Random SoapException: No connection could be made because the target machine actively refused it 127.0.0.1:8056

I have client and server on same machine.
Server is web service installed in IIS 7.
Web.config file for web service contains entry -   <add key="serverURI" value="tcp://localhost:8056/RemotingFactory.rem" />
Client is making call as - 
 private void ThreadPoolWorkerThreadImpl(object state)
{

...

//server call
 ErrMsg[] signalEventErrors = eventWebService.SignalMultipleEvents(producerToken, producerEventDataArray);

...

} 

So issue here is - 
Call to server is success but sometimes its faling for some period of time and after that connection is successful
below is exception trace - 
014-01-13 01:01:27,993 [10] [system] ERROR - ThreadPoolWorkerThread.ThreadPoolWorkerThreadImpl(): Call eventWebService.SignalMultipleEvents()
System.Web.Services.Protocols.SoapException: No connection could be made because the target machine actively refused it 127.0.0.1:8056
   at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
   at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)
   at HP.ProducerEventSignalService.EventWebService.EventWebService.SignalMultipleEvents(String eventToken, ProducerEventData[] producerEventData)
   at HP.ProducerEventSignalService.Support.ProducerEventSignalService.Manager.ThreadPoolWorkerThread.ThreadPoolWorkerThreadImpl(Object state)
2014-01-13 01:01:27,993 [10] [system] INFO - ThreadPoolWorkerThread.HandleAllFailures(): Unsuccessful Event Service Notification timed out (OutgoingEventsId: 91267107 BdId: 94768075 EventId: 2 IsOrphanedEvent: False)

What might be the reason here? I did lot of google but not able to find the exact root cause of the same.
Any help or pointers really appreciated.