Mujtaba Khattak
Mujtaba Khattak is a network solutions architect specializing in SD-WAN, cloud infrastructure, and network optimization. He holds a BS in Artificial Intelligence from SZABIST, an MBA from Virtual University (VU), and Cisco certifications (CCNA and CCNP). As the founder of NetworkUstad.com, He produce technical guides and tutorials on networking, cybersecurity, and AI applications.
Frame Relay Encapsulation Explained
Frame Relay operates at the Data Link Layer of the OSI model. It takes packets from the layer above, wraps them in a Frame Relay frame, and hands that frame down to the physical layer for delivery. Understanding this encapsulation process is the key to understanding how Frame Relay actually works. The Encapsulation Process The...
Multiple Virtual Circuits: Sharing One Physical Line Across Many Destinations
Frame Relay is a multiplexing technique, and one of its most practically important capabilities is running multiple virtual circuits over a single physical line. A Frame Relay Access Device (FRAD) — typically a router connected to the Frame Relay network — can maintain multiple virtual circuits linking it to different remote endpoints, all through one...
Password Authentication Protocol (PAP): How It Works, Configuration, and Why It’s Insecure
Point-to-Point Protocol (PPP) supports several optional features, and one of the most important is authentication. Authentication lets a router verify the identity of the device on the other end of a link before allowing traffic to pass. By default, PPP authentication is not enabled, but you can turn it on using one of two protocols:...
What Is a Parallel Port? History, Pinout, and How It Works
Parallel ports are typically used for connecting printers, and historically for other peripherals that needed relatively high throughput for their era. The port is also used for interconnection between internal components within some devices. A parallel port transmits multiple bits simultaneously over multiple wires, in contrast to a serial port, which sends one bit at...
Wireless Internet: Wi-Fi, WiMAX, Satellite, and Cellular Explained
Wireless internet uses radio waves instead of physical wires to connect a personal computer, laptop, smartphone, or other device to the Internet. Early wireless technologies lacked the high speed of broadband connections like cable and DSL, but modern wireless technologies have largely closed that gap, and in some cases surpassed it. Wireless Internet Service Providers...
What Is Frame Relay? A Complete CCNA Guide
Frame Relay is a packet-switching telecommunication service designed for interconnecting enterprise LANs over a wide area network. It’s a Layer 2, non-broadcast multi-access (NBMA) WAN technology that allows a single serial interface on a router to connect to multiple remote sites using permanent virtual circuits (PVCs) or, less commonly, switched virtual circuits (SVCs). Though largely...
What Is ISDN? Integrated Services Digital Network Explained
ISDN stands for Integrated Services Digital Network. It’s a circuit-switched technology that uses the local loop of the Public Switched Telephone Network (PSTN) to carry fully digital signals, rather than the analog signals traditional telephone lines were originally designed for. ISDN is a set of communication standards capable of transmitting voice, data, and signaling simultaneously...
What Is Dial-Up? How Dial-Up Modem Connections Work
Dial-up is a WAN connection technique established using a modem and an active PSTN (Public Switched Telephone Network) line. The modem dials a phone number attached to another modem at the destination end and establishes a connection capable of transferring data, using the ordinary analog telephone line as the transmission medium. Dial-up was, for decades,...
What Is PDH? Plesiochronous Digital Hierarchy Explained
It is the abbreviation for Plesiochronous Digital Hierarchy. The term “plesiochronous” comes from two Greek words: plesio, meaning “near,” and chronos, meaning “time.” In a plesiochronous network, the clocks in different network elements run close to the same rate but are not perfectly synchronized, so signal arrival times can drift slightly when multiplexing. It was...
Introduction to WAN Technologies
A LAN connects devices within a single building or campus. The moment you need to connect that LAN to another one across a city, a country, or the globe, you’re in WAN territory — a fundamentally different set of technologies, ownership models, and design trade-offs. Wide Area Networks are what make hybrid work, branch offices,...