The promise of Java was "Write once, run anywhere" (WORA), or more aptly, "Write once, run everywhere" (WORE).
Unfortunately, because Oracle, it is more "Write once, spend days beating head against the latest random platform changes, curse, poke at random things, eventually get it to kinda work."
There is a definite correlation to things made by the Sirius Cybernetics Corporation:
"It is very easy to be blinded to the essential uselessness of them by the sense of achievement you get from getting them to work at all
In other words - and this is the rock solid principle on which the whole of the Corporation's Galaxy-wide success is founded - their fundamental design flaws are completely hidden by their superficial design flaws." -- Douglas Adams.
Anyway, if you are still reading and determined to get your Avocent DSR1030 / DSR2030 / DSR4030 / DSR 8030 working under OS X, this worked for me (under the specific build of Java on the specific version of OS X, etc. YMMV):
Edit: "/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/lib/security/java.security"
jdk.certpath.disabledAlgorithms=MD2, MD5, SHA1 jdkCA & usage TLSServer, \
RSA keySize < 1024, DSA keySize < 1024, EC keySize < 224
jdk.tls.disabledAlgorithms=SSLv3, RC4, MD5withRSA, DH keySize < 1024, \
EC keySize < 224, DES40_CBC, RC4_40, 3DES_EDE_CBC
jdk.certpath.disabledAlgorithms=MD2, RSA keySize < 1024, DSA keySize < 768, EC keySize < 224
jdk.tls.disabledAlgorithms=SSLv3, RC4, DH keySize < 768, EC keySize < 224, DES40_CBC, RC4_40, 3DES_EDE_CBC
Note that this changes the DSA keySize parameter from requiring 1024bit or longer to allowing 768 bit. This is not great security practice, but I only use Java for this app, and so I've decided it is a tradeoff I'm willing to make. In theory, this could be configured with a wrapper script (or possibly handing in -D options on the CLI), but Java (and Avocent) has made my sufficiently annoyed that I'm not willing to spend more time on this.