đź“– IT Bible

Wide Area Network Technologies

Wide area network: Acts like a single network but spans across multiple physical locations.

  • WAN technologies usually require that you contract a link across the Internet with your ISP

Physical versus software-based WANs 

  • WAN router: Hardware devices that act as intermediate systems to route data amongst the LAN member groups of a WAN (also called WAN endpoints) using a private connection. WAN routers may also be called border routers or edge routers. These routers facilitate an organization’s access to a carrier network. WAN routers have a digital modem interface for the WAN, which works at the OSI link layer, and an Ethernet interface for the LAN.

  • Software-Defined WAN (SD-WAN): Software developed to address the unique needs of cloud-based WAN environments. SD-WANs can be used alone or in conjunction with a traditional WAN. SD-WANs simplify how WANs are implemented, managed, and maintained. An organization’s overall cost to operate a cloud-based SD-WAN is significantly less than the overall cost of equipping and maintaining a traditional WAN. One of the ways that SD-WANs help reduce operational costs is by replacing the need for expensive lines leased from an ISP by linking regional LANs together to build a WAN.

WAN optimization

There are multiple techniques available to optimize network traffic and data storage on a WAN: 

  • Compression: Reducing file sizes to improve network traffic efficiency. There are many compression algorithms available for text, image, video, etc. The sender and the receiver will need apps that offer the same compression/decompression algorithm to encode and decode the compressed files.

  • Deduplication: Prevents files from being stored multiple times within a network to avoid wasting expensive hard drive space. One copy of the file is kept in a central location. All other “copies” are actually file pointers to the single copy of the file. This saves valuable hard drive space, makes performing data backups more efficient, and reduces the amount of time needed to recover from data loss disasters. 

  • Protocol Optimization: Improves the efficiency of networking protocols for applications that need higher bandwidth and low latency. 

  • Local Caching: Storing local copies of network and internet files on a user’s computer to reduce the need to resend the same information across the network every time the file is accessed. Some WAN optimization products can cache shared files at one physical LAN location when groups of employees at the location tend to request the same set of files frequently.

  • Traffic Shaping: Optimizing network performance by controlling the flow of network traffic. Three techniques are commonly used in traffic shaping: 

    • bandwidth throttling - controlling network traffic volume during peak use times

    • rate limiting - capping maximum data rates/speeds

    • use of complex algorithms - classifying and prioritizing data to give preference to more important traffic (e.g., an organization might want to prioritize private LAN-to-LAN traffic within the organization’s WAN and give a lower priority to employees accessing the public Internet).