CS 779/879
Design of Network Protocols
Spring 2007
Final Exam

Time 2 & 1/2 hours

Open: Textbooks & Notes

Closed: Notebooks

Name:

Unix Login:

Q1: (15 points)

In the system call:

socket (arg1, arg2, arg3);

List all possible values that we have discussed in our class for:

arg1:

arg2:

ag3:

Q2: (15 points)

To read from a socket we may use one of the following system calls:

read, recv, recvfrom.

Describe under what conditions we must use:

recv:

recvfrom:

Q3: (20 points)

Part1:

Assume the following program is running at host: (something)128.82.4.210, fe80::203:baff:fe2a:67ff).

% DayTimeServer4SctpS

Provide all possible alternative arguments to each of the following programs to obtain the daytime from that server:

Ø DayTimeClient4SctpS

Ø DayTimeClient6SctpS

Ø DayTimeClient4SctpQ

Ø DayTimeClient6SctpQ

Part 2:

Assume the following program is running at host: (something)128.82.4.210, fe80::203:baff:fe2a:67ff).

% DayTimeServer6SctpS

Provide all possible alternative arguments to each of the following programs to obtain the daytime from that server:

Ø DayTimeClient4SctpS

Ø DayTimeClient6SctpS

Ø DayTimeClient4SctpQ

Ø DayTimeClient6SctpQ

Q4: (15 points)

In testing assignment #5 for student (S), Dr. Wahab executed the server GCS and all chatting clients (sctp and mcast) on the same machine.

Dr. Wahab noticed that when an sctpt client types a message M, all other sctp clients get the message M twice.

Ø What is the most plausible cause for this problem?

Ø How student S can fix this problem?

Q5: (35 points)

Write a program called GDS (General Daytime Server) with the following description:

% GDS <port>

To send the daytime to any request from any client that arrives to <port>.

The program can handle any type of client with any of the following transport protocol types:

tcp, udp, sctp

and any IP protocol type:

ipv4, ipv6

To improve the readability of your code:

- do not write any include statements and

- do not check for any errors for example:

if (socket (. . .)) < 0)

perror(. . .);

Should be written simply as:

socket (. . .);