L2CAP: Unknown error: 431 and 436

I am trying to work with L2CAP channels over BLE. The service discovery, PSM lookup (via characteristics) and such all work fine.

The channel connects and I am able to exchange a couple of packets before the input stream is closed unexpectedly.

Meanwhile, the console reports the following CoreBluetooth messages:

Code Block 
error	WARNING: Unknown error: 431
error	WARNING: Unknown error: 436


As far as I can tell these error codes are undocumented and the L2CAP documentation is scarce at best. Does anyone know what they mean?
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neilalexander
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For anyone else who finds this in the future, I have been advised that the error codes are as follows:

  • 431: Peer device requested an L2CAP disconnection

  • 436: Local device requested an L2CAP disconnection

Posted by
neilalexander
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  • Hello just a question how are you able to know which error code correspond to what ? I go also an error "722" but i didn't manage to interpret it.

    —
    fmeyer

  • How did you find to which error does the code belong ? I got another error code "722" but i'm not able to found what it mean.

    —
    fmeyer
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For anyone else who finds this in the future, I have been advised that the error codes are as follows:

  • 431: Peer device requested an L2CAP disconnection

  • 436: Local device requested an L2CAP disconnection

Posted by
neilalexander
Up vote reply of neilalexander Down vote reply of neilalexander
Post marked as solved

  • Hello just a question how are you able to know which error code correspond to what ? I go also an error "722" but i didn't manage to interpret it.

    —
    fmeyer

  • How did you find to which error does the code belong ? I got another error code "722" but i'm not able to found what it mean.

    —
    fmeyer
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We are experiencing this on Monterey. The Bluetooth Core Framework has changed significantly. I hope apple will fix it ASAP.

Posted by
pkiman
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  • Our product mocha keyboard has also sometimes stopped working with error 431. There is not a pattern. I can get the L2CAP session with some devices, but it fails with other.

    —
    mochasoft
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I'd applaud a proper mapping table in the documentation…

Posted by
DrMickeyLauer
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