and recon data, yes, but at the same time it sends anything it thinks is pertinent back to the DoD for further analysis, and it has to be able to feed this info steadily over a Satellite connection anywhere in the world. And from the size of the RAID arrays on the plane, you can assume its sending some pretty massive files.

=============================================================== From: Stephen Kraus ------------------------------------------------------ For instance, we actually have a phone on the plane. A good old fashioned phone. If someone sees something interesting, they actually call someone and say 'Hey, I saw such and such, I'm sending it your way for analysis'

=============================================================== From: Stephen Kraus ------------------------------------------------------ On that note, we us a packet accelerator for our service to decrease our latency.

=============================================================== From: Aaron Welch ------------------------------------------------------ Decrease latency? I have seen packet aggregators that can increase throughp= ut, but latency is a bitch to deal with over wireless links. On a differen= t note, we were pulling 10mbit down and 512kbit up in the middle of the ocea= n with Hughes satellite data service. Had 200-300ms ping times, but that is= awesome when you have nothing and are miles offshore. -AW atency. ote: phone. If someone sees something interesting, they actually call someone an= d say 'Hey, I saw such and such, I'm sending it your way for analysis' rote: C stuff) that the JSTARS is just one big mobile observation post with IFF. I= t feeds ground troops valuable targetting and recon data, yes, but at the sa= me time it sends anything it thinks is pertinent back to the DoD for further= analysis, and it has to be able to feed this info steadily over a Satellite= connection anywhere in the world. And from the size of the RAID arrays on t= he plane, you can assume its sending some pretty massive files. rote: SDN capability (two 64 kb pipes) so that imagery data can be fed back to who= ever wants it. This was our old system, via INMARSAT of Britian. hput yet, but its going to be better. te: . onal secrets, impuning the NSA.. etc.. n W. Africa using Sat coms to use Juice and are impressed with how it works i= n a high latency environment. I know they are on 64k links with 150ms to 300= ms round trips. . ns medium, just kind of suprised that it is. I'd like to know what the usefu= l typical limits are in the military variations.

=============================================================== From: Mike Harrison ------------------------------------------------------ It's a packet accelerator, like a particle accelerator, you send them around and around while speeding them up.... coil 500ft of Cat6e around a large induction motor. Do it just right, you'll see the same thing. The packets will fail to get responded to because they are moving so fast the other side can't see them. Ok, I'm just kidding. But I can see where compression, priority and good bandwidth management reduce apparent latency. Steven, I gotta know one thing: Was the phone RED ? Fun off-topic digression, unless you can tell us is if much *nix being used? I assume there are BSD and Linux variants in little black boxes doing specific things, routers, etc.. --Mike--

=============================================================== From: Stephen Kraus ------------------------------------------------------ OpenVMS and Debian are running around. VMWare running virtuals