The document discusses Distributed Queues Dual Bus (DQDB), a Metropolitan Area Network protocol defined in IEEE 802.6. DQDB uses a dual bus topology with upstream and downstream transmission directions. Nodes can transmit data packets using distributed queues and reservation tokens to control access to the transmission slots on the bus.

1. Metropolitan Area
Networks
• IEEE 802.6
• DQDB (Distributed Queues, Dual Bus)
WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998

2. IEEE- 802.6 (DQDB)
• Access Method: Dual Bas
• Directional Traffic
• Upstream and Downstream Station
• Transmission Slots
• Distributed Queue
• Ring Configuration
• Operation : DQDB Layers

3. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
DQDB Buses and Nodes

4. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
DQDB Data Transmission

5. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
Queues

6. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
Distributed Queues

7. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
Reservation Token

8. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
DQDB Rings

9. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
DQDB Rings

10. WCB/McGraw-Hill © The McGraw-Hill Companies, Inc., 1998
DQDB Layers

11. DRONACHARYA COLLEGE OF ENGINEERING, GURGAON
Computer Science & Engineering
Assignment
Semester- VI (I & II) Branch: CSE
Subject with Code: Computer Networks (IT-305-F)
----------------------------------------------------------------------------------
--
Q:1 What are Aloha and Slotted Aloha? Why they are required ?
Q:2 What is Frame Relay? Explain SONET/SDH in detail.