Comparative analysis of LLQ traffic scheduler to FIFO and CBWFQ on IP phone-based applications (VoIP) using Opnet (Riverbed)

Nowadays, world is on going to “Convergence Era”, where data, voice, and video overcome to pass through same network, like IP network. Unfortunately, the fast growth of application technology has not been supported yet by default IP network in the case of quality of service. We have known, that voice over IP services have sensitivity to delay, jitter and latency. And it require of different bandwidth which is also required some service guarantee. How to comparing queue mechanism of VoIP attributed to QoS?. In this case, we need to give guarantee of QoS relied on operation of data packages to be delivered along with its scheduling. Scheduling represent queue mechanism from an applying of network QoS's, that is an arrangement process of an exit and entry of assumed data packages queuing exceed CIR (Committed Information Rate) specified. Regulation of this data exit and entry can be formed with specified classification. This research compare queue method of First In First Out (FIFO) with two algorithm type of WFQ scheduling which at most used, that is Class Based Weighted Fair Queuing (CBWFQ) and Low Latency Queuing (LLQ). Based on delay, jitter, and MOS (Mean Opinion Score) obtained, LLQ give a better network performance.