WAN Technologies

1
Wide Area Networks
223990R
2
What is a WAN

• A WAN is a data communications network that
  operates beyond the geographic scope of a LAN
• WANs are used to connect LANs over a larger area
• A WAN uses data links provided by carrier
  services to access the Internet and connect the
  locations of an organisation to each other
• WANs generally carry a variety of traffic types
  such as voice, data and video
• Most WAN technologies operate at lower rate than
  LAN technologies

3
WAN Devices

• Router uses layer 3 address information to
  deliver the data on the appropriate WAN interface
• Switch used to connect more than 1 person to
  the router at the same time
• Modem used on an analogue local loop to
  establish a link to the destination
• Communication Server concentrate dial-in user
  communication and remote access to a LAN

4
WAN Standards

• Layer 1
• The physical layer protocols describe how to
  provide electrical, mechanical, operational and
  functional connections to the services provided
  by a communications service provider.
• Layer 2
• The data link layer protocols define how data is
  encapsulated for transmission to remote sites and
  the mechanisms for transferring the resulting
  frames.

5
WAN Usages

• WAN has had a enormous impact on the current
  state of technology and communications in the
  world, because of WANs every network on the face
  of this planet can be interconnected no matter
  the distance, this is done through various
  different links at various different speeds
  depending on the demand of the link, it is called
  this Internet. WANs have particularly benefited
  to Industries through its means of connecting up
  all of a companies remote sites through means
  such as a Leased Line.

6
WAN Security Privicy Issues

• Although there are many benefits and conveniences
  of WANs, there is are still issues which cause
  problems such as Spyware, Adwares, Viruses,
  Trojans etc, these malicious programs cause
  millions of dollars of damage every year.
  Nevertheless programs such as antivirus and
  firewalls will fend off such anomalies

7
Different WAN Technologies

• Analogue Dialup
• ISDN
• Leased Line
• DSL
• Cable Modem

8
Analogue Dialup

• Advantages
• Low cost dedicated line
• Can be used to backup to an offsite server
• Almost available everywhere
• Disadvantages
• Requires a modem to translate from binary signals
  to analogue
• Low data rates
• Long dialup connection time

9
ISDN

• Advantages
• Ideal for carrying voice and data
• More channels can open up to provide additional
  bandwidth when needed
• Disadvantages
• BRI ISDN can only transmit up to 128kbps
• High configuration is required to open up
  channels automatically

10
Leased Line

• Advantages
• Come in a huge range of different capacities
• Provides a dedicated line to the destination
• No latency and jitter
• Disadvantages
• Generally more expensive than dialup
• This more lines needed the greater the cost

11
DSL

• Advantages
• Uses the existing local loop
• Can achieve rates much higher than analogue
  dialup
• Relatively cheap
• Disadvantages
• A separate line is required for SDSL
• The local loop must be within 5.5km

12
Cable Modem

• Advantages
• Can achieve higher rates than DSL
• Readily available in most places
• Relatively cheap
• Disadvantages
• Uses a shared line therefore more people less
  bandwidth
• Installation can be expensive

13
Conclusions

• Although there are some disadvantages of WAN such
  as the security and privacy issues, these can be
  easily solved by antivirus software and
  firewalls, on the whole the advantages outweigh
  the disadvantages a great deal. Due to
  technologys such as WANs corporations can
  continue to expand in size providing more income
  into the economy as well as improving and
  simplifying the way we all use communications.