Transcript PPT

Contact Information
Monday & Wednesday: at Tulsa
NH374 (918)594-8473
Office Hours: 1500-1600
 Tuesday, Thursday, & Friday: at
Stillwater
ES303 (405)744-6553
Office Hours: 1500-1600

Exams
Closed Book & Notes
 80-90% on class notes
 10-20% on Required Readings


Start Studying NOW!
Telecommunications

Long Distance Communications via
Electro-Magnetic Means

Long Distance =
Distance > Normal Voice
Conversation
Term Paper
Probe Further
 1,500 - 3,000 words (about 6-12 pages)
 Telecommunications topic of your choice
 Topic MUST be approved by the
instructor

 Submit
5-10 line Outline ASAP
(NLT 13 March 2000)

Due 12 April 2000
Cheating

Don’t do it!

My idol:
Judge Isaac Parker
U.S. Court: Western District of Arkansas
1875-1896
a.k.a. “Hanging Judge Parker”
Required Readings
Download from Web (46%)
 IEEE Articles (50%)
On Tulsa Campus:
Xerox copies from Library
(On reserve at the Check Out Desk)

General Information
Style: Lecture
Most Important Info Written Down
 Available at www.mstm.okstate.edu:
Last Semester’s Power Point Slides
Current Semester’s Power Point Slides
Video Stream of old Lectures
Links to Helpful Sites

Readings
[1] ‘A Word about Network Layouts,
Hubs, and Higher Level Protocols’
 [2] ‘They Keep Going and Going...'

ISO OSI Seven Layer Model
Layer 7
 Layer 6
 Layer 5
 Layer 4
 Layer 3
 Layer 2
 Layer 1
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Application
Presentation
Session
Transport
Network
Data Link
Physical
Word Perfect
Win98 API
TCP, Win98
TCP, Win98
IP, Win98
3Com NIC
3Com NIC
Normalized Propagation Delay

NPD = End-to-End Propagation Delay
Average time to inject a Packet

NPD > 1 implies “High Speed Network”

10 Mbps Ethernet is Slow Speed
IEEE 802.3 Ethernet
Based on late 1970’s technology
 Covers OSI Layers 1 & 2
 10 Mbps Line Speed
 Logical Bus
 Designed to move Computer Data

Types of Traffic...
Computer Data
Bursty
Highly sensitive to errors
Not as time sensitive as voice or video
 Interactive Voice/Video
Fixed Rate (if not compressed)
*Not sensitive to errors
Fixed or Variable Rate (if compressed)
*Sensitive to errors
Time Sensitive

What is CSMA/CD?
 Polite
One
Conversation
node active at a time
No deliberate interuptions
Collisions sometimes occur
after a break
802.3 Back-Off Algorithm

choose random number
1st Collision
0, 1
2nd Collision
0, 1, 2, 3
3rd Collision
0, 1, ..., 6, 7
4th Collision
0, 1, ..., 14, 15
10th Collision
0, 1, ..., 1022, 1023
15th Collision
0, 1, ..., 1022, 1023
16th Collision
Punt
 Wait (Random Number*.0000512) seconds
Major Drawbacks of
CSMA/CD...
MMAT equals infinity
(No guaranteed Bandwidth)
 No Priorities

These make Ethernet the worst LAN
protocol to use for Multimedia Traffic