The Current Ethernet Specifications

Binary to Decimal Chart

Binary value Decimal value 10000000 128 11000000 192 11100000 224 11110000 240 11111000 248 11111100 252 11111110 254 11111111 255

Ethernet over HDMI

HDMI Ethernet Channel technology consolidates video, audio, and data streams into a single HDMI cable, combining the signal quality of HDMI connectivity with the power and flexibility of home entertainment networking.

Half- and Full-Duplex Ethernet

Half duplex uses 2, two wire pairs to send or receive but not both at the same time and if it happens to send at the same time a collision occurs. full duplex uses 4, two wire pairs to send and receive at the same time and has collision prevention. There are no collisions in full-duplex mode. A dedicated switch port is required for each full-duplex host. The host network card and the switch port must be capable of operating in full-duplex mode.

Hex to binary to decimal chart

Hexadecimal Value Binary Value Decimal Value 0 0000 0 1 0001 1 2 0010 2 3 0011 3 4 0100 4 5 0101 5 6 0110 6 7 0111 7 8 1000 8 9 1001 9 A 1010 10 B 1011 11 C 1100 12 D 1101 13 E 1110 14 F 1111 15

Ethernet at the Physical Layer

- Ethernet was first implemented by a group called DIX, which stands for Digital, Intel, and Xerox - They created and implemented the first Ethernet LAN specification, which the IEEE used to create the IEEE 802.3 committee - This was a 10 Mbps network that ran on coax and then eventually twisted-pair and fiber physical media - The IEEE extended the 802.3 committee to three new committees known as 802.3u (Fast Ethernet), 802.3ab (Gigabit Ethernet on category 5) and then finally one more, 802.3ae (10 Gbps over fiber and coax)

802.3 Fast Ethernet and Gig Ethernet Standards

100BaseTX (IEEE 802.3u) - 100BseTX, most commonly known as Fast Ethernet, uses EIA/TIA Category 5 or 5e or 6 and UTP two-pair wiring. It allows for one user per segment up to 100 meters long (328 feet), and uses RJ-45 connector with a physical star topology and a logical bus. NOTE: 100BaseT and 100BaseX: What's the difference? 100BaseT is the name of a group of standards for Fast Ethernet that include 100BaseTX. Also included are 100BaseT4 and 100BaseT2. The same can be said about 1000BaseT and 1000BaseX. 100BaseFX (IEEE 802.3u) - Uses 62.5/125-Micron Multimode fiber cabling up to up to 412 meters long and point-to-point topology. It uses ST and SC connectors, which are media interface connectors. NOTE: Ethernet's implementation over fiber can be referred to as 100BaseTF even though this isn't an actual standard. It just means the Ethernet technologies are being run over fiber cable. 1000BaseCX (802.3z) - Copper twisted-pair called twinax (a balanced coaxial pair) hat can run only up to 25 meters and uses a special 9-pin connector known as High-Speed Serial Data Connector (HSSDC). 1000BaseT (IEEE 802.3ab) Category 5, four-pair UTP wiring, and up to 100 meters long (328 feet). 1000BaseTX - Category 5. two-pair UTP wiring up to 100 meters long (328 feet). Not used, and has been replaced by category 6 cabling. 1000BaseSX (IEEE 802.3z) - The implementation of Gigabit Ethernet runs over multimode fiber-optics cable instead of copper twisted-pair cable and uses short wavelength laser. Multimode fiber (MMF), using 62.5 and 50-mcron core, utilizes an 850 nanometer (nm) laser and can go up to 220 meters with 62.5-micron; 550 meters with 50-micron. 1000BaseLX (IEEE 802.3z) - Single-mode fiber that uses a 9-micron core, 1,300 nm laser and can go from 3km up to 10km. 10GBaseT - 10GBaseT is a standard created by the IEEE 802.3an committee to provide 10Gbps connections over conventional UTP cables (Category 5e, 6, or 7 cables). 10GBaseT allows the conventional RJ-45 used for Ethernet LANs. It can support signal transmission at the full 100-meter distance specified for LAN wiring. If you need to implement a 10Gbps link, this is the most economical way to go. 10GBaseSR - An implementation of 10 Gigabit Ethernet that uses short-wavelength lasers at 850 nm over multimode fiber. It has a maximum transmission distance of between 2 and 300 meters (990 feet), depending on the size and quality of the fiber. 10GBaseLR - An implementation of 10 Gigabit Ethernet that uses long-wavelength lasers at 1,310 nm over single-mode fiber. It also has a maximum transmission distance between 2 meters and 10 km, or 6 miles depending on the size and quality of the fiber. 10GBaseER - An implementation of 10 Gigabit Ethernet running over single-mode fiber that uses extra-long-wavelength lasers at 1,550 nm, It has the longest transmission distances possible of all 10 Gigabit technologies: anywhere from 2 meters up to 40km, again depending on the size and quality of the fiber. 10GBaseSW - 10GBaseSW, as defined by IEEE 802.3ae, is a mode of 10GBaseS for MMF with an 850 nm laser transceiver and a bandwidth of 10Gbps. It can support up to 300 meters of cable length,This media type is designed to connect to SONET equipment 10GBase-LW - 10GBaseLW is a mode of 10GBaseL supporting a link length of up to 10 km on standard single-mode fiber (SMF) (G.652). This media type is also designed to connect to SONET equipment. 10GBaseEW - 10GBaseEW is a mode of 10GBaseE supporting a link length of up to 40 km on SMF based on G.652 using optical-wavelength 1,550 nm, THis is another media type designed to connect to SONET equipment.

