Slides8 - Access Network Design David Tipper Associate...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Access Network Design David Tipper Associate Professor Department of Information Science and Telecommunications University of Pittsburgh Slides 8 http://www.sis.pitt.edu/~dtipper/2110.html • A top down network design project should follow the four steps below: Top Down Network Design Approach – Conceptual Model • Objectives, Requirements, Constraints – Logical Model • Technology, network graph, node location, link size, etc. (where algorithms are used to minimize cost) – Physical Model TELCOM 2110 3 • Specific hardware/software implementations • (e.g., wiring diagram, repeater locations, etc.) – Implementation, Testing, Tuning and Documentation
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Technology Choices Note for Wireless Access Network Design the physical design is incorporated in the Logical Design For Wired Access Network Design the logical layer may be partially separate from the physical design Wired Access Networks Technology Choices Wired Access Networks Technology Choices For circuit switched voice traffic STM, ATM – constant bit rate service (CBR), MPLS CBR emulation For packet data traffic – STM, ATM, SMDS, X.25, Frame Relay, Token Ring, FIDDI, Ethernet, cable modem, dSL, wireless technology, etc. Choice depends on cost and features needed Root 2 1 3 45 TELCOM 2110 4 Given technology selection and logical design – create physical design (select equipment, addressing, wiring, etc) 6 Technology Choices • For Packet Data traffic • Choice depends on distances – Connect Pitt branch campuses and labs (Johnstown, Bradford etc.) to main Pitt campus computer center – – options, Frame Relay, ATM, SMDS, IP/STM, X.25, ISDN, etc. – Connect hosts/servers in different locations of a building to campus backbone • Ethernet, Fast Ethernet, Gigabit Ethernet,Token Ring, FDDI, etc. Need to factor in performance Root TELCOM 2110 5 Need to factor in performance needs and user requirements (e.g., lease vs. buy, security etc.) • Consider LAN physical design 2 1 3 6
Background image of page 2
3 LAN Technology Choices • Choices for LAN equipment Etherne • Ethernet • Token Ring • FDDI • Fast Ethernet • Gigabit Ethernet TELCOM 2110 6 • 802.11 (Wi-Fi), etc. • Majority of installations today are Ethernet to the desktop – growing interest in 802.11 802.11 Classical Ethernet IEEE 802.3 Standard 1983 Bus topology LAN 10 Mbps CSMA/CD medium access control protocol 10Base5 – coax cabling – 10 Mbps – 50-ohm coaxial cable bus – Maximum segment length 500 meters – extend with repeaters 10Base T cabling (1987 TELCOM 2110 7 10Base-T cabling (1987) – Twisted pair, maximum length 100 meters – Star topology (hub at central point)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Ethernet Frame Structure Sending adapter encapsulates IP datagram (or other network layer protocol packet) in Ethernet frame Preamble: TELCOM 2110 8 • 7 bytes with pattern 10101010 followed by one byte with pattern 10101011 • used to synchronize receiver, sender clock rates Ethernet Frame Structure • Addresses: 6 bytes – if adapter receives frame with matching destination address, or with broadcast
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 25

Slides8 - Access Network Design David Tipper Associate...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online