L2CAP Connection Parameter update request by peripheral

RE: L2CAP Connection Parameter update request by peripheral

Karl Ylvisaker — Tue, 09 May 2023 11:59:13 GMT

[quote user="johnmjustin"]Thank you for working on this.[/quote]

No problem at all, I am happy to help! :)

[quote user="johnmjustin"]Yes I did remove all of these and tested but the connection breaks/disconnects after negotiation.[/quote]

What was the reason given for the disconnection? Was it the peripheral that terminated the connection?
I will check whether the SoftDevice always assumes that an update request will be sent if the parameters used are outside of the specified preference for the peripheral.

[quote user="johnmjustin"]

This works and the update parameter request doesn't happen.

I have set Minimum connection interval to 7.5ms

#define MIN_CONN_INTERVAL MSEC_TO_UNITS(7.5, UNIT_1_25_MS)

Is setting to 7.5ms legal value and soft device recognize it?

[/quote]

Great, I'm glad to hear that this negates your issue - there should indeed not be any connection parameter update requests if the connection parameters in use are within the preferences of the peripheral.

A 7.5 ms connection interval is the shortest legal interval, so this is an acceptable value for the MIN_CONN_INTERVAL.

Best regards,
Karl

RE: L2CAP Connection Parameter update request by peripheral

Justin — Mon, 08 May 2023 20:13:19 GMT

Thank you for working on this.

[quote userid="87869" url="~/f/nordic-q-a/99161/l2cap-connection-parameter-update-request-by-peripheral/424170"]Did you remove all of these when you tested this last?[/quote]

Yes I did remove all of these and tested but the connection breaks/disconnects after negotiation.

[quote userid="87869" url="~/f/nordic-q-a/99161/l2cap-connection-parameter-update-request-by-peripheral/424170"]An alternative way to stop these updates is just to increase the preferences of the peripheral to span the whole possible range (7.5 ms to 4 s) so that whatever connection parameters the central chooses will be within the peripheral preferences.[/quote]

This works and the update parameter request doesn't happen.

I have set Minimum connection interval to 7.5ms

#define MIN_CONN_INTERVAL MSEC_TO_UNITS(7.5, UNIT_1_25_MS)

Is setting to 7.5ms legal value and soft device recognize it?

RE: L2CAP Connection Parameter update request by peripheral

Karl Ylvisaker — Mon, 08 May 2023 08:37:47 GMT

Hello again, Justin

Thank you for your patience with this - I was out of office last week, but now I am back.

[quote user="johnmjustin"]Can you please check in the soft device code what triggers the parameter update request call ?[/quote]

The peripheral's parameter update request is configured using the following:

    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;

Did you remove all of these when you tested this last?

An alternative way to stop these updates is just to increase the preferences of the peripheral to span the whole possible range (7.5 ms to 4 s) so that whatever connection parameters the central chooses will be within the peripheral preferences.

[quote user="johnmjustin"]This happens only with the android and not seeing the parameter update request on windows BLE. [/quote]

Do you have sniffer traces of this? The peripheral does not know if it is connected to an android or a windows PC, so I would assume that this means that the connection to Windows already is using parameters within the preferred range of the peripheral.

Best regards,
Karl

RE: L2CAP Connection Parameter update request by peripheral

Justin — Tue, 02 May 2023 14:05:44 GMT

Hello Karl,

Any update on this out be great :)

Thanks

RE: L2CAP Connection Parameter update request by peripheral

Justin — Mon, 01 May 2023 19:20:40 GMT

Hi Karl,

Removing it is not solving the issue. The parameter update request is still being sent within a second after connection. Looks like removing it initializes the parameter with value zero.

Can you please check in the soft device code what triggers the parameter update request call ?

This happens only with the android and not seeing the parameter update request on windows BLE.

Thanks,

Justin

RE: L2CAP Connection Parameter update request by peripheral

Karl Ylvisaker — Fri, 28 Apr 2023 08:30:32 GMT

If you remove it from the conn_params_init it will default to not being sent.

Give this a try and do not hesitate to let me know if you encounter any issues or questions! :)

Best regards,
Karl

RE: L2CAP Connection Parameter update request by peripheral

Justin — Thu, 27 Apr 2023 17:10:09 GMT

[quote userid="87869" url="~/f/nordic-q-a/99161/l2cap-connection-parameter-update-request-by-peripheral/422690"]You can disable this request, which is configured in conn_params_init, if you would like to, or ignore it on the central side.[/quote]

How can I disable the request?

On the central side which is an android app we don't have easy way to ignore the request.

RE: L2CAP Connection Parameter update request by peripheral

Karl Ylvisaker — Thu, 27 Apr 2023 09:55:12 GMT

Hello,

The default behavior of the BLE UART peripheral example in the nRF5 SDK is to send a connection parameter update request 5 seconds into the connection, as configured by the FIRST_CONN_PARAMS_UPDATE_DELAY define. You can disable this request, which is configured in conn_params_init, if you would like to, or ignore it on the central side.

The peripheral may only ever request an update of the parameters, but the central can for any reason reject this request and continue to use whichever parameters it would like.

Best regards,
Karl