EIA/TIA Ethernet Physical Layer Specifications

10Base2 - Known as thinnet and can support up to 30 workstations on a single segment. It used 10Mbps of baseband technology, coax up to 185 meters in length, and a physical and logical bus with Attachment Unit Interface (AUI) connectors. The 10 means 10Mbps, and Base means baseband technology - a signaling method for communication on the network- and the 2 means almost 200 meters. 10Base2 Ethernet cards use BNC (British Naval Connector, Bayonet Neill-Concelman, or Bayonet Nut Connector) and T-connectors to connect to a network. 10Base5 - Known as thicknet, 10Base5 uses a physical and logical bus with AUI connectors, 10Mpbs baseband technology, and coax up to 500 meters in length. You can go up to 2,500 meters with repeaters and 1,024 users for all segments. 10BaseT - This is 10Mbps useing Category 3 UTP wiring. Unlike on 10Base2 and 10Base5 networks, each device must connect into a hub or a switch, and you can have only one host per segment or wire. It uses and RJ-45 connected (8-pin modular connector) with a physical star topology bus.

Broadcast Domain

A broadcast domain is a logical division of a computer network, in which all nodes can reach each other by broadcast at the data link layer. A broadcast domain can be within the same LAN segment or it can be bridged to other LAN segments.

Bit Rates vs. Baud Rates

Bit rate is a measure of the number of data bits (0s and 1s) transmitted in one second in either a digital or analog signal. A figure of 56,000 bits per second (bps) means 56,000 0s or 1s can be transmitted in one second, which we simply refer to as bps. Baud rate was a term of measurement names after a French engineer name Jean-Maurice-Emile Baudot and was mostly used in the 1970s and 1980s. One Baud is one electronic state change per second - for example, from 0.2 volts to 3 volts or from binary 0 to 1. However, since a single state change can involve more than a single bit of data, the bps unit of measurement has replaced it.

Broadband/Baseband

Broadband is what is used at home and in the cellular spectrum as well. It allows multiple signals both analog and digital to share the wire and can do so using FDM (frequency-division multiplexing). Baseband is what all LAN uses. All the bandwidth of the physical media is used by only one signal. If multiple signals are sent from different hosts at the same time you get collisions

CSMA/CD

Carrier Sense Multiple Access/Collision Detection (CSMA/CD) a media access control (MAC L2) method that helps devices share the bandwidth evenly without having two devices transmit at the same time on the network. Transmitting host constantly checks the wire and if another send traffic there a collision occurs and a JAM signal is sent which by the host who has been transmitting causing all hosts to wait a time before trying to send again. If this occurs 15 times the hosts attempting to transmit time out

