WOW NETWORK SIMULATOR Duke Lee, Mustafa Ergen, Jeff Ko WOW WOW UC Berkeley UC Berkeley

WOW Simulator Animator input Define geographical distribution Define the functional parameters of the network nodes. Define network layer protocols Define traffic characteristics down to each node. Simulator core Network Modules Drive the event. Analyzer output Statistical graphing tool. Visual Tracer output Packet-level visualization tool. (NAM)

WOW Simulator Finite State Machine Event Driven Simulation Seed State List Simulation Functions Handler Functions

WOW Event Scheduler CHANNEL INFO. NODE Application WTP –timers IP –DSDV, etc. Link Layer –Timers,WTRP Channel –Packet transmission Node Info –position –topology SCHEDULER PHSICAL LAYER LINK LAYER IP TCPUDP ICMP QUEUE Application

WOW Scheduler Algorithm struct event { struct event *next; struct event *prev; unsigned long expiration; unsigned long data; void (*handler)(unsigned long); }

WOW Event Scheduler add_timer( event *ev); delete_timer(event *ev); mod_timer(event *ev); while(1) { tmp=take_event(); update_clock ; update_position; tmp.handler(); } SIMULATOR Event Queue add_event take_event

WOW Event Queue Packet Transmission Timer initialization tx_1 Event Queue rx_5 rx_2 rx_1 CHANNEL Packet transmission timer_7 tm_7

WOW Simulator Functions update_topology(); record_topology(); record_transmission(); record_reception(); Record Function is a periodic event which periodically starts monitoring SIMULATOR Event Queue record_function record_topology Output Files record_transmission record_reception

WOW Architecture Overall Design DEV1 ANIMATOR GUI DEV2 SCHEDULER … DEV3 ANALYZER GUI VISUAL TRACER GUI SIMULATOR MODULE LINUX MODULES CHANNEL MODULE State List State List State List INFO

WOW Interface Initialize_simulation; Initialize_topology; Initialize_traffic; Initialize_record_function; Main Loop Network Module MONITORING CBR CHANNEL SCHEDULER [1] [2] [3] [4] [5]

WOW [1] CBR-Data Traffic used to send periodic packet to the module. sits in the Logical Link Control above the network module. transmit (received something from the top layer) –int tx_handler (struct device *dev, struct sk_buff * skb) receive –int app_rx (struct device * dev, struct sk_buff * inskb, unsigned short network_proto)

WOW [2] Scheduler used to send data to channel module transmit first schedule a event and wait about a transmission time. –int transmit (struct device *dev, struct sk_buff skb) called when the module get the event from the scheduler. – received something from the bottom layer. –void rx_handler(struct device *dev, struct sk_buff *skb)

WOW [3] Channel scheduler to channel –void _transmit (struct device * dev) channel go through for each node and assign packet reception for those who can get the packet. channel to scheduler –void add_timer (struct timer_list * timer)

WOW [4] Monitoring Functions I void record_topology (struct simulation_struct * siminfo, struct device *device_list, struct device * dev, float time, float difftime); void start_transmission (struct simulation_struct * siminfo, struct device * sender, float time); void end_transmission (struct simulation_struct * siminfo, struct device * sender, float time); void start_reception (struct simulation_struct * siminfo, struct device * sender, float time); void end_reception (struct simulation_struct * siminfo, struct device * sender, float time);

WOW [4] Monitoring Functions II void record_transmission (struct simulation_struct * siminfo, struct device * device_list, struct device * sender, unsigned char * packet, float time); void record_reception (struct simulation_struct * siminfo, struct device * device_list, struct device * sender, unsigned char * packet, float time); printpacketinfo (* packet); needed for different packet types.

WOW [5] Inside Functions Randomize Functions basic random function should be used for determinism. –unsigned long net_random(void);

WOW Conclusion Unique Simulator Functions Specific Handler Functions Linux Scheduler Functions General Event Type NAM

WOW NAM Allows backward and forward run Node variables: color,shape … Node marking Variable Tracing Annotation Node Exec Button Save frames as a movie

WOW Appendix I Transport protocol create sk_buff from output buffers While device drivers create them for incoming data. TCP IP MAC Dev. sk_buff

WOW Appendix II struct cbr_struct { struct cbr_struct * next; unsigned long start_time; struct device * source; struct device * dest; struct timer_list cbr_timer; int packetsize; int numpackets; int bandwidth; void * handler; }; struct timer_list { struct timer_list *next; struct timer_list *prev; unsigned long expires; unsigned long data; void(*function)(unsigned long); }; sk_buff sk – pointer to owning socket stamp – arrival time dev - pointer to receiving/transmiting device h- pointer to transport layer header nh- pointer to network layer header mac- pointer to link layer header dst – pointer to dst_entry cb –TCP per –packet control information len – actual data length csum- checksum protocol- packet network protocol truesize- buffer size head- pointer to head of buffer data- pointer to data head Tail- pointer to tail End- pointer to end Destructor-pointer to destruct function