RAS Encryption?

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RadioGuy7268

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RAS = Restricted Access to System. Motorola recently made it a standard offering on every new MotoTrbo repeater.
 

gary123

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RAS is more like a 'secret' Password needed to access the system. It is now enabled in the default settings for the TRBO line of products.
 

UPMan

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RAS does not prevent scanners from monitoring the system. It prevents unauthorized two-way radios from transmitting on the system.

It can degrade, somewhat, scanner performance on RAS-enabled systems, as the scanner must disregard CRC errors in the data stream and could misinterpret the data stream in some cases.
 

exkalibur

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RAS does not prevent scanners from monitoring the system. It prevents unauthorized two-way radios from transmitting on the system.

It can degrade, somewhat, scanner performance on RAS-enabled systems, as the scanner must disregard CRC errors in the data stream and could misinterpret the data stream in some cases.
It also prevents unauthorized two-way radios from receiving the system.

You mean scanners "cooperate" with CRC checks? Could have surprised me given how absolutely poor their performance is on most digital systems.
 
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RadioGuy7268

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My limited understanding of RAS as offered by Motorola, is that it is enabled in two different levels.

Level 1 restriction is based upon a simple ID range check. The repeater can be restricted to only allow certain "blocks" of ID's to gain access to the repeater. Of course, the radios must have the proper frequencies and color codes, but if the repeater only allows ID#'s 1 through 99, someone with an ID of 101 would be denied from accessing the system. All units with the proper color code and frequency info could still receive.

Level 2 restriction for RAS is based upon a programmed Key that must match both the repeater and the mobile/portable radio unit. Without the correct Key code (and ID# if restricted as above using Level 1) No traffic is passed through either on the receiving radio or the repeater. Level 2 is pretty damn tight from what I've seen, and I'm not aware of any other manufacturer making RAS Key encryption restriction.
 

Forts

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Hytera does as well (actually they were doing the range limitations etc long before Moto was).

My Whistler scanner works great on RAS systems.... my BCD325P2 wouldn't work at all on a TIII system with RAS, but I believe this was maybe addressed in the last FW update.
 

exkalibur

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In the repeater codeplug, you can specify a range of radio IDs to either allow or reject (and you can have multiple entries. That isn't RAS, per say.

Currently the "Enhanced" encryption offering is 40 bit. The RAS key is actually considerably stronger than that, so your link control is more heavily protected than your voice. Unless of course, Motorola decides to sell AES to the North American market (ha, good luck!).
 

Forts

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In the repeater codeplug, you can specify a range of radio IDs to either allow or reject (and you can have multiple entries. That isn't RAS, per say.
Starting with the R8.0 release Hytera has what they call 'Over the air encrypt'. From the release notes:

Over the Air Encrypt
With this feature enabled, only the signaling frame transmitted over the air is encrypted. The receiving
radio cannot receive signaling further if it fails to decrypt the signaling frame correctly. In the repeater
mode, if the transmitting radio fails to satisfy the encryption requirements, signaling transmitted by it will
not be forwarded by the repeater, and the radio cannot receive the signaling or data forwarded by the
repeater.

This feature is developed to prevent unauthorized access to the system, to ensure the security of the
system.

To set related parameters in the CPS, go to:
 Conventional -> Digital Common -> Encrypt -> Over the Air Encrypt
 Conventional -> Channel -> Digital Channel -> Over the Air Encrypt Type
 Conventional -> Channel -> Digital Channel -> Only Receive Encrypt Air
 Conventional -> Channel -> Digital Channel -> Over the Air Encrypt Key
And naturally it's not compatible with RAS.
 

Forts

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Weird though that they enable RAS, but not encryption... Guess they don't mind people listening, just don't want them doing it with a 'real' radio or borrowing airtime on their repeater.
 

exkalibur

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Weird though that they enable RAS, but not encryption... Guess they don't mind people listening, just don't want them doing it with a 'real' radio or borrowing airtime on their repeater.
There are some locals here who try and hijack every system that hits the air. I don't blame operators for trying to protect their investment from these guys.
 
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