Ethernet is a widely deployed technology and is a reference in the networking world. It has many associated standards depending on the type of media used (i.e., copper, fiber, or wireless) and speed (10Mbps, 100Mbps, 1Gbps, or 10Gbps). Older Ethernet standards were based on coaxial cable, but this is not the case in modern networks. The most important Ethernet standards are as follows:
- 10BaseT
- 100BaseT
- 1000BaseT
- 100BaseTX
- 100BaseFX
- 1000BaseX
- 10GBaseSR
- 10GBaseLR
- 10GBaseER
- 10GBaseSW
- 10GBaseLW
- 10GBaseEW
- 10GBaseT
You can see a pattern when looking of these standards’ naming convention. The first part defines the maximum speed at which the standard operates, as follows:
- 10 = 10Mbps
- 100 = 100Mbps
- 1000 = 1Gbps
- 10G = 10Gbps
“Base” stands for baseband, which means the cables use a single frequency to send the data from one end to the other. As opposed to baseband technology, Broadband technology uses many frequencies to send data, as it operates over a shared medium (e.g., TV cables). The last part of the naming convention defines the type of media used by the standard, which can be copper (T comes from twisted-pair) or fiber optics (the other abbreviations).
10BaseT
10BaseT is one of the earlier twisted-pair standards of Ethernet and it offers a maximum bandwidth of 10Mbps. The T represents twisted-pair (i.e., it’s a copper-based standard). This standard uses only two pairs out of the four available on a standard UTP cable (one pair for Transmit and another for Receive). When 10BaseT was first introduced, the standard cable used was a Category 3 cable that operated at a maximum distance of 100 m.
100BaseT
As 10Mbps was not enough for network users’ growing needs, the 100BaseT standard was developed, also known as FastEthernet. The higher speeds of 100BaseT also involve higher requirements from a cable perspective. This standard uses a Category 5 or higher twisted-pair copper cable and it operates at a maximum distance of 100 m. This standard also uses only two pairs out of the four available on a standard UTP cable (one pair for Transmit and another for Receive).
100BaseFX
100BaseFX is the equivalent of 100BaseT, with the only difference being that it operates over fiber links instead of copper cables. Pairs of optical fibers are used, one of them for Transmit purposes and the other for Receive purposes, thus achieving a full-duplex functionality. Two types of fiber links support this standard:
- Multi-mode fiber: operates at a maximum distance of 400 m (half-duplex) or 2 km (full-duplex)
- Single-mode fiber: operates at distances greater than 2 km
1000BaseT
The next natural step was the increase from 100Mbps to 1Gbps, thus the 1000BaseT standard. This also operates over Category 5 cable but is usually used with Cat 5e or Cat 6 cables. Unlike the 100BaseT standard, 1000BaseT uses all four network pairs in the UTP cable.
1000BaseX
1000BaseX is the fiber optic correspondent of 1000BaseT and it comes in many variations, depending on the type of fiber used:
- 1000BaseSX: short wavelength laser (up to 550 m)
- 1000BaseLX: long wavelength laser (over 5 km)
10GBase Standards
The most important 10Gbps standards used in data center networking are:
- 10GBaseSR
- 10GBaseLR
- 10GBaseER
The 10GBaseSR (Short Range) standard operates using short-range communication. It initially operated up to 80 m but, using proper multi-mode fiber, it can go up to 300 m. It is generally used inside a single room or inside a single data center.
10GBaseLR (Long Range) operates over longer ranges and for this reason it uses single-mode fiber instead of multi-mode fiber. This standard usually operates up to 25 km and uses lasers to ensure that a high-power light signal can travel over such a long distance.
10GBaseER (Extended Range) operates over even greater distances using single-mode fiber. It can travel up to 40 km.
10G over WAN
Service providers might utilize the following 10G Ethernet standards that operate over WAN:
- 10GBaseSW
- 10GBaseLW
- 10GBaseEW
These standards correspond to the 10GBaseSR/LR/ER standards (which are usually used within an enterprise data center) and they use a short, long, and extended range of operation. This integrates a 10Gbps Ethernet connection with a SONET/SDH WAN using the same types of fibers and connectors and it operates over the same distances as the SR/LR/ER standards.
10GBaseT
10GBaseT is a special standard that allows 10Gbps transmission over copper cables (twisted-pair) in situations in which you may not want to use optical fibers. This standard uses the following media types:
- Category 6 cable: operates up to 55 m
- Category 6a cable: operates up to 100 m