Sem1 - Module 7 Ethernet Technologies

This module introduces the specifics of the most important varieties of Ethernet.

802.2 All versions of Ethernet have the same: 1.MAC addressing 2.CSMA/CD 3.Frame format However, other aspects of the MAC sub layer, physical layer, and medium have changed. 10-Mbps and 100-Mbps Ethernet Legacy Ethernet

10BASE# 1.Legacy Ethernet has common architectural features. 2.Networks usually contain multiple types of media. 3.The standard ensures that interoperability is maintained. 4.The overall architectural design is of the utmost importance when implementing a mixed-media network. 5.It becomes easier to violate maximum delay limits as the network grows. 6.The timing limits are based on parameters such as: Cable length and its propagation delay Delay of repeaters Delay of transceivers Interframe gap shrinkage Delays within the station 10BASE2 Coax cable (called Thinnet) flexible, 185meters max, Small flexible cable 10BASE5 Coax cable (called Thicknet) flexible, 500 meters max, larger, heavier cable

10-Mbps Ethernet: Common timing parameters – all 10 Mbps 64 bytes

Common Frame Format 10-Mbps Ethernet:

Not more than five segments. No more than four repeaters may be connected in series between any two distant stations. No more than three populated segments between any two distant stations. 10BASE#: The rule. There may be up to 30 stations on any individual 10BASE2 segment. Out of the five consecutive segments in series between any two distant stations, only three may have stations attached.

10BASE2 Thin Net

10BASE-T wiring and architecture The rule still applies. 10BASE-T links can have unrepeated distances up to 100 m. Hubs can solve the distance issue but will allow collisions to propagate. The 100 m distance starts over at a Hub orSwitch.

10BASE-T Can use following Media: Cat3 Cat5 Cat5e

Signal leaves the NIC and enters the cable on the Orange pair. White-Orange is +ve, solid Orange is negative. Signal leaves the cable and enters the NIC on the SPLIT Green pair. White-Green is +ve, solid Green is negative. 568B 10BASE-T

All versions of Ethernet have the same: 1.MAC addressing 2.CSMA/CD 3.Frame format However, other aspects of the MAC sublayer, physical layer, and medium have changed FastEthernet 10-Mbps and 100-Mbps Ethernet

100-Mbps Ethernet The only difference between Ethernet and Fast Ethernet is the Bit Time The two technologies that have become important are 100BASE-TX, which is a copper UTP medium and 100BASE-FX, which is a multimode optical fiber medium.

The 100-Mbps frame format is the same as the 10-Mbps frame. 1.These higher frequency signals are more susceptible to noise. 2.In response to these issues, two separate encoding steps are used by 100-Mbps Ethernet. 3.The first part of the encoding uses a technique called 4B/5B 4.The second part of the encoding is the actual line encoding specific to copper or fiber. 100-Mbps Ethernet

RJ45 Pinouts are the same as 10BASE-T

Gb Ethernet 1000 – Mbps (1 Gbps) Ethernet

Gb Ethernet Mbps (10 Gbps) Ethernet

Interconnection of different versions of Ethernet To interconnect Ethernet: –10BaseT –100BaseTX –1000BaseT Use an asymmetric Bridge or Switch

Parameters for 10-GPS Ethernet 10 – Gbps Ethernet does not permit half duplex operation, so parameters related to slot timing and collision handling do not apply. The value listed is the official interframe spacing. The interframe Spacing Stretch Ratio applies exclusively 10 10GBase- W definitions

10 Gb Ethernet To summarize, how does 10GbE compare to other varieties of Ethernet? Frame format is the same, allowing interoperability between all varieties of legacy, fast, gigabit, and 10 Gigabit, with no reframing or protocol conversions. Bit time is now 0.1 nanoseconds. All other time variables scale accordingly. Since only full-duplex fiber connections are used, CSMA/CD is not necessary The IEEE sublayers within OSI Layers 1 and 2 are mostly preserved, with a few additions to accommodate 40 km fiber links and interoperability with SONET/SDH technologies. Flexible, efficient, reliable, relatively low cost end-to-end Ethernet networks become possible. TCP/IP can run over LANs, MANs, and WANs with one Layer 2 Transport method. A major conceptual change for Ethernet is emerging with 10GbE. Ethernet is traditionally thought of as a LAN technology, but 10GbE physical layer standards allow both an extension in distance to 40 km over single-mode fiber and compatibility with synchronous optical network (SONET) and synchronous digital hierarchy (SDH) networks. Operation at 40 km distance makes 10GbE a viable MAN technology.