1. © ITT Educational Services, Inc. All rights reserved. IS3120 Network Communications Infrastructure Unit 2 IEEE 802.3 CSMA/CD and the Evolution of Ethernet Networking

2. © ITT Educational Services, Inc. All rights reserved.Page 2 IS3120 Network Communications Infrastructure Class Agenda 3/25/16  Learning Objectives  Lesson Presentation and Discussions.  Discussion on Assignments.  Discussion on Lab Activities.  Break Times as per School Regulations.  Quiz 1-Open book- Chapter 1 and 2

3. © ITT Educational Services, Inc. All rights reserved.Page 3 IS3120 Network Communications Infrastructure Learning Objective  Differentiate between the Ethernet standards, specifications, and technologies that drive current LAN connectivity.

4. © ITT Educational Services, Inc. All rights reserved.Page 4 IS3120 Network Communications Infrastructure Key Concepts  IEEE 802.3 CSMA/CD family of standards and specifications  IEEE 802.3 CSMA/CD versus Ethernet v2 frame formats  Data Link layer versus MAC layer 10/100/1000/10000 Ethernet networking  Single versus multiple broadcast domains

5. © ITT Educational Services, Inc. All rights reserved.Page 5 IS3120 Network Communications Infrastructure Network and Networking.  Network is connecting network devices for the purpose of communicating  Networking is to ensure that the devices on the network are actually communication.  Network is simple but networking is not simple.  Why?  Students should explore.

6. © ITT Educational Services, Inc. All rights reserved.Page 6 IS3120 Network Communications Infrastructure Network component  There are different type of component on the network.  A computer  A printer  A scanner  A server  A Webserver  A local area network(LAN)switch  A router  Each of them with unique identification

7. © ITT Educational Services, Inc. All rights reserved.Page 7 IS3120 Network Communications Infrastructure Ethernet  Ethernet was originally developed by Xerox in the early 1970s  Most common LAN technology  Data is transmitted in packets called frames  Standards include Access and use Physical hardware

8. © ITT Educational Services, Inc. All rights reserved.Page 8 IS3120 Network Communications Infrastructure Access Method: CSMA/CD Listen before transmission Wait to transmit Carrier Sense More than one device can access the medium Multiple Access Detects simultaneous transmissions Each node waits before retransmission Collision Detection Carrier Sense Multiple Access with Collision Detection

9. © ITT Educational Services, Inc. All rights reserved.Page 9 IS3120 Network Communications Infrastructure Ethernet Physical Layer Specifications  Deconstructing media type names [speed]Base[medium]  Speed is megabits per second (Mbit/s)  Medium describes the type of cabling or other transmission media  Example: 10Base-T = 10Mbit/s over twisted pair

10. © ITT Educational Services, Inc. All rights reserved.Page 10 IS3120 Network Communications Infrastructure Specifications: Early  Speed: 10 Mbit/s  Mostly obsolete  Adopted 1983-1993 StandardMedia TypeDescription 802.310Base5Thick Coaxial 802.3a10Base2Think Coaxial 802.3i10Base-TTwisted Pair 802.3j10Base-FFiber Optic

11. © ITT Educational Services, Inc. All rights reserved.Page 11 IS3120 Network Communications Infrastructure Specifications: Fast Ethernet  Speed: 100 Mbit/s  Adopted 1995-1998  Still widely in use *Collectively referred to as 100Base-T StandardMedia TypeDescription 802.3u100Base-TX*, 100Base-T4*Twisted Pair 802.3u100Base-FX, 100Base-SX, 100Base-BX Fiber Optic 802.3y100Base-T2*Twisted Pair

12. © ITT Educational Services, Inc. All rights reserved.Page 12 IS3120 Network Communications Infrastructure Specifications: Gigabit Ethernet  Speed: 1000 Mbit/s (1 Gbit/s) or 10 Gbit/s  Adopted 1998-Current StandardMedia TypeDescription 802.3z1000Base-XFiber Optic 802.3ab1000Base-TTwisted Pair 802.3ae10GBase-SR,-LR, -ER,-SW,-LW, -EW Fiber Optic 802.an10GBase-TTwisted Pair 802.3aq10GBase-LRMMultimode Fiber

13. © ITT Educational Services, Inc. All rights reserved.Page 13 IS3120 Network Communications Infrastructure Network Topology  The layout of how devices connect to a network is the network topology  Some of topologies:  Bus, Star, Extended Star, Ring, Mesh, Hybrid, Hierarchical, Point-to-Point

14. © ITT Educational Services, Inc. All rights reserved.Page 14 IS3120 Network Communications Infrastructure Basic Wired Ethernet Topologies  Bus: All nodes are on the same wire 10Base5, 10Base2  Star: Nodes are wired to a central connection point 10Base-T, Fast Ethernet, GigE  Hierarchical: Connected star networks

15. © ITT Educational Services, Inc. All rights reserved.Page 15 IS3120 Network Communications Infrastructure Ethernet Frames  Ethernet-specific data packet  Besides data, contains elements required for routing to the proper endpoint and port  Most commonly used frames Ethernet v2 (Ethernet II) 802.3 (CSMA/CD) Ethernet IEEE 802.3 Standard Reference: http://standards.ieee.org/about/get/802/802.3.html

16. © ITT Educational Services, Inc. All rights reserved.Page 16 IS3120 Network Communications Infrastructure Common Ethernet Frame Fields Identifies frame and sync signal Preamble MAC address of destination node Destination Address MAC address of source node Source Address Payload data Information CRC for error detection Frame Check Sequence (FCS)

17. © ITT Educational Services, Inc. All rights reserved.Page 17 IS3120 Network Communications Infrastructure EXPLORE: PROCESSES

18. © ITT Educational Services, Inc. All rights reserved.Page 18 IS3120 Network Communications Infrastructure Internetworking  Internetworking is a term used to describe connecting LANs together  Internetworking Devices  Bridge-at layer 2  Router-at layer 3-support many networks  Layer 3 switch-A switch with bridge and router software.  Gateway- can be a computer with routing software a router.

