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Harris / MA/COM / GE / Ericsson Forum For general discussion of MA/COM EDACS and ProVoice systems, including equipment.

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  #21 (permalink)  
Old 10-04-2013, 7:09 AM
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Hello Elroy
Please check you PM's.

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  #22 (permalink)  
Old 10-07-2013, 5:42 PM
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Yes, sorry I should have been more specific. ProFile is the OTAP for EDACS (Harris P25 too?)

There are several messages that can come down the control channel that a radio will reply to. Most of them can be set to ignore one way or another. But the stun message and ping messages cannot. If the LID that is in your radio gets sent one of those messages, it WILL try to reply. Thats why the safe bet is to stop it from being able to talk altogether.
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  #23 (permalink)  
Old 10-08-2013, 1:57 AM
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Sorry to post so long after i started the thread, Im trying to downgrade my radio but cant find the radio code or DSP files i need. does anyone know where i would go about finding those files?
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  #24 (permalink)  
Old 10-22-2013, 2:50 PM
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I think I remember seeing about multiple, same LID's on a system. If there are multiple of the same lid at one time the system can turn off that lid, or does it disable the radio and does it know which radio doesn't belong?

Say there are two radio with the same lid but only use one at a time would that raise suspicion?
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Old 10-23-2013, 10:08 AM
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Quote:
Originally Posted by MECS_1947 View Post
I think I remember seeing about multiple, same LID's on a system. If there are multiple of the same lid at one time the system can turn off that lid, or does it disable the radio and does it know which radio doesn't belong?

Say there are two radio with the same lid but only use one at a time would that raise suspicion?
Seeing where this is going, I am going to offer one thing and one thing only.... It is possible that "cloning a LID" could cause one of the radios with the same LID to not function properly. I personally have two radios that share a LID (one is a back-up and both are legitimate radios on the system) and can tell you from first hand experience that two radios operating on two talkgroups at the same time with the same LID creates issues. DO NOT consider doing this. It has been said time and time again on this forum, if you are not an authorized user of a system using a radio authorized by the system owner - you need to buy a scanner....
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Old 10-23-2013, 3:04 PM
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I'd like add a "ditto" to Disaster Guys post.

Duplicate LIDs can cause problems ranging from radios transmittting on the wrong talkgroup to talkgroups acting as if they've been patched together.

The spectre of duplicates LIDs causes my shop to keep detailed records and have multiple process controls to ensure that a LID is programmed into the correct radio and only exists in that one radio.

A duplicate LID can cost a shop hours of trouble shooting, records review and re-programming to to diagnose and correct, not to mention the disruption on the system to the system users; no enthuisist has the right to cause that havok within a system regardless of your stance on "public airwaves".

Thats my soap box and I'll step down now.
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Old 10-23-2013, 9:58 PM
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Thank you, very informative. I guess I was not specific enough. If the radio's are both authorized and one is a back-up and is the same as the other (talkgroups) and you only use one at a time is there still problems?
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  #28 (permalink)  
Old 10-23-2013, 10:18 PM
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Used one at a time there would be no problem. The problems ensue when they are both active.

Harris P-25 Unified Admin System database asks for the ESN of the subscriber radio and Im told there is way to lock the system down by ESN but I've never seen it in operation. EDACS has no such feature.
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  #29 (permalink)  
Old 10-24-2013, 6:25 PM
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While the future of using "wild" two way radios to listen to trunked systems may be very much in doubt, the reality is that right now the usage of such things is widespread.

I mean, it's REALLY widespread. I'm seeing people with their own radios more and more often, ordinary people who just like to listen. And some of them admit that they can program their own radios themselves.

I can, and I do. But I've been in the radio hobby/business since the mid 80s and work for a radio shop, and my usage of my radios includes legitimate authorized access to certain systems. If any radio of mine is not specifically authorized to transmit, you can bet that its transmitter is locked down tight in every imaginable way short of yanking parts out of the transmitter circuit. Deviation to zero, power output to zero, everything set to no affiliate, no TX. Go a step further and set each talkgroup to encrypted mode with no key. And even to a digital mode that's not provisioned in the radio's feature set.

That'll put about five layers of "transmit denied" between my radio and an unauthorized transmission.

Under such conditions as that, I'm not even certain that the radio can be inhibited. Would anyone care to test that? If the radio can't transmit any data to succesfully send the acknowledge message, will it still be inhibited when that command comes?

There are also tricks to be played with the LID of the radio. Allegedly it's possible to hack a LID of 0 into the radio which makes it non-inhibitable. I don't know how to do that or if it works.

If I use an ID I'm assigned, that's fine. If another radio isn't authorized, I know the ranges of IDs that are in use and I can randomly pick one in one of the unassigned ranges.

