CompE560: Computer Networks
Slides Courtesy: Jennifer Rexford
Principles underlying transport-layer services
Transport-layer protocols in the Internet
Which file is used to detect and build information about the hardware devices
installed on a Windows XP laptop during the boot process?
A technician uses the shrink volume feature of the disk management utilit
Which two operating systems can be upgraded to Windows XP Home? (Choose two.)
Windows 98 SE
Windows NT workstation*
A customer using a Windows XP computer is complaining that a new card reader is not
working. A techn
A freshly installed Windows 7 laptop is plugged into the network and configured with an IP
address. The technician then attempts to ping the laptop from another computer. While the
laptop is able to connect to other devices, the ping requests fail. Wha
What are three pieces of information a level one technician should gather from a customer?
details of any recent changes to the computer*
description of the problem*
output from diagnostic software
output from a remote connection to the cu
A PC is not able to connect to a wired network. Pinging the loopback address is successful,
but the gateway cannot be reached. On the network switch all the interface lights are on,
except for the interface connected to the PC. The LED on the network ca
Which network device makes forwarding decisions based on the destination MAC address
that is contained in the frame?
A customer is considering a multipurpose device to create a home network. Which three
devices are usually
Which two actions should a technician take if illegal content, such as child pornography, is
discovered on the hard drive of a customer computer? (Choose two.)
Contact a first responder.*
Confront the customer immediately.
Shut down the computer until a
Which two rules pertain to the general daily activities of employees in a call center
environment? (Choose two.)
The technician should contact the customer if the technician is going to be late for a followup appointment.*
The technician should adjust t
Which two items common to both Android and iOS devices can be remotely backed up?
Which statement is true about wireless connectivity on an Android mobile device?
If the network SSID is not
A user receives a phone call from a person who claims to represent IT services and then
asks that user for confirmation of username and password for auditing purposes. Which
security threat does this phone call represent?
Which power criterion will affect the number of internal drives that are installed in a
power supply voltage
power supply wattage
A customer needs additional storage space on an older computer. W
Beginning Material - material through the midterm exam
1. What is wrong with the following definition for a C-style symbolic constant
#define PI = 3.24159
a. The actual value of the mathematical constant pi is not 3.24159
b. There should be a s
Here is a listing of C+ language programming questions on Function Objects along with
answers, explanations and/or solutions:
1. What does the function objects implement?
d) none of the mentioned
2. What ar
DNS: Domain Name System
People: many identifiers:
SSN, name, Passport #
Internet hosts, routers:
IP address (32 bit) used for addressing
name, e.g., gaia.cs.umass.edu used
Q: Map between IP addresses
The Channel Allocation
Static Channel Allocation in LANs and
Dynamic Channel Allocation in LANs and
Dynamic Channel Allocation in LANs
2.Single Channel Assumption.
Slide courtesy: Jennifer Rexford
Clients and servers
Socket programming in UNIX
HyperText Transfer Protocol (HTTP)
URL, HTML, and HTTP
What is it?
Dijkstra : Guru of Shortest path Routing
Link State Routing
Bellman Ford : Distance Vector Routing
Analysis of LSR and DVR
Inside a router
Control plane: routing protocols
Data plane: packet forwarding
The lowest layer of the OSI Reference Model is layer
1, the physical layer;
Commonly abbreviated PHY.
The physical layer is special compared to the other
layers of the model, because it is the only one
where data is
Data Link Layer
Data Link Control Protocols
need layer of logic above Physical
to manage exchange of data over a link
control and data
DLC Service Layer
Layers of the Protocol
A network is a combination of hardware and software
that sends data from one location to another.
The hardware consists of the physical equipment that
carries signals from one point in th
Instructor : Dr. Sweta Sarkar
Goals for Todays Class
CompE 560 overview
Goals of the course
Structure of the course
Learning the material
Key concepts in data networking
Assignment : Introduction to Sockets
The Assignment: Create three programs two client programs and one server program. Client 1 will
send a C struct comprising of an integer value, a character value and a float value to the server process.
The server chan
Port triggering has been configured on a wireless router. Port 25 has been defined as the
trigger port and port 113 as an open port. What effect does this have on network traffic?
Any traffic that is using port 25 going out of the internal network will
You want to dispose of a 2.5 terabyte hard drive that contains confidential financial
information. What is the recommended procedure to achieve this?
Use data wiping.
Drill through the HDD.
Smash the platters with a hammer.*
Immerse the HDD in a weak so
After applying a solution to a printer problem, a technician restarts the printer and prints a
test page. Which step of the troubleshooting process is the technician applying?
documenting findings, actions, and outcomes
testing a theory to determine th
What is the preferred method to remove a disc from an optical drive that fails to eject the
Remove the top of the drive enclosure.
Send the drive to an authorized repair depot.
Insert a pin into the small hole on the front of the drive.*
Use a sm
An employee reports that each time a workstation is started it locks up after about 5 minutes
of use. What is the most likely cause of the problem?
The hard disk is failing.
The RAM is malfunctioning.
The CPU experiences overheating.*
The power supply f
Which task should be part of a software maintenance routine?
Check for and secure any loose cables.
Remove dust from the power supply.
Defragment the hard drive.*
Back up the data, reformat the hard drive, and reinstall the data.
What is the purpose o