6th European Conference - Academic Conferences

Solving for PK:
K
Pk
p0
K
1
k 0 k 0 2
p
k
1
2
k
p
0
k
1
p
p
0
k
Hind Al Falasi and Liren Zhang
k
k
K
K
1
0 2
1
2
1
1
0 2
k
k
k
*Where PK = PB = Probability an arriving packet is turned away due to full buffer = Probability of a
covert channel.
Figure 3: Markov chain model of the SAFP queue
6. Results
Figure 4 provides an overview of the relationship between the blocking probability and the size of the
SAFP buffer. We are assuming the simplest possible scenario, where the arrival rate is twice as fast
as the service rate. Starting with a buffer with size 0, the blocking probability is 1.
Figure 4: Pk vs. K
This is understandable, as at this point the SAFP is turning away every packet, due to lack of storage
place. When the size of the buffer is 2, we calculate a probability of a covert channel which is more
than 50%. While the probability slightly decreases as we increase the size of the buffer, we find that
12
(4)
(5)