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Key Networking Concepts: WAN, LAN, SD-WAN, WiFi, Intranet and SSID
As technology underpins communication and functionality for institutions everywhere, deployed networks enabling connectivity continue scaling in complexity. Yet grasping foundational network architecture concepts remains essential even as infrastructure evolves via emerging technologies.
To cut through the jargon and understand conversations around critical networking decisions, let’s demystify ubiquitous terminology you’ll encounter:
What Does WAN mean?
WAN stands for “wide area network”. A WAN refers to an expansive network linking together geographically separate local area networks (LANs) over long distances using public carrier technologies like fibre optic lines and cellular networks spanning across multiple regions or countries.
Contrast this to a LAN centered in a single physical location using technology like Ethernet. WANs connect these dispersed LANs together facilitating communication, access to apps/data and collaboration across distance.
Some key things to know about WANs:
- They connect LANs (Local Area Networks) that are in different locations/cities/countries allowing communication and data access across long distances
- They rely on services by Internet Service Providers rather than user-managed connections
- Common uses of WANs include connecting branch office networks to a central corporate network, connecting data centers separated geographically for redundancy, and facilitating global business communications and file sharing
- Examples of common WAN technologies include MPLS, Frame Relay, ATM networks and X.25. More recently SD-WAN leverages internet to securely connect locations.
- WANs cover much larger footprints than LANs which are contained within a single site. This allows WANs to connect networks spread across states, countries or internationally.
What Does LAN Stand For?
LAN stands for “local area network”. As touched on, LANs denote single-site networks connecting devices mostly over Ethernet and WiFi technologies across a relatively small footprint like an office building, school or home. All connected devices can communicate with each other directly via a LAN.
Some key things to know about LANs:
- A LAN is a computer network that interconnects devices within a limited area such as a home, office building, or college campus. This contrasts with a WAN (Wide Area Network) that spans a larger geography.
- LANs enable connected devices to directly communicate with each other via ethernet cabling or WiFi access points rather than going through the public internet.
- Common network components in a LAN include routers, switches, firewalls, servers, storage arrays as well as endpoint devices like computers, printers, phones.
- Ethernet and WiFi are two major technologies used for communication within LANs across these connected devices.
- Key benefits of LANs include the ability to share resources such as files and devices, exchange internal communications, and access applications like intranet sites and databases locally.
What Does SD-WAN mean?
SD-WAN expands upon traditional WAN architecture. It stands for “software-defined wide area networking”. SD-WAN handles linking LANs across locations like WANs, but leverages software abstraction to power simplified deployment/changes plus policy-based, application-aware traffic routing over public/private infrastructure.
Here are some key things to know about SD-WANs:
- An SD-WAN is a specific type of WAN (Wide Area Network) that connects different locations together over long distances to create one unified network.
- The “software-defined” part refers to the network intelligence being delivered via software to manage network traffic flow based on business policies. This is different from traditional routing which relies solely on hardware.
- Key features of SD-WANs include:
- Simplified deployment and management of WAN infrastructure
- Centralized control across branch locations
- Dynamic traffic steering based on application needs
- Use of less expensive public internet connectivity along with existing MPLS lines
- Benefits compared to traditional WAN architecture:
- Reduced costs by leveraging internet transports
- Flexibility to add/move locations easily
- Visibility into network & application performance
- Intelligent traffic routing optimization
What Does Wireless LAN mean?
Wireless LANs deliver LAN network connectivity over WiFi instead of cabling. Access points provide wireless node connections for devices like laptops, mobile phones, tablets and IoT equipment to connect with each other, access internet, and link with wired LAN infrastructure.
Here are some key things to know about WLANs:
- A WLAN is a wireless network that connects two or more devices using wireless communication within a limited area such as a home, office building, or university campus.
- It is essentially a LAN (Local Area Network) that uses WiFi rather than cables and wired connections to connect devices like laptops, smartphones, printers etc wirelessly.
- The WiFi wireless connection is enabled by WLAN hardware components including wireless access points (WAPs) and wireless network adapters in devices. Access Points transmit and receive the wireless signals to route data.
- The coverage area of a WLAN depends on the number and placement of wireless access points. More access points allow connecting more devices across a wider area.
- Key benefits of deploying a wireless LAN vs a wired network include flexibility, mobility, installation speed and the ability to access the network from anywhere within range.
What Does Intranet Mean?
An intranet refers to a private, controlled internal network ecosystem housed within an organization leveraged for sensitive information/app access and collaboration by employees. Data security, user permissions and functionality differ from what’s externally available to public web users.
Here are some key things to know about intranets in the field of networking:
- An intranet looks and functions like a website but is only accessible by an organization’s employees or individuals with authorized credentials.
- Intranets are used to share information, resources, tools, and applications within a secure, controlled environment. For example, companies use intranets to distribute HR policies, access internal applications, and enable teams to collaborate.
- Intranets are built utilizing internet protocols like TCP/IP but access is limited by firewalls blocking unauthorized external traffic so people outside the organization cannot access sensitive internal data.
- Documents, forums, directories and other assets published on an intranet are not accessible by the public internet like a typical website.
- Common intranet features include document libraries, company directories, knowledge bases, discussion forums, calendars, blogs and dashboards displaying metrics.
What is an SSID?
SSID means “service set identifier”. An SSID is essentially the name broadcasting a particular WiFi network’s existence detectable by devices in range so users can identify and connect to it. So for example network names like “GuestNetwork” or “3rdFloorLobby”.
Here are some key things to know about SSIDs:
- An SSID is a name that identifies a particular Wi-Fi network. It differentiates one wireless network from another.
- For example, when you browse available Wi-Fi networks on your smartphone or laptop, each network will broadcast its own unique SSID name like “GuestNetwork”, “HQ_Floor2”, or “JonesFamilyWiFi”.
- The SSID name of a wireless network is set by the network administrator who configures the Wi-Fi access points.
- When devices like phones scan available wireless signals, they detect the SSID broadcast by an access point to identify the Wi-Fi network it represents and determines whether to connect.
- Wi-Fi protocols require an active SSID broadcast to facilitate automatic connections between client devices and wireless access points.
- Some access points allow disabling SSID broadcasts for simpler network discovery for devices that already know the network name. But in most cases, broadcasting the SSID is preferable.
The Bottom Line
While longstanding network infrastructures and emerging connectivity paradigms continue evolving in complexity, recalling what basic elements like WANs, LANs, SD-WAN, WiFi, intranets and SSIDs fundamentally enable remains centrally useful as:
- Technologies transform
- Strategic architectures shift
- New frameworks emerge
So bookmark this explainer as reference tackling future networking standards you’ll encounter as enterprises adapt next generation architectures aligned to business priorities!