SDR# TETRA Demodulator Trunk Tracking Demonstration

albert1987

Member
Joined
Jan 8, 2019
Messages
6
Any encrypted PDUs do not show any invalid elements hence the old message "PDU encrypted: Data incorrect!"
Anything showing after it was always wrong and there is no point in showing it.


Hi thewraith2008,
thanks for explaination. I understood that any data showed after "PDU encrypted: Data incorrect!" was always wrong, but this could be useful to see if some communications occured in an encrypted network and how much is used the monitored network. Do you think is useful to add a flag in order to enable/disable it in the next release?
 

thewraith2008

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Joined
Nov 22, 2016
Messages
1,867
Hi thewraith2008,
thanks for explaination. I understood that any data showed after "PDU encrypted: Data incorrect!" was always wrong, but this could be useful to see if some communications occured in an encrypted network and how much is used the monitored network. Do you think is useful to add a flag in order to enable/disable it in the next release?

OK, I think I understand.
I don't have encrypted traffic here so it's something I don't always look at.
I tried one of my IQ samples that had it. The "PDU encrypted: ........." is not show which what what your talking about I think.
Normally the option "Ignore encrypted data" will do as you ask, but recent changes made it so this message was never shown.

The next release will restore this message as one of the following:
"PDU encrypted: MAC_resource (SCK-VN is even) on timeslot 1" for Class 2 cell.
"PDU encrypted: MAC_resource (SCK-VN is odd) on timeslot 1" for Class 2 cell.
"PDU encrypted: MAC_resource (CCK-id is even) on timeslot 1" for Class 3 cell.
"PDU encrypted: MAC_resource (CCK-id is odd) on timeslot 1" for Class 3 cell.

Not sure if that message makes sense to anyone.
MAC_resource is MAC PDU Type. During test only this type showed up. (Others could be MAC_frag, MAC_frag_end)
The "SKN-VN" and "CCK-id" is what the "Encryption mode" element is if cell is class 2 or class 3.
Maybe the wording can be changed.

As a side affect of investigating the above I found that encrypted voice was heard (in 'Auto') even if the option "Listen only clear speech" was enabled.
I added some hacked together code that makes an assumption that any encrypted control PDUs in the same timeslot as the voice traffic will then assume the speech is also encrypted and will be blocked. Why go to the effort of encrypting the PDUs and not the speech. Seemed to work in test.
 

syscodec

Member
Joined
Feb 20, 2019
Messages
22
E.g. I see lots of PDU's like PDU encrypted Type:UDT-3 Data: xxxxxxxxxxxxxxxx (64-bit) in which only last numbers change (increment, these are e.g. task done messages with task number incrementing (it is database table key and it is not encrypted because if you see the number it is just number if you dont have access to the database)
 

hamradionl

Member
Joined
Mar 23, 2014
Messages
730
syscodec
Very good and interesting point, you are writing,
Lets show all info and possible with some Click ON/ OFF boxes let TTT viewer decide if he want to see or view/shown these messages. If the TTT user have access to the database he is able to see or know the "standard messages". Example, i listening to my network and know that message 32 = "Task Ended" or message 12 = "Start Last Task" or message 10 = "Arrived last Task" or message 2 = "Free for new Task". So when i see on network a SSi who send one of these messages Numbers i know what it is. TTT user is able to make his own database messages numbers in TTT like using the Priority function Same why like SDRTrunk or Unitrunker.
 
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syscodec

Member
Joined
Feb 20, 2019
Messages
22
In a encrypted network (Cell air interface encryption flag 1) I quite often see messages like:
Type:UDT-4 Length:494 Protocol:Simple_location_system DATA:'0....' LocationSystemCodingScheme:35
Type:UDT-4 Length:899 Protocol:Concatenated_SDS_msg DATA:'0....'
 

iw2dtt

Member
Joined
Apr 1, 2014
Messages
28
Location
pavia
effettuate prove con nuova versione ora riproduce messaggi completi e posizione sds, sarebbe bello se possibile avere la possibilità di visualizzare solo i messaggi sds all'istante come se fosse in modalità remota, gruop - user-sds- grazie
 

syscodec

Member
Joined
Feb 20, 2019
Messages
22
Some of the pre-coded status numbers (user defined values) can be found from public documents published in the www sites of the authorities here where I live. System reserved values 0-32767 are more complex because those can be defined by terminal manufacturers and also when you purchase TETRA network. E.g. status code 0 (emergency) can be multi function operation in terminal. When you push red (emergency) button e.g. any one or any combination of the three pre-defined operations could happen (this can be programmed so it can be different in different terminals in network). 0 status is always sent but much more can happen.
 

hamradionl

Member
Joined
Mar 23, 2014
Messages
730
effettuate prove con nuova versione ora riproduce messaggi completi e posizione sds, sarebbe bello se possibile avere la possibilità di visualizzare solo i messaggi sds all'istante come se fosse in modalità remota, gruop - user-sds- grazie
carried out tests with new version now reproduces complete messages and sds position, it would be nice if possible to have the ability to view only the messages sds instantly as if it were in remote mode, gruop - user-sds- thanks

iw2dtt translate for you using Google translate ;)
https://translate.google.com/
 
Last edited:

Kenzi

Member
Joined
Mar 7, 2018
Messages
17
Does anyone have TETRA AES 128, 256 bit encrypted IQ samples with voice inside. Could someone upload the samples i would like to hear how the encryption sounds.
 

