28 Jan 15 - CCNA 4.3

4.3.1  Purpose of the Data Link Layer

 The Data Link Layer is responsible for the exchange of frames between nodes over a physical network media.

It performs two specific services:

• Accepts Layer 3 packets and packages them into frames
• Controls media access control and performs error detection

4.3.1.2  Data Link Layer is divided into 2 Sublayers:

Logical Link Control (LLC)
Media Access Control (MAC)

Watch this.  It concisely explains 4.3.1.2 -4.3.1.4

28 Jan 2015 - Fiber Optic and Wireless

Fiber Optics

 Please follow the link to the quizlet review for 4.2.3 covering
Types of Fiber
Fiber Connectors
Fiber Cables

Fiber Optic Cabling Review - Quizlet

UTP Versus Fiber

Wireless Media

Wireless is not restricted to conductors or pathways and provides great mobility.  However, it does have some concerns when designing a network:

Coverage Area
Interference
Security

4.2.4.2 - Types of Wireless Media

Quizlet Review on Standards:

IEEE 802.11 standards Review

Do: 
Lab 4.2.4. Packet Tracer - Connecting a Wired and Wireless LAN
Email Screenshot to s.grover@msad17.org

Lab 4.2.4.6 Viewing Wired and Wireless NIC Information.
Email Screenshot to s.grover@msad17.orgre

27 Jan 15 - CCNA Chap 4 Review 4.2

 Chap 4 Review 4.2 - Network Media

4.2.1 Copper Cabling
Copper Cabling is inexpensive, easy to install and has low resistance to electrical current, but is limited by distance and signal interference.

What is Signal Attenuation?
What are the 2 sources of interference that can distort an electrical pulse?
Define EMI and RFI.  What is Crosstalk?

How can electronic noise on a copper cable be limited?

There are 3 main types of copper media:

• 4.2.1.3 Unshielded Twisted Pair (UTP) terminated with RJ-45
• 4.2.1.4 Shielded Twisted Pair (STP) terminated with RJ-45

                      How does it differ from UTP
                      What are the 2 common variations
                      It's popularity declined with the decline of Token Ring networks, but the 10GB Ethernet standard has renewed interest in it.

• 4.2.1.5 Coaxial Cable

Although UTP has essentially replaced coax, which 2 installation types have adapted for its use?


4.2.1.6  What are the fire and electrical hazards associated with copper cable?

List some best practices to avoid these hazards.





4.2.2 - UTP Cabling

4.2.2.1  Review UTP specs: # of pairs, color-coding, twisting, wire gauge,.....
UTP does not use shielding.  How is the negative effect of crosstalk limited?
          What is Cancellation?
          How does varying the # of twist per wire pair enhance cancellation?

4.2.2.2  What are some of the elements defined by the TIA/EIA-568A standard?
              What distinguishes the difference between CAT 5 and CAT6 cable

4.2.2.3/4 Know the pin outs for straight through and crossover cables.
               Identify a properly terminated cable and a cable with a bad connector.
               When is straight through, crossover or rollover used?

4.2.3 Fiber Optic
How are bits encoded on a fiber optic cable?
Is fiber optic cable susceptible to EMI and RFI?
How is fiber optic used in the following industries:

•        Enterprise Networks
•        FTTH and Access Networks
•        Long-Haul Networks
•        Submarine Networks

4.2.3.2 - Identify and describe the components of a fiber cable.

Optical fiber is proof tested through a rigorous manufacturing process for strength at a minimum of 100,000 pounds per square inch.

Taking a break - Will link in a couple worksheets comparing multi and single mode fiber, and different connectors 

4 March 2015 - CCNA Chap 4 Review 4.1

Chapter 4 - Network Access  4.1 Physical Layer Protocols

Review

4.0.1.1 -

• Which 2 layers of the OSI model are so closely tied that the TCP/IP combines them into one layer?

•  What is the role of the data link layer on the sending device?  What does it do on the receiving device?

4.1.1
Terms related to the physical or wireless connection to a network:  WAP. ISR, LAN, NIC, WLAN

4.1.2
The OSI physical layer provides the means to transport the bits that make up a data link later frame across the network media.

What is the process that data undergoes from source node to destination?
Review the PDU encapsulation process

What are the 3 basic forms of network media?

4.1.3

The 3 functional areas that the physical layer addresses: Physical components, Encoding and Signaling

 

Define Encoding

Signaling:  

• What is the difference between Asynchronous and Synchronous signal transmission?
• What are the 3 commonly used modulation techniques?
•  

 Define Bandwidth

 

How does throughput differ from goodput?
What is latency?

4.1.3.4 What role do standards play in defining media?

DO:  4.1.3.5