Covesa and AUTOSAR DLT incompatibility

[8vp]

Hi,

We have a Covesa DLT Daemon node connected to an AUTOSAR DLT node (gateway config), and everything works OK, except the problem with the two write messages from DLT Daemon, which causes AUTOSAR to reject these messages.

In dlt-daemon, specifically for control messages (like GET_LOG_INFO or SET_LOG_LEVEL), implementation isn't using a single send call and dispatches them as two distinct TCP segments.

Write A: Standard Header + Extended Header. (1st segment is sent)

Write B: Payload (the actual control command). (2nd segment is sent)

AUTOSAR stacks are notoriously sensitive to this because they use a PDU router that expects the DLT length field to match the incoming packet size exactly. If it gets a "partial" packet containing only headers, it sees a length mismatch and drops it.

Our DLT Daemon version is 2.18.10 and AUTOSAR DLT version is 19-11. Can someone advise as to what the rational is for Covesa DLT Daemon implementation to use two writes when sending a command/control message out?

Any advise from the community on how this can be made to work, will be much appreciated, and is this a bug that needs to be fixed in DLT Daemon?

[3mbedded]

We have gateway DLT Daemons talking to passive DLT Daemon and that works OK in my setup for log level control messages, no issues seen.

[8vp]

thanks for your comments. Works well between DLT Daemons. The issue we face is the control messages between DLT Daemon and AUTOSAR DLT. AUTOSAR DLT drops the message because it is segmented as two messages (one for header and one for payload). DLT Daemon spec, specifies its compatible with R19-11 AUTOSAR version, but it seems like a bug to me?