1. Briefly describe circuit, message, and packet switching. 2. What is a transactional switch? A…

1. Briefly describe circuit, message, and packet switching.

2. What is a transactional switch? A transparent switch?

3. Explain the following terms: permanent virtual circuit, virtual call, and datagram.

4. Briefly describe an X.25 call request packet.

5. Briefly describe an X.25 data transfer packet.

6. Define ISDN.

7. List and describe the principles of ISDN.

8. List and describe the evolution of ISDN.