Subscription / Session Handling with Frequent Network Interruptions

[fritzz-98]

Hi Kevin, hope you are doing well.

In one of our projects we are experiencing constant network issues between the OPC UA client (our Milo implementation) and OPC UA server (some Siemens PLC). We create one session and one subscription for each PLC - as far as I understand, the session handling is done by the SDK and we should not manually interfere with that.
Regarding the subscription though, other than doing a resubscribe on onTransferFailed, are there any other recommended things we could implement in the client? I'm not sure if resubscribing on each watchdog timer elapsed event won't cause more issues for the server than it already has, so at this point I'm a bit lost. Obviously we cannot fix the network issues on the client, but I would like the client to handle such issues in the best way possible. If you have some tips or recommendation that would be great.

PS: I am using version 1.0.2 currently.

Thanks!

[kevinherron]

It depends... is the connection truly being lost, or is the connection keep alive mechanism forcing a reconnect?

You might also try a firmware upgrade for the PLC/server if it's not current.

Some logs or a Wireshark capture to provide more context about the issues would be useful.