As a researcher, you have to enrich your knowledge in all the aspect of research such as algorithms, protocols, tools and etc. Meanwhile, this article is about the significance of droptail in network simulator. Let’s start this article with the important notes based on the droptail.
What is droptail?
The droptail is considered as the passive queue management algorithm whiles the packets that are dropped. The process of router is to accept and forward the packets that are arrived in the buffer space as per the availability of incoming packets. The incoming packets are dropped when the packets are arrived in the queue because it is full.
Consequently, our research professionals in this field have provided some highlights about the utilization of droptail in Ns2 and Ns3.
Droptail in Ns3
It is denoted as the fundamental first in first out (FIFO) queue to implement the tail drop while the queue is full. One attribute is defined through the DropTailQueue and that is MaxSize. The maximum queue size is shortened as MaxSize.
The characteristics of pattern usage is about to create the device helper to configure the queue type and attribute over the helper. We have highlighted the sample in the following for your reference,
PointToPointHelper p2p;
p2p.SetQueue ("ns3::DropTailQueue");
p2p.SetDeviceAttribute ("DataRate",
StringValue ("10Mbps"));
p2p.SetChannelAttribute ("Delay",
StringValue ("2ms"));
NetDeviceContainer devn0n2 = p2p.Install
(n0n2);
The SetQueue method of PointToPointHelper class is permitting the process with the specification of “ns3::DropTailQueue” in place of “ns3::DropTailQueue<Packet>”.
Droptail in Ns2
Initially, the topology is defined and the simulator object is created to start the simulation process along with the command. On the other hand, the trace file has to be opened with the initialization and define the procedure to start the nam in the case where the nam has to be run automatically. The following lines are inserted to code for the creation of four nodes.
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
Three duplex links are created among the nodes using the following section based on Tcl code.
$ns duplex-link $n0 $n2 1Mb 10ms DropTail
$ns duplex-link $n1 $n2 1Mb 10ms DropTail
$ns duplex-link $n3 $n2 1Mb 10ms DropTail
The user can save and start the process of script now and in this process when we notice, we found the topology looks a bit awkward in nam window. In addition, it you want to start this process again using the below mentioned Tcl script.
$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns duplex-link-op $n2 $n3 orient right
Full Duplex Link Using Droptail
The duplex links are created among the nodes while forming the ring in end and it is capable to acquire the utilization of duplex link instance with the specification of three parameters such as kind of queue (DropTail), delay (10ms) and data rate (1.5Mb) and that is enlisted in the below mentioned command.
$ns duplex-link $node1 $node2 1.5Mb 10ms DropTail
$ns duplex-link $node2 $node3 1.5Mb 10ms DropTail
$ns duplex-link $node3 $node4 1.5Mb 10ms DropTail
$ns duplex-link $node4 $node5 1.5Mb 10ms DropTail
The links have to be oriented among the nodes in correct process to acquire the appropriate alignment and the duplex-link-op instance is also used for the similar process.
$ns duplex-link-op $node1 $node2 orient left-down
$ns duplex-link-op $node2 $node3 orient left-down
$ns duplex-link-op $node3 $node4 orient right-down
$ns duplex-link-op $node4 $node5 orient right
The research scholars will be flabbergasted to know that still there are many more research significance based on droptail in network simulation and it is being developed every now and then depending on the real time requirements. We have well experienced research experts and technical developers who are always ready to help the research scholars at all the time. Thus, the research scholars can reach us to aid more.