Business Data Communications Final
Exam
What are the layers of the Internet model (correct numbering and order)? - ANS-5) Application
Layer
4) Transport Layer
3) Network Layer
2) Data Link Layer
1) Physical Layer
Provide examples of protocols used at layers 2 thru 5 of the internet model: - ANS-5)
Application Layer - HTTP (Hypertext Transfer Protocol)
4) Transport Layer - TCP (Transmission Control Protocol
3) Network Layer - IP (Internet Protocol)
2) Data Link Layer - Ethernet
What are the layers of the OSI model?
How does it differ from the Internet model? - ANS-7) Application Layer
6) Presentation Layer
5) Session Layer
4) Transport Layer
3) Network Layer
2) Data Link Layer
1) Physical Layer
Internet model combines layers 5-7 into Application Layer
What is an application architecture? - ANS-Application architecture is the way in which the
functions of the application layer software are spread among the clients and servers in the
network.
What are the four functions of an application program?
What does each function do? - ANS-1) Data storage - holds data for storage or retrieval
2) Data access logic - the processing required to access data
, 3) Application logic - what the app does
4) Presentation logic - the presentation of information to the user and the acceptance of the
user's commands.
How are the application program functions spread across devices in 2-tier and 3-tier
architectures? - ANS-2-tier:
Server >> data
Client >> application & presentation logic
3-tier:
Application server: application logic
Database server: data access & data storage
Client: presentation logic
What is a thin client? - ANS-Places little or no application logic on the client.
(If an application changes, only the server needs to be updated.)
What are the two different types of data seen in communications networks? - ANS-1) Digital -
binary
2) Analog - wave-like
What is the definition of a multi-point circuit?
A dedicated circuit? - ANS-Multi-point >> shared circuit
Dedicated >> One device directly connected to another device
What are half-duplex, full-duplex, and simplex transmissions? - ANS-Half-duplex >> 2-way
transmission only one direction at a time (walkie-talkie)
Full-duplex >> transmit both directions simultaneously with no turnaround time (phone call)
Simplex >> one-way transmission (radio, tv)
What is a multiplexor? - ANS-A device allowing one or more low-speed analog or digital input
signals to be selected, combined and transmitted at a higher speed on a single shared medium
or within a single shared device.
What is multiplexing? - ANS-To break one high-speed physical communication circuit into
several lower-speed logical circuits so that many different devices can simultaneously use it but
still "think" that they have their own separate circuits.
Exam
What are the layers of the Internet model (correct numbering and order)? - ANS-5) Application
Layer
4) Transport Layer
3) Network Layer
2) Data Link Layer
1) Physical Layer
Provide examples of protocols used at layers 2 thru 5 of the internet model: - ANS-5)
Application Layer - HTTP (Hypertext Transfer Protocol)
4) Transport Layer - TCP (Transmission Control Protocol
3) Network Layer - IP (Internet Protocol)
2) Data Link Layer - Ethernet
What are the layers of the OSI model?
How does it differ from the Internet model? - ANS-7) Application Layer
6) Presentation Layer
5) Session Layer
4) Transport Layer
3) Network Layer
2) Data Link Layer
1) Physical Layer
Internet model combines layers 5-7 into Application Layer
What is an application architecture? - ANS-Application architecture is the way in which the
functions of the application layer software are spread among the clients and servers in the
network.
What are the four functions of an application program?
What does each function do? - ANS-1) Data storage - holds data for storage or retrieval
2) Data access logic - the processing required to access data
, 3) Application logic - what the app does
4) Presentation logic - the presentation of information to the user and the acceptance of the
user's commands.
How are the application program functions spread across devices in 2-tier and 3-tier
architectures? - ANS-2-tier:
Server >> data
Client >> application & presentation logic
3-tier:
Application server: application logic
Database server: data access & data storage
Client: presentation logic
What is a thin client? - ANS-Places little or no application logic on the client.
(If an application changes, only the server needs to be updated.)
What are the two different types of data seen in communications networks? - ANS-1) Digital -
binary
2) Analog - wave-like
What is the definition of a multi-point circuit?
A dedicated circuit? - ANS-Multi-point >> shared circuit
Dedicated >> One device directly connected to another device
What are half-duplex, full-duplex, and simplex transmissions? - ANS-Half-duplex >> 2-way
transmission only one direction at a time (walkie-talkie)
Full-duplex >> transmit both directions simultaneously with no turnaround time (phone call)
Simplex >> one-way transmission (radio, tv)
What is a multiplexor? - ANS-A device allowing one or more low-speed analog or digital input
signals to be selected, combined and transmitted at a higher speed on a single shared medium
or within a single shared device.
What is multiplexing? - ANS-To break one high-speed physical communication circuit into
several lower-speed logical circuits so that many different devices can simultaneously use it but
still "think" that they have their own separate circuits.
