Performance Analysis of Priority Queue and Weighted Fair Queue in VoIPv6 Amani Alged Fetaha Osman 1, Khalid Hamid Bilal 2 and Amin Babiker A/nabi Mustafa 3 1 amaniai_alged@yahoo.com 2 dr.khalidbilal@hotmail.com 3 College of Engineering, Al Neelain University, Sudan amin31766@gmail.com Abstract Voice over IP is a one of the applications which are increasing with the rapid develop of technologies, and need to monitor and control the level of quality at high degree. The transition from IPv4 to IPv6 will present significant improvements for internet IPv6 and is more efficient than IPv4. This paper presents a properties of queuing mechanisms used in buffering signal of voice by analyze the performance of VoIPv6 from the point of QoS when use different queuing mechanisms. OPNET Modular was used as a simulation tool in this study to analysis the performance of VoIP. Keywords: QoS, IPv6, VoIP, Performance, queuing mechanisms. 1. Introduction Today; there is a growing in real-time voice communication using Internet Protocol (IP), VOIP was becoming one of the most widely used technologies. On the other hand the capacity of systems in communication network was increased as the result of increase number of users. With these improvements of technologies we need to ensure and control of quality by using all available mechanisms that Challenge various problems comes from the system capacity and causes degradation of the level of quality. Voice is being sensitive to jitter, delay and packet loss; the voice packets are marked and queued to analyzed four different queuing mechanisms such as Priority Queue (PQ), Weighted Fair Queue (WFQ), Class-Based Weighted Fair Queue (CBWFQ) and Low Latency Queue (LLQ). Each queuing mechanism has their own feature; in PQ higher priority queue has strict priority over lower ones. WFQ provides fair queuing, which divides the available bandwidth across queues of traffic flow 7 based on weights.cbwfq is an extended from of WFQ, which guarantees minimum bandwidth based on user-defined traffic classes. LLQ is the combination of PQ and CBWFQ. Some projects are understood the effect of queuing mechanisms and classifying of traffic. Results obtained from these projects can be used in determining the efficient queuing technique. And concluded that LLQ has better performed than any other queuing mechanisms. When LLQ was used, it kept an acceptable packet loss less than 1% the delay of the voice packets was nearly. LLQ can be used for the QoS parameters assurance in VoIP networks. [1]The queuing disciplines are: First-in-first-out (FIFO) queuing, Priority queuing(pq), Weighted-Fair queuing.(wfq). FIFO is an acronym for First In First Out This expression describes the principle of a queue or first-come first serve behavior: what comes in first is handled first, what comes in next waits until the first is finished etc. Thus it is analogous to the behavior of persons standing in a line or Queue where the persons leave the queue in the order they arrive. First In First Out (FIFO) is the most basic queuing discipline. In FIFO queuing all packets are treated equally by placing them into a single queue, then servicing them in the same order they were placed in the queue. FIFO queuing is also referred to as First Come First Serve (FCFS) queuing [2]. Priority Queuing assigns multiple queues to a network interface with each queue being given a priority level. A queue with higher priority is processed earlier than a queue with lower priority. Priority Queuing has four preconfigured queues, high medium, normal and low priority queue. By default each of these queues has 20, 40, 60 and 80 packets capacity [3]. Many studies and research are found in performance of voice over internet protocol and
