In this article, we learn about the Wide Area Network, Purpose and Characteristics of WAN, How WANs Work, WAN Components and Terms, Types of wide area Networks, WAN Protocols, Advantages, Disadvantages, and WAN Security
Wide Area Network (WAN)
A computer network that connects several smaller networks, including Local Area Networks (LANs) and Metropolitan Area Networks (MANs), over a wide geographic area is known as a wide area network (WAN). A “network of networks” is what a WAN is essentially. The greatest WAN in the world is commonly said to be the Internet itself. WANs facilitate data sharing and communication across devices in disparate places, such as offices spread across cities or nations.
History of Wide Area Network
In the late 1950s, the U.S. Department of Defense created ARPANET (originally for the SAGE radar defense system), which is where WAN got its start. The first wide-area packet-switching network with dispersed control and the first to use the TCP/IP protocol suite, ARPANET connected Stanford Research Institute and UCLA, among other universities.
WAN Topologies: Common WAN topologies include:
- Star (Hub-and-Spoke): This type of network has a single hub, or central router, that gives distant networks access. The hub, which can be a single point of failure, is where all communication passes through.
- Full Mesh: Connects every network device to every other network device with direct links, offering redundancy and reliability.
- Partial Mesh: Connects some, but not all, pairs of devices, providing more redundancy than hub-and-spoke without the full complexity of full mesh.
Purpose and Characteristics of WAN:
- Extending Reach: Wide Area Networks (WANs) allow multi-location organizations to share resources, data, and applications as if on a local network, improving international communication and information sharing.
- Geographical Coverage: They can cover enormous areas, nations, or continents across a few kilometers to thousands of kilometers.
- Interconnection: They enable branch or regional office connections and distant corporate network data access for traveling staff.
- Resource Sharing: WANs allow users to share data and information across large geographic areas to access computer resources remotely.
- Centralized Management: Modern WANs can be managed and maintained from a single, central location, allowing IT leaders to deploy updates and troubleshoot remotely.
- Scalability: They facilitate smooth scalability, allowing businesses to quickly add or delete network connections from any place. They frequently make use of wireless and cloud technologies.
WAN vs. LAN:
A LAN serves one home, office, or workplace, while a WAN links many LANs over great distances. With Ethernet or Wi-Fi, LANs are cheaper and easier to set up and maintain. Typically, they share a single central point of Internet connection. For communication over LANs, WANs, on the other hand, might use a variety of networking technologies and depend on infrastructure that is not directly under an organization’s control. WANs have more capacity than LANs, although communication speeds may be slower over long distances.
How WANs Work:
By connecting a number of LANs over different geographic locations, WANs allow devices to share resources and information via a service provider. Because it is expensive to develop network infrastructure across different geographic boundaries, corporations usually rent services from third-party providers, including cable companies, private IP network operators, Internet service providers (ISPs), and telecommunications carriers.
Wide Area Network (WAN) architectures are founded on the Open Systems Interconnection (OSI) paradigm, which defines and standardizes telephony theoretically. This model’s seven layers are used by various networking technologies:
Layer 7 (Application layer): This layer determines how the user interacts with the network and is the one closest to the user. It is not aware of the network implementation and just contains the application logic. For instance, if your company has a calendar booking system, this layer handles booking logic like time zone conversion and invitation delivery.
Layer 6 (Presentation layer): The sixth layer, known as the presentation layer, gets data ready for network transmission. For instance, it provides encryption to prevent hackers from accessing your private meeting information while they are viewing your WAN.
Layer 5 (Session layer): This layer controls the sessions or connections between nearby and distant apps. It has the ability to start, stop, or open a connection between two devices. You are working from home, for instance, and your booking system is hosted on a web server in the central office. Following authentication, a connection is established between your machine and the web server via the session layer. Rather than being a physical link, this one is intellectual.
Layer 4 (Transport layer): The functions and protocols for data transmission are defined by the transport layer, which is layer four. The data is categorized and sent for transfer. Additionally, the data might be bundled into packets. For instance, the Transmission Control Protocol (TCP) categorizes communication into request and response packets when you visit the reservation website.
Layer 3 (Network layer): The third layer, known as the network layer, controls how data packets move over the network. For instance, it establishes the guidelines for load balancing, packet loss, and packet routing.
Layer 2 (Data link layer): The second layer, known as the data link layer, is in charge of creating protocols or communication rules for the physical layer operations. It chooses when to establish or break a direct link, for instance. Until packets arrive at their destination, this layer function sends them from one device to another.
Layer 1 (Physical layer): The first layer, known as the physical layer, controls the movement of unprocessed data in the form of digital bits, optical signals, or electromagnetic waves over various network transmission media, including wireless technologies and optical fibers.
At their core, WANs rely on data packets, routers, and endpoints (or end nodes).
Data packets: Small units of information containing the data and routing information, like source and destination.
Routers: Data packets are guided along paths throughout the network by routers, which are either physical or logical devices that choose the most efficient path. A WAN router, sometimes referred to as a border router or edge router, routes data packets between WAN locations, granting an enterprise access to a carrier network. In order to create a WAN, LANs must be connected via routers.
Endpoints: Physical devices connected to the network that exchange data, such as computers, laptops, smartphones, or servers.
Wan Components and Terms:
- Customer Premises Equipment (CPE): Equipment owned by the subscriber and located on their premises, such as routers.
- CSU/DSU (Channel Service Unit/Data Service Unit): A device that provides clocking by connecting DTE (such as a router) to a digital circuit (such as a T1/T3 line).
- Demarcation Point (Demarc): The precise point where the service provider’s responsibility ends and the CPE begins.
- Local Loop: Connects the demarc to the closest switching office.
