Course Philosophy
ECE-CSE 894G: Introduction to Computer Communication Networks I
Ness B. Shroff ECE & CSE [email protected]
ECE & CSE Operation of modern communication networks is very complex Requires the interaction of many systems In the study of netw
Course Philosophy
ECE-CSE 894G: Introduction to Computer Communication Networks I
Ness B. Shroff ECE & CSE [email protected]
ECE & CSE Operation of modern communication networks is very complex Requires the interaction of many systems In the study of netw
Computer Networks
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 2
ECE & CSE
First computer network was the semi-automatic ground environment (SAGE) system developed between 1950 to 1956 for air defense syste
Announcements
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 3
ECE & CSE
All Lectures are on carmen. Please check that you can access them
ECE & CSE
Famous Predictions
Predicting the Next "Great" Networki
Relevant Problems/Network Functionality
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 4
ECE & CSE
Relevant problems (network functionalities) that are to be solved to design networks with high efficiency and
The Internet Protocol
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 5
The Internet Protocol (IP) was developed to provide for the connectionless transfer of packets across an inter-network. In IP, the co
Arrival Process or Counting Process
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 6-9
ECE & CSE
Definition: An arrival process or counting process is that stochastic process cfw_N(t); t 0 such that:
1) 2) 3
Paradox of Residual Life
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 10-14
ECE & CSE
Formally: Let cfw_N(t),t0 be a Poisson Process with rate Let S1, S2,. be successive arrival times, and S0 0 The numbe
Real Network Traffic
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 15-16
ECE & CSE
In actual LAN or WAN type of environments, packet lengths are strongly Bimodal, sometimes Trimodal. Most "sessions" (TCP se
CSE-ECE 861: Homework 1
Due in class by: Wed. Feb. 1, 2012 (1) (4) Solve problems 1.2, 1.5, 1.9, 1.15 from Leon Garcia and Widjija's book (Second Edition). Probability Review Problems (5) (11) (5) Prove that finite additivity follows from countable additi
Derivation of P-K formula
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 15-16
ECE & CSE
Can we use continuous time Markov chain analysis? No, because service time distribution is not exponential Focus on
ARPANET
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 2
ECE & CSE
Packet Switched Network
Concept of store and forward results in more efficient link utilization Why? Statistical multiplexing possible ver
Relevant Problems
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 3
ECE & CSE
Relevant problems (network functionalities) that are to be solved to design networks with high efficiency and good Quality of Servi
Continuous Time Markov Chains
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 9
ECE & CSE
X(t) = Number of packets in the system at time t Is X(t) a counting process? No X(t) is a continuous time stochastic
Birth-death Models
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 11
ECE & CSE
iii.
M-server example: M/M/m system
n =
n ; n = 1,2,.m n = m ; n > m
Poisson()
Exp()
1
2 . . m
ECE & CSE
Birth-death process
Exa
Littles Law
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 12-13
ECE & CSE
L = expected number of packets in the system = arrival rate w = expected waiting time
L= w
Littles Law
ECE & CSE
Littles Law (Proo
Real Network Traffic
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 14
ECE & CSE
In actual LAN or WAN type of environments, packet lengths are strongly Bimodal, sometimes Trimodal. Most sessions (TCP sessions
Paradox of Residual Life
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lecture 11
ECE & CSE
Formally: Let cfw_N(t),t0 be a Poisson Process with rate Let S1, S2, be successive arrival times, and S0 0 The number of
TCP/IP Network Architecture
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 4-5
ECE & CSE
The TCP/IP network architecture is a set of protocols that allow communication across diverse networks These protocols
Arrival Process or Counting Process
ECE-CSE 861: Introduction to Computer Communication Networks
Ness B. Shroff ECE & CSE Lectures 6-7
ECE & CSE
Denition: An arrival process or counting process is that stochastic process cfw_N(t); t 0 such that:
1) 2) 3)
CSE-ECE 861: Homework 2
Due: Wed. Feb. 22, 2012 1. Let cfw_S(t), t 0 be the sum of a random number of independent Poisson processes, each with rate . Is S(t) a Poisson process? Carefully prove or disprove. 2. Use Little's Law to verify PASTA for an M/M/1/