UDP-client-server

A GO server that relays UDP packets between ports with C clients

Server: The server relays UDP packets between ports.

The server listens for clients on two ports ­ port Pin and port Pout. On port Pin it waits for a single client type A, and once connected it starts sending any packet received from that client to ALL clients type B connected on port Pout.

Client type A: Sends a 1K byte every 100ms to port Pin

Client type B: Connects to the server on port Pout by sending it the command:

CONNECT\r\n

and disconnects from the server by sending it the command:

DISCONNECT\r\n

Client B also measures the amount of data received per second.

You should be able to run a server, ONE client A and as many clients B as possible until you see that transmission rate drops on clients B.

The server is written in Go, the clients are written C language (linux)

How to run:

Server:

1. Make sure you have golang installed on your computer you can download it from here: https://golang.org/dl/
2. run this command at the same directory as the server file: go run server.go
3. ports:
   • clientA: port_in = ":5001"
   • clientB: port_out = ":7777"

clientA: (linux distro)

gcc clientA.c -o clientA Usage: ./clientA <rate (Mb/s)>

clientB: (linux distro)

gcc clientB.c -o clientB -lpthread Usage: ./clientB example: ./clientB 192.168.1.6 7777

Further notes:

• The first client connected on Pin is the chosen client Type A - Any attempt to connect to Pin after the first one is set - will be denied.
• It is assumed that each client will always connect to it's matching port in the server. There are many ways pto add a security check for each connection in order to identify the type of the client. (checksum for example).