Loop Detection feature of OpenMUL

This article explains the spanning tree implementation of MUL SDN Controller.


This feature is used when there are one or more occurrences of loop in the network. Spanning Tree implementation makes sure that there are no loops when there are two or more paths to reach a particular network element. Once a loop is occurred due to a broadcast stream then it can be deadly for the network. So, this makes Loop Detection feature an antidote for any network.



Loop detection module uses LLDP for implementing Spanning Tree.  When network element is added to a network, MUL SDN controller sends LLDP packets to every port of the attached network element. By doing this, MUL Controller gets the information about the network topology.

After getting all the information about the neighbours, port states needs to be decided.

Details of the process are :  Continue reading

Hello App – Mul Controller App development note

This post will demonstrate how to write an application for Mul Controller.


1. MuL Controller code and other required packages/libraries. Please refer to this post for more detailed instruction.

2. Average C language knowledge

Sample Application

A sample application for MuL controller can be found here .  Such an application is called a system app since it hooks up with internal apis of MuL controller.  (Another form of application is web-based application which makes use of REST/python apis which is not mentioned here and is covered here )   Continue reading