1 / 13

ICSA 745 Transmission Systems Emerged Technologies

ICSA 745 Transmission Systems Emerged Technologies. Nirmala Shenoy Department of Information Technology Rochester Institute of Technology. Emerged Technologies. Scope TI / E1 Carrier Systems X.25 ISDN SS7 FDDI. Emerged Technologies. Coverage Purpose of the technology

jaeger
Download Presentation

ICSA 745 Transmission Systems Emerged Technologies

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. ICSA 745 Transmission SystemsEmerged Technologies Nirmala Shenoy Department of Information Technology Rochester Institute of Technology update 12/15/2001

  2. Emerged Technologies • Scope • TI / E1 Carrier Systems • X.25 • ISDN • SS7 • FDDI update 12/15/2001

  3. Emerged Technologies • Coverage • Purpose of the technology • Typical topology • Layers • PDU • Any other aspects • Conclusions update 12/15/2001

  4. T1/E1 Carriers Systems • Purpose • Up to 1960s telephone networks were analog • 1962 – digital trunks • 1980 – T1 digital carrier lines were introduced • T – telephone carrier line – copper based update 12/15/2001

  5. T1 / E1 Carrier System • Purpose • Initially to carry digitized voice at 64 kbps • Voice was carried as digital signals – DS • DS was primarily based on PCM & ADPCM • Time Division Multiplexing schemes • T1 was the North American Carrier • E1 was the European Carrier update 12/15/2001

  6. T1 / E1 Carrier System • Purpose • T1 – can accommodate 24 64kbps voice channels – bw – 1.544 Mbps • E1 – can accommodate 32 64kbps voice channels – bw – 2.048Mbps • E1 is similar to T1, but not compatible to T1 update 12/15/2001

  7. T1 / E1 Carrier System • Multiplexing hierarchy- T1 • DS0 – one 64kbps channel for one voice user • DS1- 24, 64kbps channels used by T1 • DS2 – 96, 64kbps channels used by T2 • 7DS2 can be multiplexed into DS3 • 6DS3 can be multiplexed into DS4 • T1 uses DS1, but DS1 signals can be transmitted over any carrier. update 12/15/2001

  8. T1 / E1 Carrier System • Topology – similar for T1 and E1 • Typically point to point • Multiple links via cross connect switch update 12/15/2001

  9. T1 / E1 Carrier System • Protocol Layer • Both T1 and E1 are in the Physical layer of the seven layer OSI model • Define connectors, signaling conventions, framing formats, etc update 12/15/2001

  10. T1 / E1 Carrier System • Protocol Data Unit – T1 • Each voice channel gets 8 bits • 24 channels make a frame = 125sec frame • A frame has 192 bits • 193rd bit is a framing bit – synchronization • Synchronization requires 12 bits which are spread over 12 frames update 12/15/2001

  11. T1 / E1 Carrier System • Protocol Data Unit – T1 • Signaling • A & B bit signaling – in band signaling • Done by bit robbing from payload • Off-hook, on-hook, ringing • 8th bit for every 6th and 12th frame • 8th bit is unreliable • 56 kbps update 12/15/2001

  12. T1 / E1 Carrier System • Protocol Data Unit – E1 • Each voice channel gets 8 bits • 32 channels make a frame = 125sec frame • A frame has 256 bits • 32nd byte used for control • Out-of-band signaling update 12/15/2001

  13. T1 / E1 Carrier System • Conclusions • Limited management operations • multiplexing schemes not easy • Bit stuffing problems • Stepping stones to more robust technologies • Sonet/SDH update 12/15/2001

More Related