- Central Office (CO) / Point of Presence (PoP): A building with telephone switching equipment connecting the customer’s network to the provider’s network.
- Toll Network: A trunk line within a WAN provider’s network, comprising switches and facilities.
Types of wide area Networks and Technologies:
Numerous technologies, including wired and wireless alternatives, are used by WANs. They are frequently categorized as circuit-switched, packet-switched, and point-to-point technologies.
Leased Lines (Dedicated/Point-to-Point): Direct network connections with assured capacity between locations that are rented from a major network operator. Both virtual and physical links are possible.
Circuit Switching: Just like a phone call, data only moves once an end-to-end connection has been made. Dial-up modems and ISDN are two instances.
Packet Switching: Messages can be transmitted separately and reassembled at their destination by using packet switching. This group includes technologies like Asynchronous Transfer Mode (ATM), X.25, and Frame Relay.
Tunneling: Creating a Virtual Private Network (VPN) by encrypting data packets as they travel over the open internet is known as tunneling. VPNs are more secure because they make a local host appear to be a member of a distant network by encrypting data and authenticating endpoints. For site-to-site communications, IPsec VPNs are frequently used.
Multiprotocol Label Switching (MPLS): A technique that routes data traffic based on predetermined labels, often for critical data across shorter or faster paths, improving network performance. It works between OSI layers 2 and 3 and can create a unified network over existing infrastructure.
Software-Defined WAN (SD-WAN): With the use of virtualization, overlay networks, application-level controls, and on-site hardware and software platforms, Software-Defined WAN (SD-WAN) is a technique that streamlines WAN infrastructures. By moving traffic to less expensive network channels (such as commercial broadband) in place of more expensive leased or MPLS lines, SD-WAN increases the efficiency of data transfer. It is cognizant of the cloud and more easily combines with contemporary cloud infrastructure. One of the WAN technologies that is expanding the fastest is SD-WAN.
Cloud WANs: Becoming popular, allowing businesses to connect to cloud services and resources efficiently. AWS Cloud WAN is a fully managed service for building, managing, and monitoring global WANs.
Ethernet as a WAN Technology (Metro Ethernet/Carrier Ethernet): Ethernet standards have evolved to be viable for WANs over longer distances, with service providers offering Ethernet WAN services.
Wireless WAN (WWAN): WWANs include satellite, public Wi-Fi, and cellular data networks (3G, 4G, LTE, and 5G). VSATs use two-way satellite ground stations.
Digital Subscriber Line (DSL) & Cable Internet: Inexpensive consumer-focused Internet access technologies using existing telephone lines or cable TV cabling.
Packet over SONET/SDH (PoS): A WAN transport communication protocol called Packet over SONET/SDH (PoS) specifies how point-to-point linkages connect via optical fiber and SONET/SDH protocols.
Frame Relay: Data is transmitted between LANs or WAN endpoints using Frame Relay, which packages data in frames and delivers them via a shared Frame Relay network.
Asynchronous Transfer Mode (ATM): Time-division multiplexing is used in the Asynchronous Transfer Mode (ATM) to format data into fixed-sized cells. Early data networks frequently used it, although it has now mostly been replaced.
WAN Protocols:
WANs function based on rules-based principles called protocols.
TCP/IP (Transmission Control Protocol/Internet Protocol): A fundamental protocol suite used to connect Internet and computer network devices. It specifies data packetization, address, transmission, routing, and reception. IPv6 is the newest.
Additional protocols include those listed under connection technologies, including MPLS, ATM, Frame Relay, and PoS.
WAN Optimization: Techniques used to improve WAN performance metrics such as throughput, congestion, and latency.
Traffic Flow Management: By caching, removing duplicate data, and compressing data files, traffic flow management reduces the amount of data transmitted over the network.
Protocol Acceleration: By combining “chatty” protocol communications into fewer packets, protocol acceleration streamlines communication and lowers latency.
Rate and Connection Limits: Limiting users, open internet access lines, and bandwidth per user lets network administrators prioritize commercial applications.
Network Segmentation/Traffic Shaping: Controls data flow for specific applications, prioritizing critical applications and dividing the network into separate zones for better control and security.
Deduplication and Local Caching: Used to counteract performance issues caused by latency and bandwidth constraints.
WAN Security:
Secure WAN data with firewalls, virtual private networks, and other technologies. Users’ homes and other locations are protected by firewalls and antivirus software. VPNs facilitate data encryption and connectivity. A key-exchange feature for device authentication is present in SD-WANs. VPNs do not, however, ensure complete security, and service providers should not be presumed to offer a specific level of protection.
Advantages of Wan Wide Area Network
- Broad covering of geographic area.
- Central administration and infrastructure.
- Security of networks using features like encryption and VPNs.
- Using leased lines to increase bandwidth.
- Travel expense reduction.
- Makes it possible to conduct business globally and connect globally.
- Facilitates distant cooperation and work.
Disadvantages of WAN:
- Expensive setup.
- Potential weaknesses in security and the requirement for firewall and antivirus programs.
- Congestion in the roads can be severe.
- Reduced capacity for fault tolerance.
- Noise and mistakes since there are several points of connection.
- Slower rate of data transfer than LANs because of the great distances.
Popular WAN Use Cases:
WANs are widely used by various organizations globally:
- Government Agencies: To safely exchange time-sensitive, private information.
- Financial Institutions: To connect bank branches and online banking services, ensuring fast and secure real-time transactions.
- Hospitals: For remote treatment plan collaboration, access to electronic health records (EHRs), and sharing private patient data.
- Retail Chains: To enable enhanced analytics for consumer trends and preferences by integrating inventory systems with warehouses.
- Manufacturing: To monitor processes, give real-time supply chain and inventory information, and link factories with corporate activities.