Computer Science & Software Engineering
CSCI 466
Networks
Fall 2011
Midterm Information
Exam rules:
Friday, December 16th, 3-5pm
Closed book, closed notes, no electronic devices except for a calculator.
You are allowed a two-sided 8 1/2 x 11 note sheet, hand-written
No makeups will be considered without an official University excuse
Material covered:
Lectures 0-22
Computer Networks: 1.1-1.6, 2.1-2.7, 3.1-3.3, 4.1, 4.4, 5.1-5.5, 6.1-6.6, 9.1, 9.3, 9.4
Detailed topics:
Protocol stacks, encapsulation
7-layer OSI model
Internet architecture, TCP/IP model
Measuring performance: bandwidth, throughput, latency, RTT, jitter, delay x bandwidth
Physical ways to transmit bits: cables, wireless, microwave, satellite
Link capacity, Shannon-Hartley Theorem
Encoding bits: NRZ, Manchester, NRZI, 4B/5B
Framing data: sentinel-based, count-based, clock-based
Error detection/correction, checksums, CRCs
Building blocks for reliable transmission: acknowledgements, timeouts
ARQ algorithms: stop-and-wait, sliding window
Ethernet MAC addresses, how they are assigned
Progression of Ethernet technologies, why so successful
Media Access Control for shared Ethernet
Difference between shared and switched Ethernet
802.11 wireless, collision avoidance, ACKs
Wireless, base station versus ad hoc/mesh networks
Wireless, hidden node problem, exposed node problem
Difference between a router, switch/bridge, repeater, hub
Types of switching: datagram and virtual circuit, advantages/disadvantages
Backward learning in switches
Flooding in switching, problem with loops, spanning bridge algorithm
Virtual LAN (VLAN)
Internet protocol, service model
IPv4 packets, how fragmentation works
IPv4 addresses, classful addresses, subnetting, CIDR, private IPs
Address resolution protocol (ARP)
Host configuration using DHCP
Error reporting (ICMP): traceroute, path MTU discovery
Routing protocols: link-state, distance-vector, path-vector. How they work, where they are used, advantages/disadvantages.
Dijkstra's algorithm for finding shortest path
Representation of network as a graph
Routing areas for scaling inside an AS
Intradomain versus interdomain routing
Autonomous systems, what they are, different kinds, peering
Border Gateway Protocol (BGP), routing inside/outside an AS, prefix hijacking
IPv4 versus IPv6
Network Address Translation (NAT), problems with NAT
UDP hole punching
Techniques which mitigate running out of IPv4 addresses
Goals and features of IPv6
Unicast, multicast, broadcast, anycast
Mobile routing
Transport layer: issues addressed, how it provides process-to-process communication
Port number abstraction, how clients find port number
UDP protocol: header, demux key, advantages/disadvantages
UDP apps: simple query, request/reply (RPC), multimedia (RTP)
TCP protocol: header, demux key, advantages/disadvantages
TCP sequence numbers, flow control, 3-way handshake, common extensions, sliding window
TCP silly window syndrome, Nagle's algorithm, Clark's algorithm
TCP timeouts, adaptive timeouts
Router queuing disciples: FIFO, priority, fair queuing
Router drop policies: tail drop, random early detection (RED)
Congestion collapse, control versus avoidance
Additive increase, multiplicative decrease (AIMD)
TCP congestion control: basic, slow start, fast retransmission, fast recovery
Explicit congestion notification, source-based avoidance
Quality of service, type of applications
Integrated services (IntServ): RSVP, leaky/token bucket
Differentiated services (DiffServ): expedited forwarding, assured forwarding
Domain Name System (DNS): namespace, DNS protocol, name resolution process, caching
Web: URLs, HTML, HTTP
HTTP protocol: request methods, headers, 1.0 vs 1.1
HTTP performance: conditional requests, caching, content distribution networks
Email format: RFC 822, MIME, base64 encoding, addresses
Email protocols: SMTP, POP, IMAP
Overlay networks: what they are, uses such as IPv6, VPN, Mobile IP, multicast, RON
Peer-to-Peer (P2P): centralized, pure, hybrid
Peer-to-Peer (P2P): query flooding (Gnutella), how BitTorrent works
Page last updated: August 16, 2012