Switching rate rate at which packets can be transferred from input port
to output port of router
Types of switching fabric:
Memory speed limited by memory bandwidth, Bus speed limited
by bus bandwidth, Crossbar
Head-of=the-line blocking queued datagram
The Internet Control Message Protocol (ICMP) is one of the main protocols
of the Internet Protocol Suite. It is used by network devices, like routers, to
send error messages indicating, for example, that a requested service is not
available or that a
1. a) From server B to client A, the source port is 80 and the destination port is
26145.From server B to client C, the source ports are all 80, and the destination
ports are separately 7532 and 26145.
b) For the network-layer datagram, from server to the
a. plaintext : The semester is almost over.
ciphertext: Uac ichciuco si mghkiu ktco.
b. ciphertext: S bmju rmsu!
plaintext: I cant wait!
a. No, without a public-private key pair or a pre-shared secret, Bob cannot verify that
Alice created the messag
Q1.In a system that uses distance vector routing, node A has two neighbors, B and C. They delay from A to B is 4
and the delay from A to C is 6. If it receives the following vector from each of them, fill in its routing table.
A set of protocols allowing
communication across diverse networks
Out of ARPANET
Emphasize on robustness regarding to
Emphasize on Flexibility in operating on
As a result, TCP/IP archit
Client-Server Network Programming in
Client-Server Model (Contd)
Using TCP or UDP
What is Socket
Network Programming in JAVA
Network Programming in JAV
The application layer is where network applications and their application-layer protocols reside. The
Internets application layer includes many protocols, such as the HTTP protocol (which provides for Web
document request and transfer),
Routers and link-layer switches are both packet switches. Similar to end systems, routers and link-layer
switches organize their networking hardware and software into layers. But routers and link-layer switches
do not implement all of
Sockets for server and
Welcomes some initial contact from a client.
Is created at initial contact of client.
New socket that is dedicated to the particular client.
A note on the use of these ppt slides:
Were making these slides freely available to all (faculty, students, readers).
Theyre in PowerPoint form so you see the animations; and can add, modify,
and delete slides (inclu
Meters in kilometer = 1,000
Bits in megabit = 1,000,000
1 millisecond = .001 second
Dial up modems: up to 56 Kbps, bandwidth is dedicated; ADSL: up
to 24 Mbps downstream and 2.5 Mbps upstream, bandwidth is
dedicated; HFC, rates up to 42.8 Mbps and upstrea
1. Yes, BGP allows Z to implement that transition policy. BGP allows AS maintain its path
information to transmit to its neighbors, so in this case, AS Y can show AS X that it
cannot transmit anything to AS Z, then AS Z will not transmit Xs traffic.
1) UDP and TCP use 1s complement for their checksums. Suppose you have the following 3
8-bit bytes. 01011010, 10001000, 11010011. What is the 1s complement of the sum of
these 8-bit bytes?
2) Compute the 1s complement of the sum of
NFS-612 Assignment #2 (Fall 2001)
CHAPTER # 2
Review Question # 9 :
In persistent TCP with pipelining server leaves the TCP connection open after sending the
response. Subsequent requests and responses between the same client and server can be sent over
Chapter 1 Computer Networks and Internet
Propagation Delay and Transmission Delay. Consider two hosts, A and B, connected by a link of
rate R bps. Suppose that the two hosts are separated by m meters, and suppose the propagation speed
Use Dijkstras shortest-path algorithm on the network above to:
1) Compute the shortest path from node t to all nodes.
2) Compute the shortest path from node u to all nodes.
Use the BellmanFord Distance Vector algorithm on the network above to:
1) Compute the shortest path from node t to all nodes.
2) Compute the shortest path from node x to all nodes.
3) Compute the shortest pa
1) Consider distributing a file of F = 20 Gbits to N peers. The server has an upload rate of
us = 25 Mbps, and each peer has a download rate of di = 2 Mbps and an upload rate of uc.
For N = 10, 100, and 1000 and u = 300 Kbps, 500 Kbps and 2 Mbps, prepare
Select the first ICMP Echo Request message sent by your computer, and expand
the Internet Protocol part of the packet in the packet details window. What is the IP address of
a. The IP address of my c
1. Select one packet. From this packet, determine how many fields there are in the
UDP header. (Do not look in the textbook! Answer these questions directly from
what you observe in the packet trace.) Name these fields.
a. Source port, Destination p
a. If five routers are used in this network, then the aggregate throughput among the
thirteen hosts and two servers is 15*150 Mbps = 2250 Mbps.
b. If four hubs are used at the bottom to connect thirteen hosts, then the throughput of
four hubs i
1. a) The end-to-end is N(L/R)
b) The delay with P packets is P*N (L/R)
2. a) The probability of successfully receiving a packet is (1-p)N
b) The average times of transmission is 1/ (1-p) N, then the average times of retransmission is 1/ (1-p) N-1.
1. For obtaining a right IP address from the DNS server, the total time is RTT1+
RTT2+ RTT3+. RTTn, we know that HTTP use TCP protocol, so one RTT0
elapses to set up a connection, and another RTT0 elapses to send request and
receive the object. The total
1. For each interface, the range of destination is showed below:
000 00000-000 11111
001 00000-001 11111
01 000000-01 111111
100 00000-100 11111
101 00000-101 11111
11 000000-11 111111
So the number of address:
Interface 0 = 25 = 32
DL-CS-656, Midterm, Summer 2010
You must e-mail it back by 6.30 PM
For each minute your submission is late, 0.5 points will be deducted from your grade.
For instance, if it is submitted at 6.40 pm, then 5 points will be deducted.
Name and Student ID: