CS779/879

Assignment #1

Write the following program in C/C++ or any other language:

NAME

GMC - Group Multicast Chat

SYNOPSIS

GMC <multicast-address> <port-number>

DESCRIPTION

· The program creates a single UDP socket U:

The socket joins the multicast group G defined by the two arguments:

<multicast-address> <port-number>

e.g., 224.0.0.1 10123

· The socket U is used to send/receive two types of multicast messages:

1. Heartbeat Messages: sent periodically (e.g., every 5 seconds) to G, indicating it is alive.

2. Chat Messages: typed be the user at the keyboard and sent to G.

· When the socket receives these two types of messages it reacts as follows:

1. Heartbeat Messages: are used to update a group membership list L.

Each member in L has a unique identity I given by the unique pair:

<Host Name> <Sender Process ID>

e.g., vega.cs.odu.edu 7893

Whenever a new member is added/deleted, the program displays the information I

of the added/deleted member and then displays the updated list L.

2. Chat Messages: are displayed to the TTY preceded by the sender’s identity I.

· When the user types:

§ CTRL-C the program displays the list L.

§ CTRL-D the program Exits.

· The following figure is an illustration of the program description:

· The program utilizes the multicast examples and uses the UNIX Signals.

· You may test the Example implementation at:

http://www.cs.odu.edu/~cs779/spring11/assignments/a1/wahab/
Enter the following command on some of the fast machines,

e.g., vega, antares, capella and procyon.

% GMC 224.0.0.1 10123