Midterm Review 1 Introduction –Basic terminology and concepts. Physical Layer –Time and frequency domains. –Bandwidth and data rate. –Analog and digital transmission. –Simplex, half-duplex and full-duplex transmission.

Midterm Review 2 Physical Layer (cont’d) –Transmission impairments. –Decibel. –S/N ratio. –Channel capacity. Nyquist. Shannon. –Types / properties / advantages / disadvantages of media Copper (UTP: Cat-3, Cat-5) Fiber.

Midterm Review 3 Physical Layer (cont’d) –Data encoding Analog-to-digital. –(Time sampling / amplitude quantization) Digital-to-analog. –(Data reconstruction) –Transmission modes. Synchronous. Asynchronous.

Midterm Review 4 Data Link Layer (Error & Flow Control) –Framing –Error detection / correction schemes. –Parity. –Hamming distance –CRC (polynomial encoding) Flow control.

Midterm Review 5 –Flow Control –Acknowledgement –Stop and Wait –PAR / ARQ –Sliding Window –Piggybacking –“go back n” –Pipelining –Selective repeat

Bit Length of a Link Assume link is fully occupied 1 st bit is just arriving at the receiver sender has sent continuously R = data rate (bps) d = distance (length of link) (meters) V = propagation velocity (meters / second) (~ x 10 8 meters/second) Bit length = Rd / V bits

Midterm Review 6 –DLL / MAC protocols Static Dynamic –Multiplexing. Frequency-Division Multiplexing (FDM). Time-Division Multiplexing (TDM). Statistical Time-Division Multiplexing (STDM).

Midterm Review 7 LANs –Protocol architecture. –Ethernet (802.3) design parameters (length, frame size) standards / reasons –Frame format (not details) –LAN topologies.

Midterm Review 8 MAC –Centralized and distributed control. –Synchronous and asynchronous. –Asynchronous MAC. Round-robin, reservation, and contention. LLC for LANs.

Midterm Review 9 MAC protocols. –Contention. ALOHA and Slotted ALOHA. CSMA. CSMA/CD. –Token Passing Token bus. Token ring.

Midterm Review 10 Ethernet –Cabling –Manchester encoding –Backoff –Switched –Performance / speed / length High-Speed LANs –FDDI –Fast Ethernet –Gigabit Ethernet

Midterm Review 11 Wireless LANs –Hidden station problem –MACA / MACAW –RTS / CTS –Frames / Fragments

Midterm Review 12 LAN interconnection –Interconnection schemes and devices. –Bridges –VLAN Routing with bridges / transparent bridges –Fixed routing. –Spanning tree –Source routing –Route discovery –Address learning –Backward learning

Encapsulation Application data header TCP IP LLC MAC trailer TCP segment IP datagram LLC PDU MAC frame

Summary Channel allocation methods and systems for a common channel. X X X