UTP Cabling

What’s the Difference Between T568A and T568B?

When it comes to wiring RJ45 data jacks and plugs, ANSI, TIA and EIA agree on two wiring standards: T568A and T568B. While these standards are very similar and can oftentimes be chosen according to nothing more than the installer’s preference, there are a few significant differences between the two, and it’s very important to know about these before you begin to build – or expand – your network.

How are T568A and T568B similar?
The main similarity between T568A and T568B is that they both provide wiring schemes for terminating twisted-pair copper network cable (CAT cables) to 8-position RJ45 jacks and connectors. “8 position” refers to the fact that RJ45 data transmission requires 8 conductors, which are provided by the 4 twisted wire pairs found in the copper-based network cable we just mentioned. The pairs in this type of cable are based on four colors (blue, orange, green and brown), with each of pair consisting of solid-colored wire twisted together with another wire that’s of the same color, but striped with white. When untwisted, the 4 pairs result in 8 individual wires: one for each pin of the jack or plug.

What makes them different?
If you look closely at the two wiring diagrams shown above, you’ll see that the only difference (to the eye, at least) between T568A and T568B is that the pin positions for the green and orange pairs have been switched. But aside from the color reversals, there are a couple of compatibility factors that can affect your choice of an RJ45 wiring scheme.

Even though backward compatible with both one-pair and two-pair USOC wiring schemes, T568A has been largely superseded by the more up-to-date T568B. T568B and has become – overall – the most widely chosen wiring schematic because it matches AT&T’s old 258A color code, but at the same time accommodates for current and future needs. In addition, T568B offers backward compatibility with USOC, though for only one pair.

Overclocking

Overclocking Is Easy Now!

Overclocking is the process of increasing the clock frequency of your Central Processing Unit (CPU), Graphical Processing Unit (GPU), Memory, PCI, and/or AGP devices. In other words, making your computer run faster without having to spend the money on upgrades.

Simply put, overclocking your CPU involves running your processor at a faster speed than was intended out of the box. While overclocking, at its core (no pun intended), can be quite simple, there’s a bit more to it than just tweaking one setting. The main setting that determines your CPU speed (known as your Base Clock) also affects your RAM speed, so there’s a bit of tweaking required to get the right balance. You’ll also have to tweak a few voltage levels, because without enough power, the CPU can’t run fast enough. However, higher voltage also means higher temperatures, so you need to be careful not to overheat your CPU, which can lower the life, not to mention fry it completely if you’re not careful.

You’re not truly hardcore until you’ve pushed your hardware beyond the stock speeds defined by the manufacturer.

Clock boosting couldn’t be easier nowadays. AMD and Intel both offer CPUs with fully unlocked multipliers, the holy grail of overclocking. Pushing one’s CPU past its default speed requires little more than turning up the multiplier. That can be done through increasingly user-friendly firmware interfaces and Windows software. Some boards will even overclock themselves—with and without your permission.

There are all kinds of overclockers in the enthusiast community. Some spend ridiculous amounts of time—and money—on elaborate contraptions that chill CPUs using liquid nitrogen. Others plumb their PCs with intricate networks of water-cooling tubing. Those camps tend to seek out the absolute limits of their CPUs. However, most enthusiasts seem content to tap the “free” clock speed headroom that can be exploited with affordable air cooling.

pfSense Tutorial Links

pfSense

pfSense is a free, open source customized distribution of FreeBSD tailored for use as a firewall and router. In addition to being a powerful, flexible firewalling and routing platform, it includes a long list of related features and a package system allowing further expandability without adding bloat and potential security vulnerabilities to the base distribution. pfSense is a popular project with more than 1 million downloads since its inception, and proven in countless installations ranging from small home networks protecting a PC and an Xbox to large corporations, universities and other organizations protecting thousands of network devices.

This project started in 2004 as a fork of the m0n0wall project, but focused towards full PC installations rather than the embedded hardware focus of m0n0wall. pfSense also offers an embedded image for Compact Flash based installations.

pfSense Tutorial Links 

Installing pfSense <click here for link>
Installing pfSense in VMware under Windows <click here for link>
Multi WAN / Load Balancing <click here for link>
PFsense, dual DSL system for only 2k(or less!) <click here for link>
How can I forward ports with pfSense? <click here for link>
Port Forward Troubleshooting <click here for link>

useful guides, credits go to the authors.

PFSense + Lusca-Cache <click here for link>
PFsense+Lusca-Cache with multi-WAN links <click here for link>
Installing vmware-pfsense-dualwan-lusca.docx <click here for link> by mjdy1711xp

cpu power to network speed by juval