A host transmits a packet of size 2000 bytes over a 10 Mbps link. What is the transmission delay in milliseconds (ms)?
$Tx = (2000 * 8 bits) / (10 * 10^6 bps) = 16,000 / 10,000,000 = 0.0016 seconds = 1.6 ms.$
In a Mesh network with 8 nodes, how many total duplex physical links are required?
$Links = N(N-1)/2 = 8 * 7 / 2 = 28 links.$
In a CSMA/CD network with bandwidth 1 Gbps and propagation delay 5 microseconds, what is the minimum frame size required in bits?
$L_{min} = 2 * Tp * B = 2 * (5 * 10^{-6} s) * (1 * 10^9 bps) = 10 * 10^3 = 10,000 bits.$
In pure ALOHA, if offered load $G = 0.5$, calculate the throughput S rounded to two decimal places.
$S = G * e^{-2G} = 0.5 * e^{-1} = 0.5 * 0.367879 = 0.1839 \approx 0.18.$
How many usable host IP addresses are available in a CIDR block 10.20.30.0/28?
Total addresses = $2^{32-28}$ = $2^4$ = 16. Usable hosts = 16 - 2 = 14.