from the net: Overview of Single-Mode and Multimode Fiber Optics

The article compares single-mode and multimode fiber optic cables, especially in how their core design, light propagation, and use-cases differ. Single-mode fiber has a very small core diameter (8-10 microns) and uses lasers or highly focused light sources so that only one light mode travels through at a time. This greatly reduces signal dispersion, permitting high bandwidth over long distances, with low loss—ideal for telecom backbones, submarine cables, and large-scale data center links. On the other hand, multimode fiber has a larger core (50-62.5 microns), allowing multiple light modes to travel simultaneously. It typically uses LEDs, has more signal dispersion, and is more suited to short-distance links (e.g. within buildings, campuses) because its performance degrades over longer spans.

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The Screws of Doom – A DIY Network Horror Story

 

You know those little plastic wall plugs and microscopic screws that sometimes come bundled with network equipment? Yeah, the ones that look like they were designed for a dollhouse renovation. The moment you open the box, you already know they’re useless. The screws are made of some kind of metallic Play-Doh, and the plugs seem engineered to crumble into confetti the second they touch drywall. But hey, the manufacturer included them, so clearly they’re supposed to be "good enough," right? Spoiler alert: they are not.

I recently tried to humor a client by using a set while mounting a small switch, and it felt less like DIY and more like an exercise in emotional resilience. The plug disintegrated halfway into the wall like a vampire caught in sunlight, while the screw—despite my most delicate screwdriver finesse—instantly stripped itself into a sad, shiny cylinder. At one point, I  considered using my teeth to turn the screw since it seems to be made of cheese. The only thing holding that switch in place was my pride, some lint, blood and a questionable amount of wishful thinking.

In the end, I abandoned the "official" hardware and dug through my stash of real screws, the kind forged from actual metal and not leftover tinfoil from someone’s lunch. The switch is now securely mounted, but I kept the original screws and plugs as a reminder. Not as backup hardware—oh no. They sit in a little jar on my desk, a tiny monument to frustration. Every time I see them, I smile and think: "At least I’m not trying to use those today."

And don't get me started on those patch cables you get with some equipment..

From the net: How WiFi Connection Works

 

WiFi Connection

To understand how WiFi clients connect to a network, we need to familiarize with two key processes. The first one is WPA supplicant, where WPA stands for ‘WiFi Protected Access’. The second one is the DHCP client, in which DHCP stands for ‘Dynamic Host Configuration Protocol’.

To illustrate how wifi connection works, the article will cover the following topics:

• 
  
• Intro to Wi-Fi Networks
• 802.11 Authentication and Association
• The 4-way Handshake Phase
• WPA Supplicant
• Getting a DHCP address via D-O-R-A
• DHCP logs
• Wi-Fi monitoring with NetBeez

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Free webcast: Cybersecurity. Seeing is Securing: Building Network Asset Awareness

 except from Brighttalk registration page ..  Click on the image to register

Cybersecurity. Seeing is Securing: Building Network Asset Awareness

Sep 24 2025, 12:00pm EDT

Duration: 60 mins

Presented by Jennifer Minella - Viszen Security

About this talk

You can’t protect what you can’t see—and in most environments, critical assets are hiding in plain sight. This webinar dives into how network visibility is the foundation for stronger control, smarter security decisions, and better collaboration between NetOps and SecOps. We’ll show you how infrastructure asset awareness plays a key role in Zero Trust, compliance, and incident response—and share real-world tips to reduce blind spots using tools you already have. Whether you’re locking down your environment or just trying to get a handle on what’s out there, this session will help you move from guesswork to clarity. In this webinar, you’ll learn: 1. Why Visibility Comes First How asset awareness underpins Zero Trust, compliance, and incident response. Common visibility gaps in hybrid, multi-vendor, and IoT-heavy environments. 2. Bridging NetOps and SecOps Through Shared Visibility Speaking a common “asset language” to align priorities. Using visibility to reduce friction between operational stability and security posture.............

Blast from the past : The Hewlett Packard HP 1611A (1977): A Digital Logic Analyzer Ahead of Its Time

 

In 1977, Hewlett Packard introduced the HP 1611A, a compact and innovative digital logic analyzer designed for engineers working with the rapidly growing field of microprocessors and digital systems. At a time when computers were shifting from large, room-filling machines to smaller, board-level designs, the HP 1611A gave designers a way to capture, view, and troubleshoot digital signals with speed and precision. With 16 data channels and the ability to trigger on specific logic conditions, it was an essential tool for debugging complex digital circuits that oscilloscopes alone couldn’t handle.

The HP 1611A stood out for its portability and ease of use. Unlike many bulky test instruments of the era, this model was relatively lightweight and featured a front-panel interface with straightforward controls. Engineers could directly connect to circuit boards and observe timing relationships between multiple signals at once. This functionality was critical for diagnosing race conditions, bus conflicts, and other subtle timing issues that were increasingly common in microprocessor-based designs of the late 1970s.

Beyond its technical capabilities, the HP 1611A reflects Hewlett Packard’s reputation for engineering excellence. It represented a bridge between traditional analog test equipment and the emerging need for digital analysis tools. Today, collectors and vintage computing enthusiasts see the 1611A not only as a piece of test gear but also as a historical artifact from the dawn of the personal computing era. Its design highlights how HP anticipated the needs of engineers navigating the digital revolution, making the HP 1611A a landmark instrument in the history of electronics.

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