Homework Questions Chapter 7 : Osi Data Link Layer

Homework Questions Chapter 7 : OSI Data Link Layer

(page 199) Concept Questions:

1. What are the two main jobs of the data link layer?

The Data Link layer prepares Network layer packets for transmission and control access to the physical media. Allows the upper layers to access the media using techniques such as framing, Controls how data is placed onto the media using techniques such as media access control and error detection.

2. What is the difference between a logical network and a physical network?

The physical topology is an arrangement of the nodes and the physical connections between them. A logical topology is the way a network transfer frames from one node to the next.

3. If the data link layer didn’t exist, what changes would be required of a network layer protocol such as Internet Protocol (IP)? Without the data link layer, a network layer protocol, like IP, would require provisions for connecting to every type of media that could exist along a delivery path.

Page 202 Concept Questions:

1. Compare and contrast Layer 2 addresses with Layer 3 addresses?

Layer 2 addresses- A switch works with MAC addresses at layer 2 of the OSI 7 layer model. Devices used on a Layer 2 Ethernet network include network interface cards, hubs, bridges and switches. Ethernet devices use 'burned in' MAC addresses to identify each host. These addresses are attached to network interface cards and cannot be changed

Layer 3 addresses- A Layer 3 switch is a high-performance device for network routing. A router works with IP addresses at layer 3 of the model. Layer 3 networks are built to run on, on layer 2 networks. In an IP layer 3 networks, the IP portion of the datagram has to be read. This requires stripping off the datalink layer frame information.

2. Why is Layer 2 addresses not needed in point to point topologies?

A point-to-point topology connects two nodes directly together, as shown in the figure. In data networks with point-to-point...