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1. By
Mohammed Amer Al-Batati
2012

2.  In our network we can’t add more than two nodes.
 The reason is that, Node.ned defines only one input
gate and one output gate.
 The solution is to use gate vectors instead of single
gates.
 A more advanced solution is to use inout gate, which
is basically an input and an output gate glued together.

3.  Let’s modify our plan. When a node decides to
transmit a message, it have to select a random
destination. Therefore, we need to modify Node.cc
file.

4.  Goto to “mynetwork”-> add more nodes -> connect
them to each other then run the experiment. As
follows:

5.  Depending on the model domain, message objects
represent events, packets, commands, jobs, customers
or other kinds of entities.
 There are cMessage and cPacket Classes.
 The cPacket class extends cMessage.
 cPacket is used for network packets (frames,
datagrams, transport packets, etc.) in a
communication network, and cMessage is used for
everything else.
 For example, encapsulation and decapsulation
operations are only used with cPacket.

6.  cMessage *msg = new cMessage();
 cMessage *msg = new cMessage("timer");
 cMessage *msg = new cMessage("timer", kind);
 msg->setKind( kind );
 msg->setBitLength( length );
 msg->setTimestamp( simtime );
 int K = msg->getKind();
 int L = msg->getBitLength();
 simtime_t T = msg->getTimestamp();
 …etc

7.  cMessage *copy = msg->dup();
… one slide…
…one line…

8.  Example
IP
MAC
MAC IP

9.  Inspecting cMessage objects (previous code).

10.  Modify Node.cc code to include the encapsulation
example.
 Save, build and run.

11.  Inspecting cPacekt objects (new code).

12.  Example
 Assume that the following cPacket was received as
“MACdata”.
MAC IP
 After using the following decapsulation statement:
IP MAC

13.  Assume that you want to add your own header
between IP and MAC.
MyHeader
MAC IP
Name ID Year

14.  Assume that you want to add your own header
between IP and MAC.
MyHeader
MAC IP
Name ID Year

15.  From Project Explorer: right-click on myproject ->
New -> Message Definition (.msg) -> name it
(myHeader) -> Next -> Select New Message File ->
Next -> Finish.
 Add our fields:
 Save and Build.

16.  OMNet++ generates .cc and .h (myHeader_m.cc and
myHeader_m.h).
 Your needs are generated.
 How to use it.

17.  To use your new message: At Node.cc
1. Include the needed header.
2. Use “myHeader” as “cPacket”
3. That is it!
 Insert it between IP and MAC