1 / 16

IST 201

IST 201. Chapter 7. Repeater Classes. Class I Between one Ethernet media and another of the same speed Any unlabeled repeater Class II Daisy-chaining is ok if cable length is less than 5 meters. Repeaters cannot adapt between speeds. Bridges connect Ethernet segments of differing speeds.

audra-ford
Download Presentation

IST 201

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. IST 201 Chapter 7

  2. Repeater Classes • Class I • Between one Ethernet media and another of the same speed • Any unlabeled repeater • Class II • Daisy-chaining is ok if cable length is less than 5 meters. • Repeaters cannot adapt between speeds. • Bridges connect Ethernet segments of differing speeds.

  3. Link Configuration • Autonegotiate – preferable • Manual configuration is ok if autonegotiate fails.

  4. 1000 Mbps Ethernet • 1000BaseT – Twisted pair • 1000Base-SX - short wave laser or LED on multimode • 1000BaseLX – long wave laser on single mode or multimode

  5. 1000-Mbps Parameters • Bit time 1 nanoseconds • Slot time 4096 bit-times • Interframe spacing 96 bits • Collision attempt limit 16 • Collision back-off limit 10 • Collision jam size 32 bits • Max. frame size 1518 octets • Min. frame size 512 bits/64 octets

  6. Frame • Same for all Ethernet.

  7. Transmission • Bits are sent faster • Shorter duration • Require more timing considerations • Pushing bandwidth limits • More susceptible to noise

  8. Encoding • Symbols used for data and controls • Improves transmission of efficiency • Improves synchronization • Improves bandwidth efficiency • Improves SNR characteristics

  9. 1000BaseT Encoding • 8B1Q4

  10. Line Encoding • 4D-PAM5 • Cat5e or better • Uses all 4 wire pairs in full duplex simultaneously • Operates in permanent collision • Send/receive on same pair • Uses sophisticated hybrid circuits • Uses a technique called echo cancellation • Varied voltage levels • Level 1 forward error correction (FEC) • Careful cabling to standard prevents problems with • Noise

  11. Interoperability • Gigabit Ethernet • Fast Ethernet • 10BaseT • Bridge provides transfer from one speed to another • Important for office desktop applications • Wiring closets

  12. Half Duplex – 1000BaseT • Works with CSMA/CD in half-duplex • Not recommended

  13. Timing • Master clocking Mark time for • Slave clocking transmissions • Autonegotiate or manual configured for which device will act in which role. • Usually a multiport device handles the master role when autonegotiate determines.

  14. 1000BaseSX & LX • Fiber • Most recommended for backbones • Group FastEthernet devices • Good noise immunity • No ground problems between floors/buildings • New device options • Excellent distance characteristics • Not susceptible to dc drift (bias) that causes clocking errors (same digit represented sequentially) • Not usually used for office desktop connections • Copper 10/100/1000 network interfaces are common • Copper is more “user proof”

  15. Encoding • 8B/10B

  16. Line Encoding • NRZ – level driven not edge driven

More Related