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laforge, 11/08/2022 11:16 AM
1 | 1 | laforge | h1. osmo-isdntap |
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3 | @osmo-isdntap@ is a small stand-alone [daemon] program that you can run to create recordings of ISDN calls. |
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5 | It is part of the [[retronetworking:]] project. |
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7 | The program works by passively decoding the ISDN D-channel, specifically the Q.931 call control protocol. Whenever a call is being set up, it starts to capture the B-channel |
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8 | timeslot allocated to that call. It creates two files, one for each of the two directions of the call. The files contain the raw transparent binary B-channel data. |
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10 | Currently the only supported ISDN hardware/driver interface is DAHDI. |
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12 | Currently, only PRI (primary rate) ISDN interfaces are supported. |
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14 | h2. git Repository |
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16 | You can clone from the official osmo-isdntap.git repository using |
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17 | <pre> |
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18 | git clone https://gitea.osmocom.org/retronetworking/osmo-isdntap |
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19 | </pre> |
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21 | There is a web interface at <https://gitea.osmocom.org/retronetworking/osmo-isdntap> |
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24 | h3. Converting recordings to audio |
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26 | If you'd like to convert any of the recorded files to audio, you can use the following example |
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27 | command to do so: |
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28 | <pre> |
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29 | sox --channels 1 --type raw --rate 8000 -e a-law isdntap-03012342111-03012343038-20221016-212558-8-tx.raw output.wav |
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30 | </pre> |
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31 | The generated `output.wav` file can then be played back with any standard audio player. |