I think that MOST people who'd rather use a real radio than a scanner would LIKE to be sure that
their radio won't get them in trouble. So telling them how to set up their radio for stealth operation (it won't be heard, ever) is probably a very good idea because as long as systems are open for monitoring,
people WILL get radios and use them, no matter what any individual thinks of that. You can't stop it,
so you might as well help those people to listen SAFELY without causing system interference.

Harris software unfortunately lacks the amazing flexibility of programming that Motorola's Astro software packages offer. So using the famous "Hidden talkgroups" method of programming a radio to monitor safely is not really an option with Harris/Macom/etc radios. But then again, RPM/ProGrammer can be a lot simpler and easier to use than the Astro/Astro25/APX software, too.

The most effective tool Harris has to control access is the security built into the installation of RPM.
It seems to be pretty good at stopping unauthorized installs.
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  #30 (permalink)  
Old 10-24-2013, 7:53 PM
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"Under such conditions as that, I'm not even certain that the radio can be inhibited. Would anyone care to test that? If the radio can't transmit any data to succesfully send the acknowledge message, will it still be inhibited when that command comes?"

Just thinking about it, I'm not sure the system requires an ACK on the disable command. It would look for one so it could notify the Admin that the command had been received but I'm not sure that would stop a subscriber from responding to it.

I've got an Orion on my bench with a TX problem maybe I can setup a scenario and test this.
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  #31 (permalink)  
Old 10-25-2013, 4:55 PM
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Elroy I did my test.

I took an authorized radio, able to transmit and rcv and verified the radio was good. Then I lifted pin 5 on the PA off the circuit path so it was unable to transmit yet could rcv.

Then I sent a disable command thru the CSD and the radio was disabled, no rcv and would not repsond to inputs from the talk group selector, even though the CSD showed the radio as DISABLE PENDING.

I then re-enabled the radio thru the CSD, it took the enable command and would rcv calls, pin 5 was still lifted from the circuit.

So disabling transmit functions from a radio with a duplicate valid LID cannot stop an inhibit command if it is sent.
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  #32 (permalink)  
Old 10-25-2013, 6:40 PM
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Interesting news indeed.

Did you set up the radio for forced encryption on with no key loaded?

I would THINK that wouldn't make any difference UNLESS the firmware thought that the lack of a key
in forced encryption mode means "No transmissions unkeyed, period.".

If that was the case, I'd think that it's a flaw in the firmware.
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  #33 (permalink)  
Old 10-25-2013, 9:10 PM
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Quote:
Originally Posted by ElroyJetson View Post
Interesting news indeed.

Did you set up the radio for forced encryption on with no key loaded?

I would THINK that wouldn't make any difference UNLESS the firmware thought that the lack of a key
in forced encryption mode means "No transmissions unkeyed, period.".

If that was the case, I'd think that it's a flaw in the firmware.
No, I didn't get in the weeds on the programming. I think that if the radio is monitoring the control channel it will see the disable command and that's all she wrote.

If the valid radio turns on and affiliates that would trigger the system to send the disable command and catch the "muted" radio that way, But that would require some serious detective work to know that a radio was out there using a duplicated LID seeing how it would never announce it's presence.

From system management perspective, the few times I've suspected that radio outside of my control was using a duped LID I didn't send a disable command. If I killed the radio the user could just as easily duplicate another and cause the problem all over so I just reprogrammed my radio and moved on.
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  #34 (permalink)  
Old 10-26-2013, 8:08 AM
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Quote:
Originally Posted by LMR_Dude View Post
No, I didn't get in the weeds on the programming. I think that if the radio is monitoring the control channel it will see the disable command and that's all she wrote.

If the valid radio turns on and affiliates that would trigger the system to send the disable command and catch the "muted" radio that way, But that would require some serious detective work to know that a radio was out there using a duplicated LID seeing how it would never announce it's presence.
Well said. A disable command is a disable command is a disable command. Doesn't matter if the radio can transmit or the correct encryption key is loaded. As long as it receives the system, it can be inhibited. If the system doesn't receive the ack, it will just keep trying. Bottom line, your radio is dead.

A wise system admin could periodically send out disable commands to radio ID's not authorized for the system. Don't know if this is possible (I've heard it is) or how long it would take. I guess it could be done during periods of low traffic but I would think catching a unauthorized radio at these times might be slim.
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Old 10-26-2013, 6:49 PM
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OK, here's another oddball question:

Would it be possible to program up a radio with EDACS IP data instead of regular EDACS data, for a regular EDACS system, in the hopes that this may create a radio that can LISTEN but might hopefully be immune to being remotely disabled?

I've never explored EDACS IP as of yet. I can't help but wonder if it might not present a "safer" way to scan an EDACS system.
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