Assignment 2
The Trivial File Transfer Protocol (TFTP) is an Internet software utility for
transferring files that is simpler to use than the File Transfer Protocol (FTP) but
less capable. It is used where user authentication and directory visibility are not
required. For example, it is used by Cisco routers and switches to transfer
images of the operating system from/to the devices.
NOTE: TFTP's port is 69 (a system/OS port). This is below 1024 and therefore
you cannot bind a Socket to it unless you have administrative access rights on
the machine you are working. To avoid any complications you can use any port >
1024 to bind server sockets.
Task 1: Implementation of the Trivial File
Transfer Protocol (TFTP)
For this task you need to implement (in Java) the Trivial File Transfer Protocol
(TFTP) as specified in RFC 1350 (Links to an external site.)Links to an external
site.. You will submit source code for a client and server application that 'speak'
the TFTP protocol. You will built your protocol on top of UDP. Compared to the
specifications in the RFC, you will implement a slightly simplified version:
Support for octet mode only. The files should be transferred as a raw
sequence of bytes. Do not read, write or transfer files as characters.
Support only for error handling when the server is unable to satisfy the
request because the file cannot be found.
No support for error handling when data duplication occurs.
The client and server applications should be simple Java console applications.
The server should operate (i.e. read and write files) in the directory where it is
started from. The server should support simultaneous file transfers to and from
multiple clients. The client should just read command line arguments (or have a
very simple console-based menu - e.g. "press 1 to store file, press 2 to retrieve
file") and execute user commands (i.e. reading or writing a file).
Hint: the simplest way to implement timeouts is by calling
代写TFTP留学生作业、Java课程设计作业代做、Java程序语言作业调试
the setSoTimeout() method on the DatagramSocket objects (assuming that you
are using blocking I/O). If the timeout expires,
a java.net.SocketTimeoutException is raised, though the DatagramSocket is still
valid.
Task 2: Implementation of an even simpler
version of TFTP on top of TCP
For this task you will use TCP sockets to implement a protocol that operates like
TFTP (i.e. supports only read and write operations). Given that TCP supports
in-order, reliable data transport, you should not implement the relevant
mechanisms described in RFC 1350 (ACKs, retransmissions). The client and
server applications should be equally simple, as in Task 1. The server must be
able to handle multiple file transfers.
Marking Criteria
You should make sure that your code compiles. Code which does not compile
will receive at most 20%.
I will assess your assignment using the following criteria:
TFTP-UDP-Server (35%)
Is the server-side of the protocol fully and correctly implemented
(based on the specifications in the RFC)? i.e. read/write requests,
acknowledgments, timeouts, error handling, support for simultaneous
file transfers.
TFTP-UDP-Client (30%):
Is the client-side of the protocol fully and correctly implemented (based
on the specifications in the RFC)? i.e. read/write requests,
acknowledgments, timeouts, error handling.
TFTP-TCP-Server (10%)
Is the server-side of the protocol fully and correctly implemented? i.e.
read/write requests, error handling, support for simultaneous file
transfers.
TFTP-TCP-Client (10%):
Is the client-side of the protocol fully and correctly implemented? i.e.
read/write requests, error handling.
Description of Protocols (10%):
Is there description for both protocols and how/where the specifications
are implemented?
Is the description well-written with clear references to the source code?
Other Characteristics (5%):
Is the code commented appropriately?
Is it indented correctly?
? Is naming of variables and methods sensible?
Submission Guidelines
You should submit the coursework by the deadline posted on Sussex
Direct (and the submission link on Canvas). Standard penalties for late
submissions will apply. You will need to submit a .zip file containing the
following:
Well-formatted and well-documented source code (written in Java) in 4
separate Netbeans projects that can be compiled and run. The
Netbeans projects, named TFTP-UDP-Server, TFTP-UDP-Client,
TFTP-TCP-Server and TFTP-TCP-Client, respectively, will include all
required source code to execute the 2 different file transfer protocols.
A short report (up to 2000 words) describing your protocols, the source
code and the design decisions that you made.
Please do not put your names on your submissions, but do include your
candidate number. Failure to submit source code, as described in the first
bullet, will result to a zero mark as I will not be able to assess your
programming effort.
Plagiarism and Collusion
The coursework you submit is supposed to have been produced by
you and you alone. This means that you should not: work together with
anyone else on this assignment
give code for the assignment to other students
request help from external sources
do anything that means that the work you submit for assessment is not
wholly your own work, but consists in part or whole of other people’s
work, presented as your own, for which you should in fairness get no
credit
If you need help ask your tutor The University considers it misconduct to
give or receive help other than from your tutors, or to copy work from
uncredited sources, and if any suspicion arises that this has happened,
formal action will be taken. Remember that in cases of collusion (students
helping each other on assignments) the student giving help is regarded by
the University as just as guilty as the person receiving help, and is liable
to potentially receive the same penalty. Also bear in mind that suspicious
similarities in student code are surprisingly easy to spot and sadly the
procedures for dealing with it are stressful and unpleasant. Academic
misconduct also upsets other students, who do complain to us about
unfairness. So please don’t collude or plagiarise.
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