mangledbottles / OpenFlow-Forwarding

Protocol developed using UDP to forward messages over a layer of Routers managed by a Controller

OpenFlow UDP Socket Protocol

This project is an implementation of the OpenFlow Protocol using the Node.js UDP Datagram Socket Library. The core functionality of this system provides a front-end user interface for the client which connects to the OpenFlow Network.

The OpenFlow network consists of a number of routers that forward messages and are controlled by a centralised switcher.

The switcher is a simple device that allows the routers to communicate with each other. It also allows the routers to communicate with the network.

Project Structure

This project is divided into the following sections:

• /Server
  • Writen in NodeJS using the dgram and Typescript module to create a Switcher and a number of Routers.
• /Client
  • An ElectronJS desktop GUI application which provides a user interface that connects to the OpenFlow Network (in /Server). Built with VueJS and Typescript

Downloading Repository

git clone https://github.com/mangledbottles/OpenFlow-Forwarding.git

cd OpenFlow-Forwarding

# See documentation inside /Client for installation of ElectronJS application
# See documentation inside /Server for installation of NodeJS Switcher and Routers

Communication Protocol

Communication between the Switcher, multiple Routers and multiple Clients is handled by a universal Protocol Type system.

Protocol Type	Description	Components [Origin -> Destination]
#0	Switcher accepted this current Router on network	Switcher -> Router
#1	New Router Detected on Network by Switcher	Router -> Switcher
#2	Router querying Switcher for information about Clients from Forwarding Table	Router -> Switcher
#3	Client connecting to Router to get information about Forwarding Table	Client -> Router
#4	Router received information about a Client from Switcher via Flowtable	Switcher -> Router
#5	Router received message instructions from Client to send message over the network	Client -> Router
#6	Router received updated information about current Router	Switcher -> Router

Project Functionality

1. Switcher is started to commence the network
2. 3 Routers are started and join the network
3. A client ("Alice") joins the network and is connected by the Switcher
4. A secondary client ("Bob") joins the network and is connected by the Switcher
5. Alice sends a message to Bob
6. The message is forwarded from Alice to Router 1 to Router 2 to Router 3 and finally to Bob.

Wireshark

The following diagram shows the communication between the Switcher, Routers and Clients.

Example 1: Router connecting to Network via Switcher

No.	Time	Source	Destination	Protocol	Length	Info
5	10.382165	127.0.0.1	127.0.0.1	UDP	61	65469 -> 51510

Hexadecimal Payload	Base10 Decoded
0000 0020 7b 22 74 79 70 65 22 3a 31 2c 22 6d 65 73 73 61	{"type": 1, "messa
0010 67 65 22 3a 22 52 6f 75 74 65 72 22 7d	ge":"Router"}

• Router on port 65469 is sending a message to the Switcher on port 51510 trying to join the network.
• Type is set to 1, as seen in Communication Table protocol type 1.

References

• [0] OpenFlow - https://en.wikipedia.org/wiki/OpenFlow
• [1] Node Datagram Library - https://nodejs.org/api/dgram.html