Binary to Decimal and Hexadecimal Conversion

Each digit used is limited to being either a 1 or a 0, and each digit is called 1 bit. Typically, you count either 4 or 8 bits together, with these being referred to as a nibble and a byte, respectively. Nibble Values: 8 4 2 1 Byte values: 128 64 32 16 8 4 2 1 If a 1 is placed in that decimal value then you add it and any other spot which has a 1 in the bit 0s are not added. If nibble value equals 1111 then it's adding 8 + 4 +2 +1 which sums to max value of 15. If nibble value equals 1010 then it's adding 8 + 2 summing 10. If byte value equals 11111111 then it's adding 128 + 64 + 32 + 16 + 8 +4 + 2 + 1 which sums to max value of 255 If byte value equals 10010110 then it's adding 128 + 16 + 4 + 2 summing 150 If byte value equals 01101100 then it's adding 64 + 32 + 8 + 4 summing 108

AUI vs MII vs GMII

Each of the 802.3 standards defines an AUI, which allows 1-bit-at-a-time transfer to the Physical layer from the Data Link media-access method. This allows the MAC address to remain constant but means the Physical layer can support both existing and new technologies. The original AUI interface was a 15-pin connector, which allowed a transceiver (transmitter/receiver) that provided a 15-pin-twisted-pair conversion. The issue is the AUI interface can't support 100Mbps Ethernet because of the high frequencies involved. Basically 100BaseT needed a new interface, and the 802.3u specifications created one called the Media Independent Interface (MII) that provides 100Mbps throughput. The MII uses a nibble, which is 4 bits. Gigabit Ethernet used Gigabit Media Independent Interface (GMII) and transmits 8bits at a time.

Common Ethernet cable types

Ethernet Name: 10Base5 Cable Type: Coax Maximum Speed: 10Mbps Maximum Transmission Distance: 500 meters per segment. Notes: Also called thicknet, this cable type uses vampire taps to connect devices to cable. Ethernet Name: 10Base2 Cable Type: Coax Maximum Speed: 10Mbps Maximum Transmission Distance: 185 meters per segment. Notes: Also called thinnet, a very popular implementation of Ethernet over coax. Ethernet Name: 10BaseT Cable Type: UTP Maximum Speed: 10Mbps Maximum Transmission Distance: 100 meters per segment. Notes: One of the most popular network cabling schemes. Ethernet Name: 100BaseT Cable Type: UTP, STP Maximum Speed: 100Mbps Maximum Transmission Distance: 100 meters per segment. Notes: Two pairs of Category 5 UTP. Ethernet Name: 10BaseFL Cable Type: Fiber Maximum Speed: 10Mbps Maximum Transmission Distance: Varies (ranges from 500 to 2,000 meters). Notes: Ethernet over fiver optics to the desktop. Ethernet Name: 100BaseFX Cable Type: MMF Maximum Speed: 100Mbps Maximum Transmission Distance: 2,000 meters. Notes: 100Mbps Ethernet over fiber optics. Ethernet Name: 1000BaseT Cable Type: UTP Maximum Speed: 1000Mbps Maximum Transmission Distance: 100 meters. Notes: Four pair of Category 5e or higher. Ethernet Name: 1000BaseTX Cable Type: UTP Maximum Speed: 1000Mbps Maximum Transmission Distance: 100 meters. Notes: Two pair of Category 5e or higher. Ethernet Name: 1000BaseSX Cable Type: MMF Maximum Speed: 1000Mbps Maximum Transmission Distance: 550 meters. Notes: Uses SC fiber connectors. Max length depends on fiber size. Ethernet Name: 1000BaseCX Cable Type: Balanced shielded copper Maximum Speed: 1000Mbps Maximum Transmission Distance: 25 meters. Notes: Uses Uses a special connector, the HSSDC. Ethernet Name: 1000BaseLX Cable Type: MMF and SMF Maximum Speed: 1000Mbps Maximum Transmission Distance: 550 meters multimode/ 2,000 meters single mode. Notes: Uses longer wavelength laser than 1000BaseSX. Uses SC and LC connectors. Ethernet Name: 10GBaseT Cable Type: UTP Maximum Speed: 10Gbps Maximum Transmission Distance: 100 meters. Notes: Connects to the network like a Fast Ethernet link using UTP. Ethernet Name: 10BaseSR Cable Type: MMF Maximum Speed: 10Gbps Maximum Transmission Distance: 300 meters. Notes: 850 nm laser. Max length depends on fiber size and quality. Ethernet Name: 10GbaseLR Cable Type: SMF Maximum Speed: 10Bgps Maximum Transmission Distance: 10 kilometers. Notes: 1,310 nm laser, Max length depends on fiber size and quality. Ethernet Name: 10GBaseER Cable Type: SMF Maximum Speed: 10Gbps Maximum Transmission Distance: 40 kilometers. Notes: 1,550 nm laser. Jax length depends on fiber size and quality. Ethernet Name: 10GBaseSW Cable Type: MMF Maximum Speed: 10Gbps Maximum Transmission Distance: 300 meters. Notes: 850 nm laser transceiver. Ethernet Name: 10GBaseLW Cable Type: SMF Maximum Speed: 10Gbps Maximum Transmission Distance: 10 kilometers. Notes: Typically used with SONET. Ethernet Name: 10GBaseEW Cable Type: SMF Maximum Speed: 10Gbps Maximum Transmission Distance: 40 kilometers. Notes: 1,550 nm optical wavelength. NOTE: An advantage of 100BaseFX over 100BaseTX is longer cable runs, but 100BaseTX is easier to install.