described the properties of audio code these previous studies are illustrated in table below: Table 1: Previous Studies on Queuing Mechanisms in Voice over Internet Protocol Author Title of study Type of study Mohammad Shahidul Islam & Syed Nasir Mehdi Vijayanand S. Ballapuram Sarhan M. Musa Mahamadou Tembely Matthew N. O. Sadiku Pamela H. Obiomon K.Balasundaram, T.Velmurugan, R.Suresh Payal*, Richa Gupta Dr. Hussein A. Mohammed*, Dr. Adnan Hussein Ali**,Hawraa Jassim Mohammed* How Different QoS Mechanisms Affect VoIP QoS Metrics Impact of Queuing Schemes and VPN on the Performance of a Land Mobile Radio VoIP System Modeling and Simulation of Queuing Scheduling Disciplines on Packet Delivery for Next Generation Internet Streaming Applications Performance Analysis of Queuing Disciplines for Difference Services Using OPNET Tool Review on Optimization of Computer Networks Using QOS Msc thesis Msc thesis Paper Paper Paper Place of publication School of Information Science, Computer and Electrical Engineering,Halmstad University, Technical Report, IDE1070, Faculty of thevirginia Polytechnic Institute and State University International Journal of Computer and Information Technology (ISSN: 2279 0764). Volume 03 Issue 02, International Journal of Scientific Engineering and Technology (ISSN: 2277-1581), Volume No.3, Issue No.1 pp: 47-50 International Journal of Advanced Research in Computer Science and Software Engineering, Volume 4, Issue 4, April 2014 ISSN: 2277 128X Date of publicati on June 2010 [5] April 16, 2007 [6] March 2014[7] Jan 2014 [8] April 2014 [9], January 2013[10] All these conventional studies had evaluated and analyzed of the performance of voip when used internet protocol version 4 and internet protocol version 6. They investigated the objective voice quality of VoIP networks, and accessed to: To improve the quality of VoIP calls we cannot go into 8 switching or hardware techniques which are expensive and are not meant for VoIP basically, but by enhanced and improve performance analysis. These previous studies had successfully analyzed the network performance for, PQ, and WFQ with different kind streaming applications such as VoIP
using OPNET simulation tools to achieve the QoS. These studies had also studied various parameters to improve queuing technique in more acceptable and optimized networks. 2. Internet Protocol Version 6 Both IPv4 and IPv6 define data communication from one computer to another computer over the internet network layer. IPv6 has a very large address space and consist of 128 bits as compared to 32 bits in IPv4. It is now possible to support 2 128 unique IP addresses. IPv6 implement QoS with the help of classification and marking (of IP packets) to ensure a reliable VOIP infrastructure. With the help of classification and marking technique, the network can identify packets or traffic flows and then can assign certain parameters within the packet headers in order to group them. IPv6 provide a traffic class field (8 bits) in own header that can intend for originating nodes and forwarding routers to identify and distinguish between different classes or priorities of IPv6 packets [11]. The IPv6 is provide a mechanism for carrying real-time traffic while IPv4 is working by best effort service that means IP it not discover the packet which can be : Lost,Delay out- of- order delivery,corruption [12]. 3. Quality of Services Real time applications must adjust their QoS according to the heterogeneous terminals with variable QoS requirements and support. The multitude advances attained in terminal computers, along with the introduction of mobile hand-held devices, and the deployment of high speed networks have led to a recent surge of interest in Quality of Service (QoS) for multimedia applications. Computer networks able to support multimedia applications with diverse QoS performance requirements are evolving. To ensure that multimedia applications will be guaranteed the required QoS, it is not enough to merely commit resources. It is important that distributed multimedia applications ensure end-to-end QoS of media streams, considering both the networks and the end terminals. Presently, there are various kinds of networks; wired and wireless that co-exists with each other. These networks have QoS characteristics that are drastically different and whose degree of variability of the different QoS parameters, such as bandwidth, delay and jitter, differ considerably. Furthermore, there are various kinds of terminals, such as desktop computers, laptop computers, and cell phones, each with ISO defines QoS as a concept for determining the quality of the offered networking services. 4. Simulation In the simulation model, OPNET software was used to build a small Wirelesslan and then to exam the effect of Priority Queue (PQ), Weighted Fair Queue (WFQ) on the performance of VoIPv6. The network topology is shown in fig (1): Figure 1: Network Topology 9
