Asad Ijaz
Lead Networking Architect and Editor at NetworkUstad. BS in Computer Networks and Security, CCNP and CCNA certified, with 11+ years of experience in enterprise network design, implementation, and troubleshooting. Writes practical tutorials on routing, IPv4 management, network automation, and security fundamentals.
Cellular Network: How Cellular WAN Technology Works
Cellular networks are a type of wireless WAN technology. They provide connectivity to users and remote locations where no other WAN access technologies are available. Millions of users rely on cellular networks daily to email, browse the web, download apps, stream video, and make voice calls from smartphones, tablets, laptops, and even routers equipped with...
Cable Internet: How It Works, Speeds, and Architecture
Network and Internet access through cable TV is a type of broadband Internet access that uses the existing infrastructure of the television cable system. It provides network edge connectivity from an Internet Service Provider (ISP) to an end user in much the same way DSL and Fiber to the Home (FTTH) do, but riding on...
What Is VSAT? Very Small Aperture Terminal Explained
VSAT stands for Very Small Aperture Terminal. It’s an important WAN technology for both home users and organizations that need connectivity in remote areas where fiber optic, copper cable, and microwave links simply aren’t available. VSAT creates a private WAN using satellite communications, making it one of the few WAN technologies genuinely usable almost anywhere...
What Is MPLS? Multiprotocol Label Switching Explained
MPLS stands for Multiprotocol Label Switching. It’s a wide area network protocol that forwards data from one router to another based on short path labels rather than IP network addresses. The concept originated in 1996 among engineers from Cisco, IBM, and StrataCom, was picked up by an IETF working group in 1997, and was formally...
What Is Ethernet WAN? A Complete CCNA Guide
Ethernet was initially considered unsuitable as a WAN access technology, largely because early Ethernet cabling standards supported only relatively short distances — copper-based Ethernet was historically limited to around 100 meters per segment. Newer Ethernet standards over fiber optic cabling changed that entirely, extending reach far beyond what copper or original Ethernet specifications ever supported....
What Is ATM? Asynchronous Transfer Mode Explained
ATM stands for Asynchronous Transfer Mode. It’s a cell-based networking technology that uses asynchronous time-division multiplexing (also called statistical TDM) to carry voice, video, and data across private and public networks. That “asynchronous” in the name is the key detail: unlike synchronous TDM, which reserves fixed time slots for each source whether or not it...
Leased Lines: What They Are and How They Work
A leased line is a dedicated communication channel between two or more locations. It’s usually a pre-established WAN connection running from a customer’s premises to a service provider’s network, reserved exclusively for that customer’s traffic in exchange for a fixed recurring fee. Because the connection isn’t shared with other subscribers, it delivers guaranteed, consistent bandwidth...
Circuit Switched vs Packet Switched: WAN Technologies Explained
Every wide area network connection relies on one of two switching methods: circuit switching or packet switching. The earlier article on WAN devices covered the hardware routers and modems use to reach a WAN, but that hardware only tells half the story. The switching method chosen by your WAN access technology determines how data actually...
WAN Devices: Roles, Verification, and Selection
A WAN connection rarely involves just a router. Between the customer’s equipment and the provider’s core, a small set of specialized devices each handle a distinct job — converting signals, providing clocking, switching carrier traffic, or forwarding at the speeds a provider backbone demands. Knowing what each device actually does, and how to verify it’s...
Routing Protocol Authentication with MD5: Configuration and Modern Considerations
An unauthenticated routing protocol will accept updates from anything claiming to be a legitimate neighbor, which is exactly the gap an attacker needs to inject false routing information, redirect traffic, or trigger a denial-of-service condition. Authentication closes this gap by requiring routers to prove they possess a shared secret before their updates are trusted, and...