LL Control procedure Indication is still transmitted after Instant expiration

RE: LL Control procedure Indication is still transmitted after Instant expiration

Hung Bui — Fri, 24 Jul 2026 08:18:56 GMT

Hi Tovms,

Please correct me if I'm wrong. My understanding is that you want the central device not to continue to retransmit the LL Control Indication packet if the instance has passed, correct ?
The thing is that the central only retransmit this packet if it's not received an ACK from the peer device.

By spec, the central can not move on to transmit a new packet if the pervious packet is not ACKed, eventhough the packet is obsoleted. The flow control (ack and nack) is handled regardless of the content of the packet on the above layer.

So I don't think in this case the behavior of the softdevice stack can be changed.

RE: LL Control procedure Indication is still transmitted after Instant expiration

Tovms zhangsan — Fri, 24 Jul 2026 01:39:40 GMT

Hi, i'm also update to latest main branch in nrf repo, also have same problem.

RE: LL Control procedure Indication is still transmitted after Instant expiration

Hung Bui — Thu, 23 Jul 2026 12:56:30 GMT

Hi Tovms,
I will take a look but could you provide us more info about the version of the SDK you are using ?
I assume CONFIG_BT_LL_SW_SPLIT=y is not set (so that Nordic softdevice controller is used).

RE: LL Control procedure Indication is still transmitted after Instant expiration

Tovms zhangsan — Thu, 23 Jul 2026 01:50:38 GMT

devzone.nordicsemi.com/.../ncs_5F00_softvice_5F00_llcp_5F00_timeout.btt