If you’re trying to set up a new home network, there are two cable choices: Category 5 and Category 6. These are commonly abbreviated as Cat5 and Cat6. So, why are there only these two? And what’s the difference between the two? We’re about to take a close look at Ethernet cable technology, and what separates Cat5 from Cat6. Then, it will be up to you to decide. Let’s get started!
以太网基础知识
如果这是您第一次购买以太网电缆，可能会让您知道有两种类型的电缆。以太网不是相同的吗？事实上，以太网是自20世纪70年代后期以来一直存在的不断变化的标准。然而，它首先在1980年进行了实际应用，并于1983年标准化。回到这些速率，以太网信号在同轴电缆上运行，如电缆线。这些早期以太网电缆的最大转移率为2.94Mbps。这不到较旧的USB 2.0电缆的转移率。然而，现代以太网电缆更快。在非常高端，它们可以转移到40Gbps。但是，这些超快速电缆仅在商业应用中找到。大多数家庭以太网电缆现在提供1Gbps（“千兆”）速度。
Coaxial cable is notorious for rapid signal degradation. This means that the signal will get weaker quickly over long distances. The first step to getting better speeds was to add signal boosters into the network. These signal boosters were called “repeaters,” and allowed for virtually unlimited wire runs. However, early repeaters still had a significant disadvantage. They only had two ports! This was useless for networking, since you could only connect two devices to each-other. Shortly thereafter, repeaters with multiple ports became available. This made it possible to connect multiple devices into a single local network.
In 1987, a company called SynOptics produced the next major advance. Instead of coaxial cable, their new Ethernet cable used a twisted-pair design. Twisted-pair wiring was nothing new. It had been used for telephones for years. The twisted pair of wires reinforced each-others signal, so much longer runs were possible. This stronger signal also reduced the need for shielding, resulting in a slimmer, more lightweight cable. But it wasn’t suitable for the types of speeds people were getting from Ethernet. SynOptics had fixed that problem, and produced a twisted-pair Ethernet cable capable of 10Mbps transfer rates.
Along with this new cabling, SynOptics also introduced hub technology. These hubs were similar to the multi-port repeaters used on coaxial Ethernet. They weren’t required for signal-boosting, but they made it easy to network multiple devices. Later improvements by Motorola and others allowed for more advanced hubs called switches. It’s not a far leap from these switches to the slick无线路由器we use today.
What do Cat5 and Cat6 Mean?
Strictly speaking, Category 5 and Category 6 aren’t only Ethernet cables. They’re also a standard for twisted-wire cable, which, as we mentioned, has been around for a while. The earliest standard, called Category 1, was the standard in residential phone wiring for years. It’s ordinary, thin, landline phone wire with two pairs of twisted wires inside. In the early days of the internet, it was used for home access when necessary. However, it was never used for any sort of serious networking infrastructure. As a result, Category 1 is just a type of twisted-wire cable, not a type of Ethernet.
第2类电缆是一种封蜜的电缆，使用四对电线而不是两对。结果，它可以处理两倍的数据。它从来没有以太网标准。但是，值得一提的是因为它被用于一些未使用以太网的早期网络。它也用于较大的电话网络。但随着较新的，更先进的标准，现在很少使用第2类。
Category 3 cable is the first twisted wire cable standard that’s also a type of Ethernet cable. It’s the cable SynOptics Developed, with the transfer rate of 10Mbps. At the time, this was considered blazing fast, and Cat 3 became the standard from 1987 until the late 90s. However, technology eventually advanced to the point where 10Mbps was no longer fast enough. High-speed internet had arrived, and people needed more speed.
Category 4 is a bit of an oddball. First released in 1996, it used four wire pairs to provide speeds of up to 16Mbps. This was 60 percent faster than Category 3, and seemed like a surefire hit. However, by the time it was starting to catch on, it was already being superseded by Category 5.
What is Cat5e?
第5类电缆于1999年首次发布。然而，大多数人在2001年使用现代变体5类增强型增强型。5类增强电缆，通常称为CAT5E，是3级或4类强大的标准。而不是10类或16Mbps，提供高达1,000Mbps或1Gbps的传输速率。出于这个原因，它通常被称为“千兆”以太网。采用24型电线建造，可支撑长达330英尺的运行，没有开关或助推器。这些较重的电线也允许它提供更高的速度，而无需增加尖端的更多触点。因此，Cat5E电缆与较旧的3类架构兼容。
Needless to say, Cat5e took the technology world by storm, and quickly became the new standard. In fact, many institutional maintenance plans require all old Category 3 cable to be replaced with Cat5e. Cat5e has allowed us to enjoy the modern, high-speed internet we know and love. For instance, it can be used to传输高清视频。Gigabit Ethernet has given us streaming services like Netflix and Hulu, among other major benefits.
什么是cat6a？
第6类（CAT6A）在CAT5E之后几年发布。像Cat5e一样，它使用与3类相同的提示，因此它与旧硬件向后兼容。也喜欢CAT5E，它支持330英尺处的千兆速度。不同之处在于它是一种熔准的电缆，具有显着改善的屏蔽和绝缘。它传统上被用于设施的骨干中的线条，其中很多电缆都捆绑在一起。在这种情况下，更好的屏蔽提供了更好的信号。此外，CAT6A电缆可用于10Gbps速度的较短运行。这在您家中并不有多使用，但对商业应用是必不可少的。
That said, Cat6a can be useful for homeowners and small businesses for one application. Because of its insulated design, it’s better-suited for transmitting power. For many people, that’s not going to do much. But if you want to use a PoE device like a security system, you’ll want to use Cat6a cable. Keep in mind, though, that most routers and switches don’t provide power. To make your system work, you’ll need power injectors andPoE injection adapters。
还有其他选择吗？
Before we conclude, you might be wondering whether there are even more categories of Ethernet cable. In fact, there are two. Category 7 exists, and offers an even better transfer rate than Cat6. That said, it’s only useful for very short runs. For this reasons, it’s used mostly for commercial patch cables. There’s also a Category 8, which is only just starting to get produced. It’s a shielded version of Category 7, which allows for even higher transfer rates. Similar to Category 7, it’s only really used for very short runs in commercial applications. There’s no (current) practical use for these types of Ethernet in your home network.
有什么不同？
As you can see, Ethernet cables have been upgraded several times over the years. Knowing which version is right for you is ideal. Category 3 had an admirable run, but it’s just not suitable for today’s networks. Similarly, Categories 7 and 8 are way more than you’d ever need at home, and too pricey. For 99 percent of people, Cat5e and Cat6a are going to be your best choice.
在速度方面，家庭使用的实际差异很少。如果您居住在一组电源线下，您可能希望使用CAT6A进行添加的屏蔽。但大多数人不会注意到家庭申请中的任何显着差异。对于企业，CAT6A可能更有用。例如，如果您的业务使用更快的千兆位连接，则它可以从调制解调器运行到路由器。此外，它也可以安全地在录音工作室等环境中使用，其中屏蔽至关重要。出于类似的原因，CAT6A在敏感医疗设备上使用更安全。基本上，随着附近的任何时候都有非常敏感的电子产品，CAT6A是个好主意。
Another good reason to use Cat6a is if you have PoE devices around your house. PoE technology has only recently started becoming popular with the general public. However, if you think you might use PoE devices in the future, wire your house with Cat6a. That way, you won’t have to worry about re-wiring the whole house later.
