Midterm Topics

Data transmission
- Compute transmission time given bit rate.
- Compute propagation time given speed of wave in transmission medium.
- Shannon's Theorem on channel capacity.
- Nyquist's sampling theorem
  - Convert signal to noise ratio to and from decibels
- The framing problem
- Definition of Baud rate
- Conversion of analog to digital signals, particularly voice
- Amplitude modulation vs frequency modulation
- Frequency division multiplexing
- Time division multiplexing
Packet transmission
- Encoding bits -- NRZ, NRZI, Manchester, 4B/5B
- Byte stuffing
- 16 bit checksum
- CRC in hardware,
- CRC using polynomials.
  - compute the remainder representing transmission errors with a polynomial
  - Undectected erroros occur only if error polynomial is multiple of generating polynomial
Lans and MAC address issues
- ethernet
- CSMA/CD
- need for minimum packet size.
- efficiency is 1/(1+5a)
- exponential random backoff
- repeaters and bridges in lans
- smart bridges and problem with cycles
- spanning tree algorithm for smart bridges
- multicast and broadcast
- FIDDI and the token ring
- ATM
Distributed software systems
- client server
- static, dynamic and active documents
WAN technologies
- store and forward
- buffering
- addressing hierarchy
- next-hop forwarding
- optimal routing
- Distance Vector (RIP)
- Link state routing (OSPR)
- Connection-oriented vs. connectionless messaging
- ATM circuits
- switching using VPI and ports