Advertisement Upgrade to remove ads

Chapter 5 IS 4440

LANs

Local area networks exist within a company's site. On the customer premises - office suite, office building, or other property owned by the corporation.

WANs

Wide are networks connect different sites within an organization or transmit data between organizations. Transmission beyond its premises.

Speeds of LANs

LANs bring 100 Mbps to 1 Gbps to each desktop. Shared by multiple users

Speeds of WANs

WAN speeds more typically vary from 1 Mbps to about 50 Mbps. Shared by multiple users.

Workgroup switches

Switches that connect hosts to the network.

Core switches

Switches that connect switches to other switches

Access Links

Transmission links that connect hosts to workgroup switches.

Trunk Links

Transmission links that connect switches to other switches.

MAN

metropolitan area network - type of WAN limited to a large city and its surrounding communities. Man prices per bit transmitted are lower than those of WANs with geographical scope. MAN speeds are higher than WANs but slower than LAN speeds.

Another name for Ethernet

802.3

802.3az task Group

Energy-Efficient Ethernet standards

802.3 working group

Ethernet Standards

802.1 Working Group

General Standards, including Security

802.11 Working Group

Wireless LAN Standards

IEEE Standards Association

802 LAN/MAN standards Committee

ANSI

American National Standards Insitute

ISO

International Organization for Standardization

Standards of Single networks

Single networks use standards at the physical layer and the data link layer.

NIC

network interface card - implements Ethernet on a specific machine or host

Possible states in binary and digital signaling?

Binary their are two possible states. Digital signaling there are few possible states (2,4,8, etc.)

Digital signaling vs Binary Signaling

In binary signaling, there are two possible states. One bit is sent in each clock cycle. In digital signaling, there are a few possible states (2,4,8, etc.) More than one bit is sent in each clock cycle.

Binary transmission is a type of digital signaling. Not all digital signaling, however, is binary signaling.

Clock Cycle

When a device transmits, it holds the signal constant for a brief period of time.

UTP wiring

4-pair unshielded twisted pair wiring.

Serial Transmission

Transmitting over a single pair of wires
1 bit per clock cycle

Parallel Transmission

Transmission over more than a single pair of wires.
1 bit per clock cycle per wire pair
4 bits per clock cycle on 4 pairs
100 bits per clock cycle on 100 pairs

Parallel means that transmission occurs on multiple paris, not just four pairs.

Attenuation and Noise

Attenuate - signal gets weaker
Noise - random energy from other objects on the wire

cross-talk interference

generated by the other wire pairs in the same bundle.

Cable quality

is indicated by its category number
example: Category 5e (e stands for enhanced)
Category 6 or Cat 6
Cat 6A

What is the limiting factor in LAN fiber distance?

modal dispersion - modes entering the core at higher angles will take longer to travel than the straight mode. If modal dispersion is too large, parts of the light from sequential light pluses will overlap, making the signal unreadable.

Quality measurement in UTP and LAN fiber?

UTP is expressed as a category number (5e, 6 or 6A.
LAN fiber is expressed modal bandwidth (MHz-km)

Core Diameter

50 micron fiber and 62.5 micron fiber. Smaller is better. Travels faster

Wavelength vs. Amplitude

Wavelength is peak of Wave to next peak of Wave how long. Amplitude is the strength or depth of the wave.

Multimode fiber

light modes can enter at various angles. 50 or 62.5 microns are multimode fibers.

Link aggregation

two or more trunk lines to connect a single pair of switches. Networking professionals call this bonding.

Limits on distance of Ethernet on UTP or Fiber.

The 100-meter Ethernet limit for UTP and the longer distance limits for fiber only apply to physical links between pairs of devices, not to end to end data links between hosts across multiple switches.

Maximum end to end distance in Ethernet network

There is no maximum end-to-end distance (data link distance) between pairs of hosts in an Ethernet network.

MAC frame

media access control frame or the Ethernet Frame.

MAC Addresses

Ethernet addresses or called physical addresses because physical devices (NICs) implement Ethernet at the physical, MAC, and LLC layers.

Minimum length for the data field?

no minimum length but if the data field is less than 46 octets long, then a PAD field must be added to bring the total length of the data and pad fields to 46 octets.

Ethernet organization

Ethernet requires a hierarchical switch hierarchy. In a hierarchy, there is only a single possible path between any two end hosts.

Why Ethernet's dominance in LAN technology

The fact that there is only a single possible path between any two end hosts in an Ethernet hierarchy makes Ethernet switch forwarding simple and therefore inexpensive. The low cost has led to dominance in LAN technology.

VLANs

Virtual LANs are groups of clients and servers that are allowed to communicate with each other but not with clients or servers on other VLANs.

What is 802.1Q

Frame tagging

TCI

Tag Control Information (TCI) field
VLAN addresses

Managed switches vs Regular switches

Managed switches are more expensive than non-managed switches, but they reduce management labor in large networks enough to more than offset managed switch purchased costs. Managed switches reduce overall costs.

POE

Power over Ethernet
provides up to 25 watts to attached devices. USB and phones already do this.

Cladding

glass core is surrounded by a thin glass cylinder called cladding

LAN Fiber

LAN Fiber Distance: 200 to 300 m, Light wavelength: 850 nano meters Type of Fiber: Multimode (thick core) Core Diameter: 50 or 62.5 microns
Primary Distance limitation: Modal dispersion Quality Metric: Modal Bandwidth (MHz-km)

Carrier WAN Fiber

WAN Fiber Distance: 1 to 40 m, Light wavelength: 1310 or 1550 nano meters Type of Fiber: Single-mode (thin core) Core Diameter: 8.3 microns
Primary Distance limitation: Absorptive attenuation Quality Metric: N/A

The Rapid Spanning Tree Protocol (RSTP)

backup link is deactivated until needed but can cause a loop. This helps prevent single points of failure in a network.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set