Installing Sun Java JDK and JRE in Ubuntu 10.10
While trying to install Sun java in ubuntu 10.10 ,I got the error
sudo apt-get install sun-java6-jre sun-java6-plugin
Reading package lists… Done
Building dependency tree
Reading state information… Done
Package sun-java6-jre is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
Package sun-java6-plugin is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package ‘sun-java6-jre’ has no installation candidate
E: Package ‘sun-java6-plugin’ has no installation candidate
SOLUTION :Install sun-java6 packages from the Canonical Partner Repository
- Adding a new source
sudo add-apt-repository "deb http://archive.canonical.com/lucid partner"
The above step may also be performed Add this line to your /etc/apt/sources.list file
deb http://archive.canonical.com/ubuntu maverick partner
sudo nano /etc/apt/sources.list # uncomment the two lines referring to "partner" - Run an update for the new repository
sudo apt-get update
- Now you can install the Sun JDK
sudo apt-get install sun-java6-jdk
Testing Java Runtime Environment
You’ll want to confirm that your system is configured properly for Sun’s JRE. This is a two-step process.
First, check that the JRE is properly installed by running the following command from a terminal.
umair@umair-VirtualBox:~$ java -version
java version “1.6.0_26”
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) Client VM (build 20.1-b02, mixed mode, sharing)
umair@umair-VirtualBox:~$
making simulation speedy and mac layer understanding
from http://www.cs.binghamton.edu/~kliu/research/ns2code/index.html#Eclipse
Understanding the implementation of IEEE MAC 802.11 standard in NS2
Download the document http://www.cs.binghamton.edu/~kliu/research/ns2code/note.pdf
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How to scale your simulation to more nodes (500 nodes) and speed it up ?
The implementation of the Packet data structure of NS2 does not match the realities. The packet in ns2 simulation keeps all packet headers for any protocols implemented in NS2. For example, a DSR routing packet may keep DSDV, AODV, or even a PING application header. For this reason, till today, a packet used in ns2 simulation, would have a header size around 40~64KB. And NO packet would be deleted to release the memory it holds until the end of the simulation.
So for a typical simulation with 100 nodes in ns2 around 1M packets exchanged (of course, you may reuse the packets already being freed throughPacket::free(Packet*). To learn the implementation of it, please check file common/packet{.h,.cc} ), you may hold 10% of it, 100K packets, and you may use a memory at least 100K*64KB -> 6.4GB, which definitely would crash your computer (even it is a super server).
So How you can do it? And how you can run a simulation like 500 nodes there? You have 2 ways to do:- Suggested by ns2 manual, putting the below codes in your tcl script
remove-all-packet-headers add-packet-header DSR ARP LL MAC CBR IP
to simulation a CBR application on UDP with DSR as routing protocol in a wireless ad hoc network (OOPS!, UDP is not a header. This method is effective, but it requires you to understand most packets header you need.
- Another way is my way, changing the tcl library for the packet headers. You may find the tcl library file for packet headers in ns2/tcl/lib/ns-packet.tcl, you may find a procedure starting as foreach prot {. You can comment out all the headers you don’t recognize, like all the Routing protocols you dont know, all Routers, all Multicast, all Transport Protocols except you need, all application layer protocols, some of the Wireless, some of theMobility, Ad-Hoc Networks, Sensor Nets and all the Other. Finally, you may just have all the below left
foreach prot { # Common: Common Flags IP # Transport Protocols TCP # Wireless ARP LL Mac # Mobility AODV } { add-packet-header $prot }If you are creating your own packet header, put them here.
Typically, after this way, you may just have a packet size as 256B. So even you have 500 nodes, and 10M packets need to be exchanged during the simulation. You just need 256MB (if 10% packets held) for it, which is lower than any common configuration of current PCs.
- Suggested by ns2 manual, putting the below codes in your tcl script
DSR : Segmentation Fault Solution
Change the interface queue (ifq) from Queue/DropTail/PriQueue or Queue/DropTail to CMUPriQueue
