Final Review
EECS 489 Computer Networks
http://www.eecs.umich.edu/courses/eecs489/w07
Z. Morley Mao
Monday April 16, 2007
Last Class!
Today:
 where have we been?
 where is the networking world going?
 final exam review
Where have we been?
Signaling
telephone network
 ATM
 Internet: RSVP
 hard-state versus soft-state

Where have we been?
Design Principles
separation of control/data (signaling, ftp, http)
 randomization (CSMA-CD, router synch, RED,
SRM, switch scheduling)
 indirection (multicast, mobile IP, SoS, i**3)
 multiplexing: packet level (WFQ, CBQ, priority),
burst level, call level (routing in telephone net)
 virtualization (Internet, RON, IP-over-ATM,
VPN)
 design for scale: hierarchy (hierarchical
routing)

Where have we been?
Routers
address table lookup
 packet classification
 input queue scheduling

Traffic engineering and routing
shortest paths routing
MPLS-based routing
Congestion control and resource allocation
Measurement/management
passive measurements
active measurements
Internet protocol stack
 application: supporting network
applications

FTP, SMTP, HTTP
 transport: host-host data transfer
 TCP, UDP
 network: routing of datagrams from
source to destination

IP, routing protocols
 link: data transfer between
neighboring network elements

PPP, Ethernet
 physical: bits “on the wire”
application
transport
network
link
physical
Where are we headed: a biased view
 network management (incl. measurement)

Networks are becoming increasingly complex
 service management
 application-level networks, overlays
 QoS: not a solved problem end-end
 extensible nets (a.k.a active networking)
 new types of networks:
 sensor nets, body nets, home nets
 security
 ease of use, deployment
Challenge: on beyond the data plane
Q: data plane performance really the major roadblock?
“robustness”
adaptability
“complexity of control” reconfigurability
maintainability
security
evolvability
manageability
the “……ities”
 Fundamental advances here are hard!
“efficiency” not always the most important measure
 little/no past work on the “…ities”
 metrics and models still to be defined

Final exam logistics
 April 19, this Thursday
 1:30-3:30PM
 Closed book, calculator allowed
 Two sheets of notes (both sides)
 Expect roughly the same length as the
practice final
 Material: cumulative

Midterm material included
Final exam topics
 Focus on concepts, understanding and
application of main ideas
 Important topics
Network security
 Basic ideas of network management
 Transport layer
 Multimedia networking
 Wireless networking

• Media access control

Mobile networking
Think at two levels
 Protocols (Details of protocols may change!)
HTTP, SMTP, FTP, DNS, RTP, RTCP, RSVP, SNMP, SIP,
H323, MobileIP
 UDP, TCP, ICMP
 BGP, RIP, OSPF, (link-state, distance-vector, pathvector)
 IP, ARP
 CSMA/CD (CA), MPLS, CDMA, FDMA

 Principles/concepts (fundamental to network design)
 Packet switching, congestion control, flow control,
 Caching/replication, layering (level of indirection),
multiplexing
 Hierarchical structure, signaling, pipelining, error coding
 End to end principle, virtualization, randomization