Implementation and performance evaluation of IGMP snooping supporting multicast functionality on Linux-based Ethernet switches

The objective of this work was to implement Internet Group Management Protocol snooping to support multicast functionality on Linux-based Ethernet switch and carry out its performance evaluation. The implementation of the new functionality required modifications and improvements of two segments of the operating system: some parts of kernel and the user space management software. Algorithms and data structures, used for building multicast table, have been implemented in order to improve switching logic, which is now based on entries in the multicast table. Performance evaluation has been performed in a dedicated environment using a traffic analyzer, able to generate different types of traffic and traffic loads. The results are given for combinations of different loadings and numbers of target ports and prove that the implementation does not only decrease overall network load by reducing redundant broadcast flooding, but also increase the performance of switch by eliminating unnecessary frame forwarding, which eventually leads to lower frame losses and shorter queuing delays.