error in SOAP reciver Invalid SSL message, peer seems to be talking plain!

Hello Experts,

I am experiencing bit unusual behavior in my Proxy ->SOAP synchronous scenario, using SSL and related chain of certificate is installed

We are on SAP PI 7.3 dual stack.

Above scenario is working perfectly on our prod environment but how ever some time we use to get below error may be 2-3 times out of 100 calls

"MessagingException: iaik.security.ssl.SSLException: Invalid SSL message, peer seems to be talking plain!"

I am bit confused, why this error is coming only for few cases.

Any guidance or things i can check on PI configuration or anywhere else in network, please advise ..!

Regards,

Rajesh.