Friday, January 16, 2015

Chapter 2: Connecting to the WAN Part 1

This chapter is very long, dry, and vocab heavy. It will be split into more parts that will be added as I upload my notes. After this chapter it gets to the fun stuff of actually doing hands on labs. Do this looking forward to PPP.

 

This chapter covers:

  • What is a WAN compared to a LAN
  • The physical technologies of WAN connections
  • Overview of WAN protocols briefly
  • Evolution of an organizations growth and network technologies

 

What is a WAN?

A WAN, or Wide area connection, is a network that spans a large area and is used to connect enterprise LANs to branch LANs and telecommuter sites. WANs are owned by a service provider and the organizations must pay a subscriber fee to use the connection.
Service providers are companies that provides access to other networks or the internet to its subscribers.
WANs differ from LANs, local area networks. LANs are privately owned by the company and are used to connect local devices in a small area.
WANs consist of different technologies to handle long distance connections. *The book says physical connections are not feasible but then will later go on about how the best WAN technologies are physical fiber cables. I believe what they meant to say is each company having its own physical connections are not feasible.*
The internet is more often used as a WAN connection between organizations. Using the internet is cheaper but comes at the with security risks. New technologies have been developed to make the connections more secure. *No public connection should ever be thought of as secure, even with security technologies in place. Just ask Sony.*

 

Why are WANs important?

Simply without WANs, LANs would be a series of isolated networks. As businesses expand they will need to communicate over large areas that a LAN cannot handle.

 

Examples of how Organizations use WANs:

  • Regional or branch offices need access to data on the central site.
  • Organizations need to share data with other organizations
  • Employees who travel or work from home need access to corporate data.
  • *Employees using the internet to check Facebook and shop online, while at work*

 

Examples of how consumers use WANs:

People use the internet. I think I know what they use it for.

 

Evolving Networks

Over time organizations grow and shrink and their networks need to change with them. As a company grows it puts increased demand on the network . The network must grow and adapt to meet the day-to-day needs of the company. The network technologies, protocols, and service providers must be carefully chosen to. Networks need to be optimized.

 

Small Office

  • Few employees
  • one location
  • shared resources
  • Use of DSL or Cable internet connection
  • Single LAN
  • Usually two-tier network design
  • Hire out IT work from managed IT companies or the DSL provider.
DSL, or Digital Service Provider, is an always-on connection that uses existing phone lines that provides IP services to subscribers. A DSL Modem is required to convert the signal from the DSL signal to the Ethernet signal at the subscribers location. The DSL Signal is transmitted to and from the Central Office.
DSL providers can also provide hosting services such as FTP, Email, and Web servers.
©2014 Cisco Press, Connecting Networks Companion Guide

 

Campus network

  • Small to medium sized business
  • Several hundred employees
  • Multiple departments
  • Larger building
  • Use of three-tier network design
  • Multiple LANs, separated by department
  • More likely to have in house IT department
  • Onsite dedicated servers for Email, data, and web based apps.
  • Have company intranet
  • Extranet to communicate to customer organizations
©2014 Cisco Press, Connecting Networks Companion Guide

 

Branch Networks

  • New projects in distant locations
  • Data center in use
  • Branch locations require Data center access
  • WANs now necessary
  • May use private leased lines and/or public internet
  • IT team needs to handle security problems of public connections
©2014 Cisco Press, Connecting Networks Companion Guide

 

Distributed Network

  • World Wide locations
  • Teleporting or virtual teams
  • Web-based apps for web conferencing, e-learning, and online collaboration tools
  • Use of site-to-site VPNs (virtual private networks)
  • Use of converged services and secure internet WAN to remote offices and individuals
 
©2014 Cisco Press, Connecting Networks Companion Guide

This chapter will be continued in Part 2.



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