[ISC.0036.9107] Transport error encountered

Sometimes we are seeing the following error message in our portal logs when portal tries to connect to wM to call a flow services using java api:

com.wm.app.b2b.client.ServiceException: [ISC.0036.9107] Transport error encountered
at com.wm.app.b2b.client.Context.connect(Context.java:522)
at com.wm.app.b2b.client.Context.connect(Context.java:472)


com.wm.app.audit.AuditShutdownException:[BAA.0000.0044] Audit factory shutdown or not initializedcom.wm.app.au
dit.AuditShutdownException:[BAA.0000.0044] Audit factory shutdown or not initializedcom.wm.app.b2b.client.Serv
iceException: [ISC.0036.9107] Transport error encountered
at com.wm.app.b2b.client.Context.connect(Context.java:522)
at com.wm.app.b2b.client.Context.connect(Context.java:472)

It is not always happening and it happens 1 out of 7 transactions. Do you know what the reason could be?

Did any body encounter the below issue? For every 20 transactions, 1 transaction is failing with the error mentioned and portal team is complaining that wM is not sending any response.

Do any body have any suggestions or approaches to try diff options?