Table 2: Simulation Environment Number of nodes 18 nodes Network scale Office Specify size 100*100 m 2 Technology 802.11b direct sequence Data rate 11 Mbps Link model 100BaseT full duplex Queuing mechanism PQ, WFQ Application Voice over IP call (PCM Quality) Duration of simulation 300 second 5. Results Figure 2: The Graphical Representations i. Value of Jitter ii. Packet Delay Variation iii. End to End Delay 10 iv. Traffic Received (bytes/sec)
v. Traffic Sent (bytes/sec) 6. Results Discussion From all previous graphics, the observation on jitter for a queuing mechanism shows that WFQ is least affected by jitter where PQ had higher impact of jitter. From the packet delay variation WFQ can perform better, but have end to end delay value larger than PQ. Both two mechanisms have no packet loss, because the traffic sent equal traffic received. 7. Conclusion In this paper, OPNET simulation tools used to analysis the performance of voipv6 when using PQ, and WFQ to achieve the QoS. We observed that PQ has better performance than WFQ In the term of amount of traffic and end to end delay, but have poor performance in term of delay variation. That means PQ performs better when the data stream go in long distance but the WFQ have better perform when the data go in short distance. By short term; the best performance need to make PQ and WFQ work together. 11 References [1] Arjuna Mithra Sreenivasan, Analysis of QoS in Real Time VoIP Network. Napier University. 06 Jun. 08 FIFO (First in First out), http://www.daxnetworks.com/technology/tech Dost/TD- 032206.pdf [2] Hermawan Widiyanto, AWANetwork http://awanetwork.blogspot.com /2007/09 [3] Mohammad Mirza Golam Rashed and Mamun Kabir, A Comparative Study of Different Queuing Techniques in VOIP, Video Conferencing and File Transfer. Daffodil International University Journal of Science And Technology, Volume 5, Issue 1, January 2010, p (37-47). [4] Mohammad Shahidul Islam & Syed Nasir Mehdi, How Different QoS Mechanisms Affect VoIP [5] QoS Metrics. School of Information Science, Computer and Electrical Engineering,Halmstad University, Technical Report, IDE1070, June 2010. [6] Vijayanand S. Ballapuram, Impact of Queuing Schemes and VPN on the Performance of a Land Mobile Radio VoIP System. Faculty of the
Virginia Polytechnic Institute and State University, April 16, 2007. [7] Sarhan M. Musa Mahamadou Tembely Matthew N. O. Sadiku Pamela H. Obiomon, Modeling and Simulation of Queuing Scheduling Disciplines on Packet Delivery for Next Generation Internet Streaming Applications. International Journal of Computer and Information Technology (ISSN: 2279 0764). Volume 03 Issue 02, March 2014. [8] K. Balasundaram, T. Velmurugan, R. Suresh, Performance Analysis of Queuing Disciplines for Difference Services Using OPNET Tool. International Journal of Scientific Engineering and Technology (ISSN : 2277-1581), Volume No.3, Issue No.1 pp : 47-50, jan2014 [9] Payal*, Richa Gupta, Review on Optimization of Computer Networks Using QOS. International Journal of Advanced Research in Computer Science and Software Engineering, Volume 4, Issue 4, April 2014 ISSN: 2277 128X [10] Dr. Hussein A. Mohammed*, Dr. Adnan Hussein Ali**, Hawraa Jassim Mohammed*, The Affects of Different Queuing Algorithms within the Router on QoS VoIP application Using OPNET. International Journal of Computer Networks & Communications (IJCNC) Vol.5, No.1, January 2013. [11] E.M. Dogo, A. Ahmed and O.M. Olaniyi, Cross Layer Integration Approach for Improving QoS for IPv6 Based VOIP / Department of Computer Engineering, /Federal University of Technology P.M.B 65, Minna, Niger State Nigeria in International Journal of Engineering and Technology Volume 4 No. 8, August, 2014 [12] Douglas E. Comer, Computer Networks and Internets, Fifth Edition. Department of Computer Sciences, Purdue University, West Lafayette, IN 47907. 12