Exception in Weblogic Application server

Hi,

I have a application running on weblogic server. i am getting these errors in logs very frequently. Could you please suggest any solution for this.

-02-09 10:02:32,346 ERROR [Main Thread] psn.properties.RemotePropertiesCache - Error occurred while attempting to retrieve property: 

default.jms.topic.ConnectionFactory. Returning default value.
javax.naming.CommunicationException [Root exception is java.net.ConnectException: t3://voasams1,voasams2:7502: Destination unreachable; nested exception is: 
    java.net.ConnectException: Connection refused; No available router to destination]

2011-02-14 10:14:40,649 ERROR [Transport Shepherd] psn.properties.RemotePropertiesCache - Error occurred while attempting to retrieve property: 

loggingevent.ExternalTransportError. Returning default value.
java.rmi.ConnectException: Could not establish a connection with 

8802516135776057077S:voasams2:[7502,7502,-1,-1,-1,-1,-1]:voasams1:7502,voasams2:7502:vfop6dom:ams-stream1-svr2, java.rmi.ConnectException: Destination 

unreachable; nested exception is: 

Any help would be appreciated.
Thanks in advance

Regards,
SiddheshK