Connection parameters: nRF Connect & finding them in Wireshark

[Vala]

Hi,

Could someone help me about the following questions?

Q1: What are the connection parameters set by the Android app nRF Connect? Can I change them?

Q2: How can I find out about these parameters via nRF Sniffer, more specifically, the connection interval? I know that the final decision is made by the Central (Initiator) and is reported in CONNECT_REQ packet. Does this packet contain the final settings? What types of packets should I look for to understand what the final connection interval is?

Q3: Can delta time parameter in the Wireshark be used to find the connection interval? Please see the attached images. In this connection, the CONNECT_REQ showed that the connection interval is 50 ms. Although, the delta time for the Rcvd Handle Value Notification, which I assume is the packet that contains the data (I recognized some the bytes that the Peripheral sent), shows a value of 150 us and 382 us for end to start and start to start parameters, respectively. On the other hand, there are some Empty Data PDUs that show a value of ~47000 us for these parameters, which makes sense according to the connection parameters set in the CONNECT_REQ packet. Is there anything that I don't understand correctly? Can the delta time parameters be used to find out about connection interval?

The Rcvd Handle Value Notification packet:

The Empty Data PDU packet:

-Vala

[Vala]

OK I guess I found the answers to the question No.3. There are some items that can show the start of the a new connection, and therefore 'delta time' showing the connection interval.

1- The event counter is updated for each connection.

2- All the transmissions in one connection is sent in one channel. Therefore, changing the number of the channel shows the termination of a connection.

Thus, the delta time of those packets which show a new connection should be checked for connection interval.