The SCTP association has been established between the 2 nodes. Node 1 has been able to send SCTP data to Node 2. But while Node 2 tries to respond to Node 1 data sctp_send() fails with error code EINVAL. But SCTP HEARTBEAT and HEARTBEAT ACK is getting exchanged between the nodes. Please tell me how to debug SCTP Data transmission error.

retVal = sctp_send(iActualSocFD,&event->data[sz],(size_t)event->len,(struct sctp_sndrcvinfo *) &sinfo,MSG_NOSIGNAL); if (retVal == -1) { LOG4CPLUS_FATAL(log,"Unknown Error"<<errno<<"SD"<<iActualSocFD) }

Its the same piece of product code which was working (sctp_send() successful) when it was compiled on RHEL 6 but now failing after upgrading to RHEL 7.6 .The network entity to whom the sctp packet is being sent is on RHEL 6 platform.Whether this is creating any issue ?I suppose backward compatibility should be supported.