Network Simulator (ns-2)

NS (version 2) is an object-oriented, discrete event driven network simulator developed at UC Berkely written in C++ and OTcl (Tcl script language with Object-oriented extensions). It implements network protocols such as TCP and UPD, traffic source behavior such as FTP, Telnet, Web, CBR and VBR, router queue management mechanism such as Drop Tail, RED and CBQ, routing algorithms such as Dijkstra, and more. NS also implements multicasting and some of the MAC layer protocols for LAN simulations. NS-2 includes a tool for viewing the simulation results, called NAM.

NAM is a Tcl/TK based animation tool for viewing network simulation traces and real world packet trace data. The first step to use nam is to produce the trace file. The trace file should contain topology information, e.g., nodes, links, as well as packet traces. Usually, the trace file is generated by NS. During an ns simulation, user can produce topology configurations, layout information, and packet traces using tracing events in ns.

When the trace file is generated, it is ready to be animated by NaM. Upon startup, NAM will read the trace file, create topology, pop up a window, do layout if necessary, then pause at the time of the first packet in the trace file. Through its user interface, NAM provides control over many aspects of animation.
Network simulator can be learnt here and here.

Useful Keyboard Shortcuts

CTRL+C (Copy) 

CTRL+X (Cut) 

CTRL+V (Paste) 

CTRL+Z (Undo) 

DELETE (Delete) 

SHIFT+DELETE (Delete the selected item permanently 

without placing the item in the Recycle Bin) 

CTRL while dragging an item (Copy the selected item) 

CTRL+SHIFT while dragging an item (Create a shortcut to the selected item) 

F2 key (Rename the selected item) 

CTRL+RIGHT ARROW (Move the insertion point to the beginning of the next word) 

CTRL+LEFT ARROW (Move the insertion point to the beginning of the previous word) 

CTRL+DOWN ARROW (Move the insertion point to the beginning of the next paragraph) 

CTRL+UP ARROW (Move the insertion point to the beginning of the previous paragraph) 

CTRL+SHIFT with any of the arrow keys (Highlight a block of text) 

SHIFT with any of the arrow keys 

(Select more than one item in a window or on the desktop, or select text in a document) 

CTRL+A (Select all) 

F3 key (Search for a file or a folder) 

ALT+ENTER (View the properties for the selected item) 

ALT+F4 (Close the active item, or quit the active program) 

ALT+ENTER (Display the properties of the selected object) 

ALT+SPACEBAR (Open the shortcut menu for the active window) 

CTRL+F4 (Close the active document in programs that enable 

you to have multiple documents open simultaneously) 

ALT+TAB (Switch between the open items) 

ALT+ESC (Cycle through items in the order that they had been opened) 

F6 key (Cycle through the screen elements in a window or on the desktop) 

F4 key (Display the Address bar list in My Computer or Windows Explorer) 

SHIFT+F10 (Display the shortcut menu for the selected item) 

ALT+SPACEBAR (Display the System menu for the active window) 

CTRL+ESC (Display the Start menu) 

ALT+Underlined letter in a menu name (Display the corresponding menu) 

F10 key (Activate the menu bar in the active program) 

RIGHT ARROW (Open the next menu to the right, or open a submenu) 

LEFT ARROW (Open the next menu to the left, or close a submenu) 

F5 key (Update the active window) 

BACKSPACE (View the folder one level up in My Computer or Windows Explorer) 

ESC (Cancel the current task) 

SHIFT when you insert a CD-ROM into the CD-ROM drive 

(Prevent the CD-ROM from automatically playing) 

Dialog Box Keyboard Shortcuts 

CTRL+TAB (Move forward through the tabs) 

CTRL+SHIFT+TAB (Move backward through the tabs) 

TAB (Move forward through the options) 

SHIFT+TAB (Move backward through the options) 

ALT+Underlined letter 

(Perform the corresponding command or select the corresponding option) 

ENTER (Perform the command for the active option or button) 

SPACEBAR (Select or clear the check box if the active option is a check box) 

Arrow keys (Select a button if the active option is a group of option buttons) 

F1 key (Display Help) 

F4 key (Display the items in the active list) 

BACKSPACE 

(Open a folder one level up if a folder is selected in the Save As or Open dialog box)

Microsoft Natural Keyboard Shortcuts 

Windows Logo (Display or hide the Start menu) 

Windows Logo+BREAK (Display the System Properties dialog box) 

Windows Logo+D (Display the desktop) 

Windows Logo+M (Minimize all of the windows) 

Windows Logo+SHIFT+M (Restore the minimized windows) 

Windows Logo+E (Open My Computer) 

Windows Logo+F (Search for a file or a folder) 

CTRL+Windows Logo+F (Search for computers) 

Windows Logo+F1 (Display Windows Help) 

Windows Logo+ L (Lock the keyboard) 

Windows Logo+R (Open the Run dialog box) 

Windows Logo+U (Open Utility Manager)