Ethernet addressing

Ethernet addressing works by using the MAC burned in every NIC. The MAC, or hardware, address is a 48-bit (6 byte) address written in a hexadecimal format. The organizationally unique identifier (OUI) is assigned by the Institute of Electrical and Electronics Engineers (IEEE) to an organization. It's composed of 24 bits or 3 bytes. The organization in turn assigns a globally administered address (24 bits or 3 bytes) that is unique to each and every adapter it manufactures. The Individual/Group (I/G) address bit is used to signify if the destination MAC address is a unicast or a multicast/broadcast Layer 2 address. If the bit is set to 0, then it is an Individual MAC address and is a unicast address. If the bit is set to 1, it is a Group address and is a multicast/broadcast address. The next bit is the Local/Global bit (L/G). This bit is used to tell if the MAC address is the burned-in-address (BIA) or MAC address that has been changed locally. The low-order 24 bits of an Ethernet address represent a locally administered or manufacturers-assigned code. This portion commonly starts with 24 0s for the first card made and continues in order until there are 24 1's for the last (16,777,216th) card made. Many manufacturers use these same six hex digits as the last six characters of their serial number on the card.

Ethernet at the Data Link Layer

Ethernet at the Data Link layer is responsible for Ethernet addressing, commonly referred to as hardware addressing or MAC addressing. Ethernet is also responsible for framing packets received from the Network layer and preparing them for transmission on the local network through the Ethernet contention media-access method known as CSMA/CD. Ethernet MAC addresses are made up of hexadecimal addresses.

Ethernet Over Other Standards (IEEE 1905.1-2013)

IEEE 1905 is an IEEE standard that defines convergent digital home network for both wireless and wireline technologies. Some of the technologies include IEEE 802.11 (WiFi), IEEE 1901 (HomePlug, DH-PLC) powerline networking, IEEE 802.3 Ethernet, and Multimedia over Coax (MoCA). The 2905.1-2013 was published in April 2013. The IEEE 1905.1 Standard Working Group is sponsored by the IEEE Power Line Communication Standards Committee (PLCSC). The idea behind the 1905.1 technology standards is simple setup, configuration, and operation of home networking devices using both wired and wireless technologies. This will take advantage of the performance, coverage, and mobility benefits of multiple interfaces (Ethernet, WiFi, Powerline, and MoCA), which enables better coverage and throughput in every room for both wireless and fixed devices.

IPv6 type vs IPv4 type

IPv6 in a network sniffer will show the type as 0x86DD and IPv4 will show 0x0800

Collision Domain

In Ethernet, the network area where data that is being transmitted simultaneously from two or more computers could collide called a collision event. Repeaters and hubs propagate collisions; LAN switches, bridges and routers do not.

