User manual

2 Network Administration
Have your MATL AB administrator ve rify that the license manager
is running and validate network services.
For more infor mation, see The MathWorks Suppo rt page at
http://www.mathworks.com/support and search f or
"license manage r error -15"
- If yo u have installed only Distributed Computing Toolbox, and you are
attempting to run a worker on the s ame machine, you will receive this
error because the Distributed Co mputing Eng ine i s not installed, and
therefore the worker cannot obtain a license.
Verifying Multicast Com m unications
Note Though DCT/MDCE Version 3 continues to support multicast
communications between its processes, multicast is not recommended and
might not be supported in future releases.
Multicast, unlike TCP/IP or UDP, is a subscription-based protocol where a
number of machines on a network indicate to the network their interest in
particular packets originating somewhere o n that network. By contrast,
both UDP and TCP packets are always bound for a single machine, usually
indicated by its IP address.
The main tools for investigating this type of packet are
tcpdump or the
equivalent on Windows (usually called
winpcap and ethereal), and a Java
class included with DCT/MDCE Version 3.0.
The class is called
com.mathworks.toolbox.distcomp.test.MulticastTe ster .Bothitsstatic
main method and its constructor take two input arguments: the multicast
group to join and the po rt number to use.
This Java class has a number of simple methods to attempt to join a specified
multicast group. Once the class has successfully joined the group, it has
methods to send m essages to the group, listen for messages from the group,
and display what it receives. The class can be used both inside MATLAB
and from a call to Java.
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