ECE 3323 EXAM 2 questions with verified answers
2.1-1 The client-server paradigm. Which of the characteristics below
are associated with a client-server approach to structuring network
applications (as opposed to a P2P approach)?
HTTP uses this application structure.
There is not a server that is always on.
There is a server that is always on.
There is a server with a well known server IP address.
A process requests service from those it contacts and will provide
service to processes that contact i Ans✓✓✓ HTTP uses this application
structure.
There is a server that is always on.
There is a server with a well known server IP address.
2.1-2 The peer-to-peer (P2P) paradigm. Which of the characteristics
below are associated with a P2P approach to structuring network
applications (as opposed to a client-server approach)?
There is not a server that is always on.
HTTP uses this application structure.
There is a server with a well known server IP address.
There is a server that is always on.
,A process requests service from those it contacts and will provide
service to processes that contact it. Ans✓✓✓ There is not a server that
is always on.
A process requests service from those it contacts and will provide
service to processes that contact it.
2.1-3 UDP service. When an application uses a UDP socket, what
transport services are provided to the application by UDP? Ans✓✓✓
Best effort service. The service will make a best effort to deliver data to
the destination but makes no guarantees that any particular segment of
data will actually get there.
2.1-4 TCP service. When an application uses a TCP socket, what
transport services are provided to the application by TCP? Ans✓✓✓
Loss-free data transfer. The service will reliably transfer all data to the
receiver, recovering from packets dropped in the network due to router
buffer overflow.
Flow Control. The provided service will ensure that the sender does not
send so fast as to overflow receiver buffers.
Congestion control. The service will control senders so that the senders
do not collectively send more data than links in the network can
handle.
2.2-1 "HTTP is stateless." What do we mean when we say "HTTP is
stateless"? In answering this question, assume that cookies are not
used. Check all answers that apply.
,An HTTP server does not remember anything about what happened
during earlier steps in interacting with this HTTP client.
We say this when an HTTP server is not operational.
The HTTP protocol is not licensed in any country.
An HTTP client does not remember anything about what happened
during earlier steps in interacting with any HTTP server.
An HTTP client does not remember the identities of the servers with
which it has interacted. Ans✓✓✓ An HTTP server does not remember
anything about what happened during earlier steps in interacting with
this HTTP client.
2.2-1 Simple HTTP GET request response time. Suppose an HTTP client
makes a request to the gaia.cs.umass.edu web server. The client has
never before requested a given base object, nor has it communicated
recently with the gaia.cs.umass.edu server. You can assume, however,
that the client host knows the IP address of gaia.cs.umass.edu.
How many round trip times (RTTs) are needed from when the client
first makes the request to when the base page is completely
downloaded, assuming the time needed by the server to transmit the
base file into the server's link is equal to 1/2 RTT and that the time
needed to transmit the HTTP GET into the client's link is zero? (You
should take into account any TCP setup time required before the HTTP
GET is actually sent by the client, the time needed for the server to
transmit the requested object, and any propagation delays not
accounted for in these amounts of time.) Ans✓✓✓ 2.5 RTT
, 1 RTT(TCP SETUP) + 1/2 RTT(SERVER TRANSMISSION) +
1RTT(PROPAGATION) = 2.5 RTT
2.2-10 HTTP/2 versus HTTP/1.1. Which of the following are changes
between HTTP 1.1 and HTTP/2? Note: select one or more answers.
HTTP/2 allows a large object to be broken down into smaller pieces,
and the transmission of those pieces to be interleaved with
transmission other smaller objects, thus preventing a large object from
forcing many smaller objects to wait their turn for transmission.
HTTP/2 has many new HTTP methods and status codes.
HTTP/2 provides enhanced security by using transport layer security
(TLS).
HTTP/2 allows objects in a persistent connection to be sent in a client-
specified priority order. Ans✓✓✓ HTTP/2 allows a large object to be
broken down into smaller pieces, and the transmission of those pieces
to be interleaved with transmission other smaller objects, thus
preventing a large object from forcing many smaller objects to wait
their turn for transmission.