19. © ITT Educational Services, Inc. All rights reserved.Page 19 IS3120 Network Communications Infrastructure Internetworking with Router  A router is a device that operates at the Network Layer  Routers can make intelligent decisions on where to send packets base on a routing table  Routers are very powerful network devices.  Router have redundant processors and plenty of memory, and can support lots of network connections

20. © ITT Educational Services, Inc. All rights reserved.Page 20 IS3120 Network Communications Infrastructure Type of Network  A circuit-switched network- plain old telephone service (POTS) or Public Switched Telephone Network (PSTN), carried analog signals.  Packet-switched network-transmit packets as individual messages to intended destination.  Storage Attached Network (SAN)- is a high-speed network of storage devices that also connects those storage devices with servers  ALOHA network-Additive Links On-line Hawaii Area was build in 1971-random-access protocol

21. © ITT Educational Services, Inc. All rights reserved.Page 21 IS3120 Network Communications Infrastructure Working with Broadcast Domains Broadcast frames are sent to all devices on a network Devices that receive the same frames are in the same domain Switches and bridges pass broadcast frames to all devices Therefore, all attached devices are a single broadcast domain

22. © ITT Educational Services, Inc. All rights reserved.Page 22 IS3120 Network Communications Infrastructure Single Broadcast Domain with Switch

23. © ITT Educational Services, Inc. All rights reserved.Page 23 IS3120 Network Communications Infrastructure Multiple Broadcast Domains with Router  Routers can segment network  Each segment has its own broadcast domain

24. © ITT Educational Services, Inc. All rights reserved.Page 24 IS3120 Network Communications Infrastructure Multiple Broadcast Domains with VLANs  VLAN: Virtual LAN  Collection of ports on one or more switches configured into a single broadcast domain  Layer 3 device (e.g., router) is required to communicate between VLANs  Allows segmenting by business functional or security needs

25. © ITT Educational Services, Inc. All rights reserved.Page 25 IS3120 Network Communications Infrastructure Multiple Broadcast Domains with VLAN

26. © ITT Educational Services, Inc. All rights reserved.Page 26 IS3120 Network Communications Infrastructure Discussion Topics  What are the disadvantages of having many nodes in a single broadcast domain?  What are the advantages of creating multiple broadcast domains with VLANs instead of with routers?  How does segmentation of a large network using VLAN improve data security?

27. © ITT Educational Services, Inc. All rights reserved.Page 27 IS3120 Network Communications Infrastructure Role of CSMA/CD in Ethernet  CSMA/CD forces computers to listen to traffic on the Ethernet segment before sending  This makes sure that no other host on the wire is sending  Mitigates signal collision so that the transport media is not rendered unusable

28. © ITT Educational Services, Inc. All rights reserved.Page 28 IS3120 Network Communications Infrastructure Seven Domains of a Typical IT Infrastructure

29. © ITT Educational Services, Inc. All rights reserved.Page 29 IS3120 Network Communications Infrastructure IP Addressing Domains DomainUse(s) LANCSMA/CD networking and the Ethernet standard are commonly found in local- area-network solutions. Although legacy ring and serial networking solutions can still be found, Ethernet has become the de facto standard in many networks. LAN-to- WAN CSMA/CD networking and the Ethernet standard often provide the “last mile” interconnection between LAN and WAN network segments and may be used for MAN-level networking even on the network backbone between LAN segments.

30. © ITT Educational Services, Inc. All rights reserved.Page 30 IS3120 Network Communications Infrastructure Rationale  CSMA/CD protocols provide a more extensible network environment by allowing multiple computers to transmit data simultaneously on switched networks without requiring token- passing or deterministic enrollment for transmission control.  The Ethernet standard is found in many networks, from large extended enterprise environments to SOHO and home-scale.

31. © ITT Educational Services, Inc. All rights reserved.Page 31 IS3120 Network Communications Infrastructure Summary  In this presentation, the following were covered: Ethernet LAN Standards (IEEE 802.3) Carrier sense multiple access with Collision Detection (CSMA/CD) 802.3 Physical Specifications Comparison of Ethernet v2 and 802.3 (CSMA/CD) frames Working with broadcast domains

32. © ITT Educational Services, Inc. All rights reserved.Page 32 IS3120 Network Communications Infrastructure Assignments and Lab Activities.  Quiz 2.1 Quiz  Lab 2.2 IEEE 802.3 CSMA/CD & Ethernet II Networking  Lab is online on VLab  Assignment 2.3 Evolution of Ethernet  Read chapter 5 for next week class.