SFDC Communication error
we are facing the following error intermittently while connecting to SalesForce.com.
'<There was a communication error when talking to Salesforce.com: Connection timed out: connect>' and
'<Cannot start session.
com.acta.adapter.salesforce.exceptions.UnexpectedErrorException: There was an unexpected error. Salesforce.com message is Too many requests waiting for connections...>'
the job runs fine when we re-run it after some time.
Kindly help if anyone knows what actually is causing this error and how could we solve this issue.