Infection Traffic Tracking in Performance Models

1. CDA6530: Performance Models of Computers and NetworksProject 3 Q&A TexPoint fonts used in EMF. Read the TexPoint manual before you delete this box.: AAAAAAAAAAAA

2. m = 300; n =300; • Structure definition in Matlab: • Node=struct('status', zeros(m,n), 'infectTime', zeros(m,n), 'InfectOtherTime', zeros(m,n)); • Or you can define: • NodeState = zeros(m,n); • NodeInfectTime = zeros(m,n); • NodeInfectOtherTime = zeros(m,n);

3. Multiple Way to Remember Infection Traffic • Define a queue variable to remember: • Generated infection traffic source (or destination) • Active time (when the source passes the traffic to all its neighbors, or when a vulnerble node receives the traffic) • Quite complicated since the event queue is very dynamic

4. Multiple Way to Remember Infection Traffic (my approach) • Use each infected node variable to remember when its outgoing infection traffic reach its neighbors • NodeInfectOtherTime(i,j) save the time for infection traffic reaching the node(i,j)’s neighbors

5. How to determine neighboring nodes? • You don’t need the code to remember the topology since it is so regular • Node(a,b)’s 4 neighbors: • Upper node: (a-1,b), Down node: (a+1, b) • Left node: (a,b-1), right node: (a, b+1) • Make sure you check if any of the above 4 nodes are non-exist • For S2, you also need to check if the node is one of those 10 shortcut nodes • If yes, considering the 5th neighboring node

6. How to decide the simulation end time? • At current discrete time k, check all nodes: • If all (NodeInfectOtherTime(.,.) < k), then stop • It means there does not exist any future infection traffic anymore

7. Infection Activity from sending node angle • At current time t: • If the NodeState(j,k) == ‘infected’ • If the NodeInfectOtherTime(j,k) == t, %the node infection traffic reach its neighbors now! • Check all its neighbors to see if any neighbor is infected now, if the neighbor node(a, b) is infected now: • NodeState(a,b) = infected; • NodeInfectTime(a,b) = t; • generate Poisson distr. delay time x; • NodeInfectOtherTime(a,b) = x +t +1; • If NodeState(j,k) == ‘vulnerable’ • Do nothing

8. Two Actions for Every Infected Node • Act 1: when node(a,b) becomes infected at current discrete time t • Change its status: NodeState(a,b) = INFECTED; • Assign: • NodeInfectTime(a,b) = t; • x = PoissonGenerator(); • NodeInfectOtherTime(a,b) = t + x + 1; • Act 2: when an infected node delivers infection traffic to its neighbors • When? if (NodeState(a,b) == INFECTED && t == NodeInfectOtherTime(a,b) ) • Check each of its neighbor: • If neighbor node(c,d) is vulnerable and will be infected? • Run Act 1 for the node(c,d)

9. Record Your Simulation Time • startTime = cputime; • Run your simulation…. • simulateCPUTime = cputime – startTime;