11 11, 2016

Understanding SN and NESN in a BLE Link Layer packet

By | 2017-06-16T03:18:09+00:00 November 11th, 2016|Categories: BLE technology|Tags: , , , , |0 Comments

In my previous video looking at connection data captured via a BLE sniffer, I missed explaining two bits in the data that can be confusing to understand. The bits are the SN and NESN in the LL data packet. A few notes to better understand these bits: NESN and SN are used for data flow and making sure data is not missed (ACKs and NACKs). NESN and SN are looked at independently When the device sends a packet, the NESN is the next expected SN from the other side in the next packet coming back. When the device receives [...]