Determine the maximum length of cable (in km) for transmitting data at a rate of 500 Mbps in an Ethernet LAN with frames of size 10,000 bits. Assume the signal speed in the cable to be 2,00,000 km/s

Assume that source S and destination D are connected through two intermediate routers labeled R. Determine how many times each packet has to visit the network layer and the data link layer during a transmission from S to D.

The transport layer protocols used for real time multimedia, file transfer, DNS and email, respectively are

Using public key cryptography, X adds a digital signature σ to message M, encrypts, and sends it to Y, where it is decrypted. Which one of the following sequences of keys is used for the operations?