LE Credit-Based for L2CAP Connetion-Oriented Channels - Initial Credit

[Adrian B.]

Hello,

I am working for a BLE central application where the packets are send using L2CAP Connection-Oriented Channels.
My development environment is based on nRF52 development kit, using the nRF5 SDK v17.0.0 and the SoftDevice s132.

The application was developed based on the IPSP Initiator Example (infocenter.nordicsemi.com/.../ble_app_ipsp_initiator.html) with some small changes.

Unfortunately I face up with a limitation related to the initial credit.

In my application during LE Credit Based Connection Request (LE CBCR) the initial credit is set to 1. Is there any way to increase the number of the initial credits that are sent during the LE CBCR?

Thank you!

[Simonr]

Hi Adrian

I believe you can increase the amount of initial credit by editing the amount of credits set in sd_ble_l2cap_ch_flow_control() in your application.

Best regards,

Simon

[Adrian B.]

Hi Simon,

Thanks for your reply.
I have tried by using sd_ble_l2cap_ch_flow_control(), but currently the peripheral does not handle the flow control frames (the peripheral application is in a development process) .

Therefore I supposed that it is a way to increase the number of initial credit during the Credit Based Connection Request.

Thank you.

[Simonr]

Hi again

You can find all ways to set the initial credit value in the Bluetooth Core Specification Chapter 4.22 and 4.23 | Vol. 3, Part A specifically I think. You can search for "initial credit" to skip to the relevant sections.

Best regards,

Simon

[Adrian B.]

Hi Simon,

In the Bluetooth Core Specification Chapter 4.22 | Vol. 3, Part  A, the initial credit can be in the range of 0 to 65535.

In the Nordic SDK & SoftDevice the initial credit is set to "1" during LE Credit Based Connection Request. I am wonder if this value can be changed using the Nordic SDK.

Thank you.

[raccoon]

Hello Adrian,

What do you mean by "the peripheral does not handle the flow control frames"?
What will the peripheral do after the initial credits are exhausted?