WAN ( Wide Area Network )

Posted on by nathan

A wide area network (WAN) is a computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries).[1] This is in contrast with personal area networks (PANs), local area networks (LANs), campus area networks (CANs), or metropolitan area networks (MANs) which are usually limited to a room, building, campus or specific metropolitan area (e.g., a city) respectively.

WANs are used to connect LANs and other types of networks together, so that users and computers in one location can communicate with users and computers in other locations. Many WANs are built for one particular organization and are private. Others, built by Internet service providers, provide connections from an organization’s LAN to the Internet. WANs are often built using leased lines. At each end of the leased line, a router connects to the LAN on one side and a hub within the WAN on the other. Leased lines can be very expensive. Instead of using leased lines, WANs can also be built using less costly circuit switching or packet switching methods. Network protocols including TCP/IP deliver transport and addressing functions. Protocols including Packet over SONET/SDH, MPLS, ATM and Frame relay are often used by service providers to deliver the links that are used in WANs. X.25 was an important early WAN protocol, and is often considered to be the “grandfather” of Frame Relay as many of the underlying protocols and functions of X.25 are still in use today (with upgrades) by Frame Relay.

Academic research into wide area networks can be broken down into three areas: mathematical models, network emulation and network simulation.

Performance improvements are sometimes delivered via wide area file services or WAN optimization.

Several options are available for WAN connectivity:[2]

Option: Description Advantages Disadvantages Bandwidth range Sample protocols used
Leased line Point-to-Point connection between two computers or Local Area Networks (LANs) Most secure Expensive PPP, HDLC, SDLC, HNAS
Circuit switching A dedicated circuit path is created between end points. Best example is dialup connections Less Expensive Call Setup 28 – 144 kbit/s PPP, ISDN
Packet switching Devices transport packets via a shared single point-to-point or point-to-multipoint link across a carrier internetwork. Variable length packets are transmitted over Permanent Virtual Circuits (PVC) or Switched Virtual Circuits (SVC) Shared media across link X.25 Frame-Relay
Cell relay Similar to packet switching, but uses fixed length cells instead of variable length packets. Data is divided into fixed-length cells and then transported across virtual circuits Best for simultaneous use of voice and data Overhead can be considerable ATM

Transmission rates usually range from 1200 bit/s to 24 Mbit/s, although some connections such as ATM and Leased lines can reach speeds greater than 156 Mbit/s. Typical communication links used in WANs are telephone lines, microwave links & satellite channels.

Recently with the proliferation of low cost of Internet connectivity many companies and organizations have turned to VPN to interconnect their networks, creating a WAN in that way. Companies such as Cisco, New Edge Networks and Check Point offer solutions to create VPN networks.

Viwawa

Posted on by nathan

Viwawa

Slogan

 : WHY PLAY ALONE?

Type of site

 : Games

Available language(s)

 : English
: Simplified Chinese
: Traditional Chinese
: Việt Nam

Owner

 : Pendulab Private Limited

Current status

 : Active

Viwawa is a portal for casual browser-based multiplayer online games and creation of avatars called Wawas developed by Pendulab Private Limited. The company is based in Singapore.

All games developed by Viwawa are multi-player and casual in nature.

  • Stwack – an original stickman fighting game
  • Big 2.5 – a card shedding game popular in Asia, also known as Big 2
  • MatchIt – a memory card game
  • Checkmate – International Chess in 2D and 3D
  • Wahjong – Mahjong with Singapore rules and Hong Kong rules
  • Sushido – a match 3 game where chefs compete to serve sushi to their customers.They must match 3 identical ingredients horizontally/vertically.
  • Zany Bridge – a card game based on contract bridge with rules abiding to Singapore Bridge
  • Wahlords – a strategy game where players attempt to bomb each other
  • Numeroid – a game similar to Puzzle Bobble with a requirement to construct mathematical equations
  • Dynasty Chess – Chinese Chess game with animated chess pieces
  • Groword – a game of forming words from a 5×5 board of alphabets
  • Harvest Time – a card shedding game popular in China, also known as Dou Di Zhu
  • Speedoku – a Sudoku game based on speed
  • DEFCON 1 – a Tower Defence game
  • Buffet Wars – a projectile game with a food theme
  • Bombs Away – a strategy game where you have to locate and destroy the entire enemy fleet of modern units before the enemy destroys yours with intuition.

Features

  • Viwawa extend their games to iPhones for Big 2.5 and a minigame for Sushido called Sushido Harvest.
  • In October 2010, Viwawa launched DevPals for game developers to create new games for the Viwawa Community.
  • In November 2010, Viwawa launched Viwawa Superfriends for better gaming in Viwawa.
  • In 2011 February, Viwawa added Charisma to all profiles linkage to Facebook and Twitter.

Business model

Viwawa games are essentially free to play. Revenue is derived through its games and avatar creation via micro-transactions over micropayment services such as PayPal, SMS mobile payments, Cherry Credits, MOLePoints and scratch cards.

History

Viwawa was launched in December 2007.

In 2008, Viwawa entered a partnership with Disney to create Disney content in their Avatar customization engine. At the same time, Viwawa also partnered with Garena to provide casual games to all Garena gamers.

In July 2009, World Cyber Games (Singapore) hosted the competition finals for Viwawa games.

In November 2009, Sanook! partnered with Viwawa to bring the games to their users in Thailand.

In 2010, Viwawa games Stwack and Sushido were featured in SG Gamebox, an initiative by the Media Development Authority of Singapore