Q. X.25 protocol consists of
✅ Correct Answer: (C)
Physical, frame and packet levels
Explanation:
The X.25 protocol is a standard suite for packet-switched network communication and consists of three main levels:
- Physical Level – Defines the physical connection between devices (like cables, voltages, etc.).
- Frame Level (Data Link Layer) – Uses LAPB (Link Access Procedure Balanced) for error correction and frame synchronization.
- Packet Level (Network Layer) – Manages virtual circuits and handles the transmission of packets.
So, the X.25 protocol covers all three levels, making option (C) the correct choice.
Explanation by: Mr. Dubey
The X.25 protocol is a standard suite for packet-switched network communication and consists of three main levels:
- Physical Level – Defines the physical connection between devices (like cables, voltages, etc.).
- Frame Level (Data Link Layer) – Uses LAPB (Link Access Procedure Balanced) for error correction and frame synchronization.
- Packet Level (Network Layer) – Manages virtual circuits and handles the transmission of packets.
So, the X.25 protocol covers all three levels, making option (C) the correct choice.