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, Mujtaba authors technical guides and tutorials on networking, cybersecurity, and AI applications, with over 160 published posts. He bridges AI innovation with practical networking solutions to empower IT professionals and enthusiasts.
ISDN
ISDN stands for Integrated Services Digital Network. It is a circuit-switched technology using the local loop of a PSTN to carry digital signals. It can transmit both data and voice over a digital line. It is a set of communication standards, which can transmit data, voice, and signalling. ISDN connections provide better speeds and higher...
Dialup
Dialup is a WAN connection technique established using a modem and Active PSTN line. The modem dials a number attached to another computer at the destination end and establishes a connection capable of transferring data. The modem and telephone lines work as a data transfer medium. Usually, a dial-up connection is used as a connectivity...
What is PDH?
PDH is the abbreviation of plesiochronous digital hierarchy. The term plesiochronous derives from two Greek words: ‘plesio’ means ‘near’ and ‘chronos’ means ‘time’. In the plesiochronous digital hierarchy, the clocks are running close but not exactly matched, so signal arrival times may be different when multiplexing, as the transmission rates are directly linked to the...
Introduction to WAN Technologies
Wide-area networks (WANs) are used to connect different LANs together. They can bridge LANs within a city, country, or global region. For CCNA candidates, understanding WANs is crucial for the 200-301 exam’s Network Fundamentals domain (15-25% weightage). CCNP students dive deeper into scalable WAN designs via ENCOR (20-30% on WAN optimization). Here’s why WANs matter:...
Frame Control Field Format – Exclusive Explanation
We have already discussed the frame control field format in the previous lesson that the Frame Control field contains multiple subfields. The figure below illustrates the subfields of the frame control field. Protocol Version – It is a 2-bit field that indicates the current version of the protocol. The receiving devices use this value to...
What is Wireless 802.11 Frame
All Layer 2 frames contain a header, payload, and FCS section. The 802.11 frame format is similar to the Ethernet frame format, with the exception that it contains more fields. The figure below illustrates the wireless 802.11 frame formats and fields. Frame Control – It is 2 bytes long field which determines the type of wireless...
Wireless Deployment Solutions – Exclusive Explanation
Wireless Deployment is depending on the requirement of an organization. Some organizations want coverage for small are while other needed coverage for a large area. Cisco offers deployment both for small and large organizations. Small Wireless Deployment For small wireless deployment requirements, Cisco offers autonomous AP solutions. The different types of autonomous APs are the...
What is Wireless? Exclusive Introduction
Wireless Communication is the fastest-growing and most vibrant technological area in the communication field. It can provide client mobility, the ability to connect from any location and at any time, and the ability to roam while staying connected. It is the technique of transmitting information from one point to another without using any connection like...
Bridge Protocol Data Unit (BPDU) Frame Format: Complete Guide to 802.1D STP (Updated July 2026)
In CCNA labs, spotting a BPDU storm can crash your network—understanding the frame format is your first line of defense.. The spanning tree algorithm exchanges the Bridge Protocol Data Unit (BPDU) to elect the Root Bridge. It is a frame containing 12 different fields with different information. The information in the BPDU is used to...
Master Spanning Tree Path Cost: Conquer Network Loops and Boost Efficiency Today! (Updated 2025)
When a loop occurs in the switched network, the STP uses path cost to resolve the port’s state. Path cost is obtained from the port’s speed. The spanning tree puts the lowest-numbered port into the forwarding state if all connected ports have the same path cost values. For CCNA students, understanding path cost is key...