HTTP/2 allows objects in a persistent connection to be sent in a client-
specified priority orde
2.1-1 The client-server paradigm. Which of the characteristics below
are associated with a client-server approach to structuring network
applications (as opposed to a P2P approach)?
HTTP uses this application structure.
There is not a server that is always on.
There is a server that is always on.
There is a server with a well known server IP address.
A process requests service from those it contacts and will provide
service to processes that contact i Ans✓✓✓ HTTP uses this application
structure.
There is a server that is always on.
There is a server with a well known server IP address.
2.1-2 The peer-to-peer (P2P) paradigm. Which of the characteristics
below are associated with a P2P approach to structuring network
applications (as opposed to a client-server approach)?
There is not a server that is always on.
HTTP uses this application structure.
There is a server with a well known server IP address.
There is a server that is always on.
,A process requests service from those it contacts and will provide
service to processes that contact it. Ans✓✓✓ There is not a server that
is always on.
A process requests service from those it contacts and will provide
service to processes that contact it.
2.1-3 UDP service. When an application uses a UDP socket, what
transport services are provided to the application by UDP? Ans✓✓✓
Best effort service. The service will make a best effort to deliver data to
the destination but makes no guarantees that any particular segment of
data will actually get there.
2.1-4 TCP service. When an application uses a TCP socket, what
transport services are provided to the application by TCP? Ans✓✓✓
Loss-free data transfer. The service will reliably transfer all data to the
receiver, recovering from packets dropped in the network due to router
buffer overflow.
Flow Control. The provided service will ensure that the sender does not
send so fast as to overflow receiver buffers.
Congestion control. The service will control senders so that the senders
do not collectively send more data than links in the network can
handle.
2.2-1 "HTTP is stateless." What do we mean when we say "HTTP is
stateless"? In answering this question, assume that cookies are not
used. Check all answers that apply.
,An HTTP server does not remember anything about what happened
during earlier steps in interacting with this HTTP client.
We say this when an HTTP server is not operational.
The HTTP protocol is not licensed in any country.
An HTTP client does not remember anything about what happened
during earlier steps in interacting with any HTTP server.
An HTTP client does not remember the identities of the servers with
which it has interacted. Ans✓✓✓ An HTTP server does not remember
anything about what happened during earlier steps in interacting with
this HTTP client.
2.2-1 Simple HTTP GET request response time. Suppose an HTTP client
makes a request to the gaia.cs.umass.edu web server. The client has
never before requested a given base object, nor has it communicated
recently with the gaia.cs.umass.edu server. You can assume, however,
that the client host knows the IP address of gaia.cs.umass.edu.
How many round trip times (RTTs) are needed from when the client
first makes the request to when the base page is completely
downloaded, assuming the time needed by the server to transmit the
base file into the server's link is equal to 1/2 RTT and that the time
needed to transmit the HTTP GET into the client's link is zero? (You
should take into account any TCP setup time required before the HTTP
GET is actually sent by the client, the time needed for the server to
transmit the requested object, and any propagation delays not
accounted for in these amounts of time.) Ans✓✓✓ 2.5 RTT
, 1 RTT(TCP SETUP) + 1/2 RTT(SERVER TRANSMISSION) +
1RTT(PROPAGATION) = 2.5 RTT
2.2-10 HTTP/2 versus HTTP/1.1. Which of the following are changes
between HTTP 1.1 and HTTP/2? Note: select one or more answers.
HTTP/2 allows a large object to be broken down into smaller pieces,
and the transmission of those pieces to be interleaved with
transmission other smaller objects, thus preventing a large object from
forcing many smaller objects to wait their turn for transmission.
HTTP/2 has many new HTTP methods and status codes.
HTTP/2 provides enhanced security by using transport layer security
(TLS).
HTTP/2 allows objects in a persistent connection to be sent in a client-
specified priority order. Ans✓✓✓ HTTP/2 allows a large object to be
broken down into smaller pieces, and the transmission of those pieces
to be interleaved with transmission other smaller objects, thus
preventing a large object from forcing many smaller objects to wait
their turn for transmission.
HTTP/2 allows objects in a persistent connection to be sent in a client-
specified priority orde
