i had get this error while registering terminal.

Incoming XML 4 2353::10.2.11.27:0
<?xml version="1.0" encoding="UTF-8"?>
<RegisterTerminalResponse xmlns="http://www.avaya.com/csta">
<device>
<deviceIdentifier typeOfNumber="other" mediaClass="" bitRate="constant" xmlns:ns1="http://www.ecma.ch/standards/ecma-323/csta/ed2">2353::10.2.11.27:0</deviceIdentifier>
</device>
<code>-1</code>
<reason>Registration Reject reason: resourceUnavailable
Request rejected from switch with error code= 18309</reason>
</RegisterTerminalResponse>

please use the SAT command 'list trace ras ip-station xxxx' and observe the registration attempt. If the error message is not helpful in identifying the problem, please double check that you can register a 'hard' IP telephone to the extension you are trying to use with the DMCC Service.