ACtE08 · Chapter 8Basic Electrical & Electronics🏛️ Past Licensure QuestionID: c663730b
In a connection-oriented virtual circuit packet-switching network, each packet header contains a:
In a connection-oriented virtual circuit packet-switching network, each packet header contains a:
Multiple Choice Options
- A
Full global IP address
- B✓ Correct Option
Virtual circuit identifier (VCI)
- C
MAC address
- D
Port number
Detailed Technical Solution & Explanation
In connection-oriented virtual circuit packet-switching networks (e.g., X.25, Frame Relay, ATM), an initial call setup phase establishes a fixed logical path through intermediate switches and assigns a local Virtual Circuit Identifier (VCI) for each link. Subsequent data packets carry only this short local identifier rather than full global network addresses.
Option Analysis:
•
Option A (Full global IP address): Incorrect. Used in connectionless datagram networks (such as standard IP routing) where routers evaluate the complete global destination on every packet.
•
Option B (Virtual circuit identifier (VCI)): Correct. Packets in virtual circuit networks carry a short VCI label that switches use to index their internal routing translation tables.
•
Option C (MAC address): Incorrect. Operates at the Data Link layer for physical node-to-node framing across local links.
•
Option D (Port number): Incorrect. Operates at the Transport layer (Layer 4) to demultiplex traffic among host applications.
Reference: Mock Test 03NEC Licensure Syllabus