Ethernet over Power Line

In February 2011, the IEEE finally published a standard for Baoadband over Power Line (BPL) called IEEE 1901, also referred to as Power Line Communication (PLC), or even Power Line Digital Subscriber Line (PDSL). Although this technology has been available for decades in theory, without an IEEE standard it was just not adopted as an alternative to other high-speed media. Power companies can use this to measure how much power appliances use. In the future BPL will allow you to just plug a computer into a wall power socket and have more the 500 Mbps for up to 1,500 meters.

Ethernet Frame Formats

Preamble: An altering 1,0 pattern that provides a 5MHz clock at the start of each packet, which allows the receiving devices to lock the incoming bit of stream. State of Frame Delimiter (S)F)/Synch: The preamble is seven octets, and the start of a frame (SOF) is one octet (synch). The SOF is 10101011, where the last pair of 1s allows the receiver to come into the alternating 1,0 pattern somewhere in the middle and still synch up and detect the beginning of the data. Destination Address (DA): This transmits a 48-bit value using the least significant bit (LSB) first. The FA is used by receiving stations to determine whether an incoming packet is addressed to a particular host and b=can be an individual address or a broadcast or multicast MAC address. Remember that a broadcast is all 1s (or Fs in hex) and is sent to all devices, but a multicast is sent only to a similar subset of hosts on a network. Source Address (SA): The SA is a 48-bit MAC address used to identify the transmitting device, and it uses the LSB first. Broadcast and multicast address formats are illegal within the SA field. Length or Type: 802.3 uses a Length field, but the Ethernet frame uses a Type field to identity the Ntwork layer protocol. 802.3 by itself cannot identify the upper layer routed protocol and must be used with a proprietary LAN protocol - Internetwork Packet Exchange (IPX), for example. Data: This is a packet sent down to the Data Link layer from the Network layer. The size can vary from 64 to 1500 bytes. Frame Check Sequence (FCS) FCS is a field that is at the end of the frame and is used to store the CRC.

Understanding Hex

Remember that each hex character is one nibble and two hex characters together makes a byte. so hex 6A would be 01101010.

Ethernet Physical Layer Specifications

The Electronic Industries Association and Telecommunications Industry Alliance (EIA/TIA) together form the standards body that creates the Physical layer specifications for Ethernet. The EIA/TIA specifies that Ethernet use a registered jack (RJ) connector on unshielded twisted pair (UTP) cabling (RJ-45). However, the industry is calling this just an 8-pin modular connector. Each Ethernet cable type that is specified by the EIA/TIA has something known inherent attenuation, which is defined as the loss of signal strength as it travels the length of the cable and is measured in decibels (dB). The cabling used in corporate and home markets is measured in categories. A higher-quality cable will have a higher-rated category and lower attenuation. So Cat5 is better than Cat3 because Cat5 has more wire twists per foot and therefore less cross talk. Crosstalk is the unwanted signal interference from adjacent pairs in the cable.

Ethernet Frames

The data Link layer is responsible for combining bits into bytes and bytes into frames. Frames are used at the Data link layer to encapsulate packets handed down from the Network layer for transmission on a type of physical media access. The function of Ethernet stations is to pass data frames between each other using a group of bits known as a MAC frame format. This provides error detection from a cyclic redundancy check (CRC). ERROR DETECTION NOT ERROR CORRECTION.

Sampling Size

When converting to analog, the computer captures a series of samples in specified sizes, which we all call the sampling size. Each data stream sample contains items like dynamic range, frequency content, and more. The measured amplitude level in each sample is quantized by being given a value of the nearest measured increment. A computer will reproduce these values and play then back in the same order and at the same rate at which they were captured, producing a copy of the original waveform. This is called the sample rate or sample size. The number of bits transmitted per second is called the bit rate.

Wavelength

With electromagnetic radiation, radio waves, light waves, or even infrared (heat) waves makes characteristic patterns as they travel through space. Each wave pattern has a certain shape and length. The distance between peaks (high points) is called a wavelength. If two wavelengths are different, we would say they are not on the same wavelength and that is the way we tell different kinds of electromagnetic energy apart.