pi to bpm - Failed to call the endpoint: Error in call over HTTP: HTTP 0 null

hi

i am using pi 740 single stack system. the scenario is PI to BPM to 3rd party server.

If 1000 successful messages from PI to BPM , 5 messages fail from PI to BPM with below error -

Failed to call the endpoint: Error in call over HTTP: HTTP 0 null

SOAP: Call failed: java.net.SocketTimeoutException: Read timed out

MP: exception caught with cause com.sap.engine.interfaces.messaging.api.exception.MessagingException: java.net.SocketTimeoutException: Read timed out

Same scenario,same interface,same kind of message data 1000 messages are successful ,but 5 gets failed.

BPM URL -http://localhost:50000/MessagingSystem/receive/JPR/XI and it is working perfectly fine.

What could be the cause of this error from PI to BPM messages ?