[SNMP4J] Determining Cause of Communication Error

[Chuck]

I am working on an application that is using 
SNMP v1 to query a large number of devices
for 3 or 4 OIDs.

We are running into a performance problem since
we use retries for each read attempt and send
a new PDU for each OID.  Is there a way to
determine the cause of communications error
using SNMP4J?  I'd really like to determine
if there is no response or if an ICMP packet
was received indicating that port 161 is
unreachable.  Being able to determine the
cause of the communication error, other 
than timeouts, would go a long ways to
improving performance.

So far the only indication I've found of
determining a communication error is that
the ResponseEvent#getResponse() returns
a null if there was a problem.  This 
doesn't really tell if the port itself
is unreachable though. 


Thanks in advance,

Chuck