INTERNETWORKING I
(SEMESTER 1)
CHAPTER 3 STUDY GUIDE
What is the definition of a physical topology?
The actual layout of
the wire (media) of a network.
What is the definition of a logical topology?
Defines how the media is accessed by the hosts and how the hosts communicate across the media.
What is the purpose of a server on a network?
It provides applications and data to the hosts on the network.
Why are some devices described as “Layer 7 devices”? Give an example of one.
Layer 7 devices work at all layers of the OSI model. They preform the entire process of encapsulation and decapsulation. One example is a computer; another is the Internet “cloud.”
At what layer does NIC function? What does a NIC do? What services does it provide?
Layer 2. It is the integrated circuit board that the cable (media) plugs into to allow the host access to the network. . It provides access to the media (cable).
At what layer does networking media function? Give three examples of media.
At what layer do hubs and repeaters function?
What is the difference between a hub and a repeater?
A hub has multiple ports on it to allow more than one computer access. A repeater only has one port in and one port out. Otherwise, they do the same thing. It is sometimes referred to as a multi-port repeater.
What do hubs and repeaters do?
They amplify and retime signals to “boost” them across the media.
At what layer do bridges and swtiches function?
Layer 2.
What is the difference between a bridge and a switch?
A bridge filters traffic based on MAC addresses. A switch does the same thing, only it can also segment the network into “mini” networks. It concentrates connectivity and guarantees bandwidth (by segmenting). It switches packets (data) from incoming ports to outgoing ports based on MAC addresses. Each port on a switch is like a “micro bridge.”
What do bridges and switches use to make switching decisions?
At what layer do routers function?
What is the definition of a router?
They are the most important traffic-regulating device in a network. They move packets based on IP (logical) addresses. They can make forwarding and switching decisions. They are considered intelligent devices.
What do we mean when we talk about the “Internet Cloud”?
A collection of devices that operating at all levels of the OSI model. It is the representation of a large group of details that can’t all be identified at a given time.
What do internetworking devices connect?
Describe the three layers used in the design model we use to describe connectivity.
·
The core layer
provides fast wide-area connections between geographically remote sites, tying
a number of campus networks together in a corporate or enterprise WAN. There
are rarely any hosts in the core layer.
· The distribution layer gives network services to multiple LANs within a WAN environment. This layer is where the WAN backbone network is found, and is implemented on large sites and is used to interconnect buildings.
·
The access layer
is usually a LAN or a group of LANs, typically Ethernet or Token Ring, that
provide users with frontline access to network services. The access layer is
where almost all hosts are attached to the network, including servers of all
kinds and user workstations.
What do we mean when we talk about “intelligent” devices?
Devices that can examine packets and their destination and source addresses and help guide them through the network. They cut down on broadcasts.
What is the order of encapsulation (Layer and encapsulation unit)?
a. Data (7)
b. Segment (4)
c. Packet (3)
d. Frame (2)
e. Bits (1)
What kind of cable do you use to connect one PC to another PC?
cross connect
What kind of cable do you use to connect a PC to a hub or switch?
straight through
Do hubs have IP addresses on the network? Why or why not?
No, because they are “transparent” devices on a network. They have no identity of their own.
What is a transciever and what does it do?
Also known as a Media Access Unit (MAU). It provides the interface between the AUI port of a station and the common medium of the Ethernet. The MAU, which can be built into a station or can be a separate device, performs physical layer functions including the conversion of digital data from the Ethernet interface, collision detection, and injection of bits onto the network.