iw2dtt

Member
Joined
Apr 1, 2014
Messages
28
Location
pavia
carried out tests with new version now reproduces complete messages and sds position, it would be nice if possible to have the ability to view only the messages sds instantly as if it were in remote mode, gruop - user-sds- thanks
 

causeway74

Member
Joined
Jan 6, 2017
Messages
53
version 13 working great now - thanks! I'm having issues with recording. I noticed there are wav files generated but they seem to be corrupted. In TTT I see "the filename is invalid. Make sure the filename is not longer than 8 characters". Where is this value set or how can I resolve it?
 

thewraith2008

Member
Joined
Nov 22, 2016
Messages
1,867
version 13 working great now - thanks! I'm having issues with recording. I noticed there are wav files generated but they seem to be corrupted. In TTT I see "the filename is invalid. Make sure the filename is not longer than 8 characters". Where is this value set or how can I resolve it?

WAV files corrupted in what way?
If silence, then most likely you have not set it up correctly. Have a look at "TTT_Set-up_manual.pdf" section "Configuring for Recording calls"
Method #2 is the preferred way.

As for the error:
Most of the filenames are pre-determined like the record files.
The created log files are pre-determine and include main carrier # in filename.
The WAV filenames are generated from Time, Call ID and GSSI.

Does this crash TTT?
How often does this occur?
Is there a error number with the message?
When does this error occur. At program start, after period of time, on closing, after changing a option?
What is TTT mode and it's selected options.

How long is the path (C:\SDR\TTT\) to TTT folder. This length + (subfolders) + filename length must not be longer than 255 characters.
(e.g. C:\SDR\TTT\record.txt ) This path is 21 characters long.

You could try and disable a couple options in TTT in stages to determine what section/file is causing the error.
- Disable "Create CC VC log"
- Disable "Create event log"
- Disable "Create Call Activity CVS"
- Disable "Enable SDS - Location Data (GPS)"
- Disable Recording



Latest version (v1.0.13) can be found here: Release post
 

albert1987

Member
Joined
Jan 8, 2019
Messages
6
OK, I think I understand.
I don't have encrypted traffic here so it's something I don't always look at.
I tried one of my IQ samples that had it. The "PDU encrypted: ........." is not show which what what your talking about I think.
Normally the option "Ignore encrypted data" will do as you ask, but recent changes made it so this message was never shown.

The next release will restore this message as one of the following:
"PDU encrypted: MAC_resource (SCK-VN is even) on timeslot 1" for Class 2 cell.
"PDU encrypted: MAC_resource (SCK-VN is odd) on timeslot 1" for Class 2 cell.
"PDU encrypted: MAC_resource (CCK-id is even) on timeslot 1" for Class 3 cell.
"PDU encrypted: MAC_resource (CCK-id is odd) on timeslot 1" for Class 3 cell.

Not sure if that message makes sense to anyone.
MAC_resource is MAC PDU Type. During test only this type showed up. (Others could be MAC_frag, MAC_frag_end)
The "SKN-VN" and "CCK-id" is what the "Encryption mode" element is if cell is class 2 or class 3.
Maybe the wording can be changed.

As a side affect of investigating the above I found that encrypted voice was heard (in 'Auto') even if the option "Listen only clear speech" was enabled.
I added some hacked together code that makes an assumption that any encrypted control PDUs in the same timeslot as the voice traffic will then assume the speech is also encrypted and will be blocked. Why go to the effort of encrypting the PDUs and not the speech. Seemed to work in test.

Hi thewraith2008,
yes, I'm talking about exactly to this ;)
In the previous release I was able to see this message: "PDU encrypted: ........." .
As soon as possible I will record an encrypted IQ sample for further investigation and send it via PM.
Thanks
 

thewraith2008

Member
Joined
Nov 22, 2016
Messages
1,867
I don't receive many private duplex calls and when I do it's usually only one sided.
Other ISSI is assumed to be on another LA or passed directly from uplink to destination ISSI via the wired infrastructure.

When I do see both ISSIs, usually they are one the same carrier but different timeslots.
Today I received a call were each ISSI where on different carriers. I suspected this but until now I hadn't seen it. Question answered(y)



Latest version (v1.0.13) can be found here: Release post
 

causeway74

Member
Joined
Jan 6, 2017
Messages
53
WAV files corrupted in what way?
If silence, then most likely you have not set it up correctly. Have a look at "TTT_Set-up_manual.pdf" section "Configuring for Recording calls"
Method #2 is the preferred way.

As for the error:
Most of the filenames are pre-determined like the record files.
The created log files are pre-determine and include main carrier # in filename.
The WAV filenames are generated from Time, Call ID and GSSI.

Does this crash TTT?
How often does this occur?
Is there a error number with the message?
When does this error occur. At program start, after period of time, on closing, after changing a option?
What is TTT mode and it's selected options.

How long is the path (C:\SDR\TTT\) to TTT folder. This length + (subfolders) + filename length must not be longer than 255 characters.
(e.g. C:\SDR\TTT\record.txt ) This path is 21 characters long.

You could try and disable a couple options in TTT in stages to determine what section/file is causing the error.
- Disable "Create CC VC log"
- Disable "Create event log"
- Disable "Create Call Activity CVS"
- Disable "Enable SDS - Location Data (GPS)"
- Disable Recording



Latest version (v1.0.13) can be found here: Release post

Ah, I forgot about the path limitation, although I thought this had changed in Windows 10. I moved the TTT folder to the root of C and recordings are now working just fine.
 
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