A top-down approach to VoD traffic transmission over DiffServ domain using AF PHB class (original) (raw)

RECONFIGURABLE DIFFSERV BASED QOS MODEL FOR REAL-TIME TRAFFIC

The main architectures of the Internet adopts the best-effort model for traffic control. It is an unable to guarantee a timely delivery of data. To address this problem, a " differentiated services " (DiffServ) is proposed by the IEFT (Internet engineering task force) as a simple and scalable solution for providing the quality of service (QoS) for Internet applications with various levels of services. In DiffServ, scheduling disciplines play an important role in achieving the required level of service in terms of various criteria (e.g., delay, jitter, throughput, and packet loss). In this paper, a Reconfigurable Scheduler Model (RSM) for real-time traffic through DiffServ router has been designed and implemented using OPNET Modular. The proposed scheduler applies the three most widely accepted queue schedulers in DiffServ routers; Priority Queuing (PQ), Class Based Weight Fair Queuing (CBWFQ) and Modified Deficit Round Robin (MDRR). The voice traffic can be scheduled using strict priority queue scheduler while the video and data traffic are scheduled by the CBWFQ and MDRR schedulers which can be interchanged according to the queue delay of the video traffic to provide better QoS. The performance evaluation shows an improvement in QoS parameters of voice and video traffics. Introduction:-Quality of Service (QoS) is a measure of the ability of network and computing systems to provide different levels of services to selected applications within a network. It is one of the necessary items, especially in real time applications. Different kinds of applications and users require different degrees quality of service (QoS). Voice traffic is time sensitive and intolerant of delay, jitter and packets loss. Video is also intolerant of delay and packets loss, with additional complication of being very bursty at times of arrivals.

Efficient MPEG video traffic shaping for the next generation Internet

1999

Abstract The Internet Engineering Task Force (IETF) has defined the Guaranteed Service (GS) with firm delay and bandwidth guarantees in the Integrated Services model for supporting real-time services. Before setting up a GS flow, the traffic parameter of the source have to be specified in terms of a number of token bucket traffic descriptors. The source must conform to these descriptors by shaping its traffic. In this paper we study a novel traffic shaper for efficient transmission of MPEG video streams over GS.

On the Reduction of Congestion for Multimedia Streaming in Diffserv Networks

2000

In this paper, we propose a simple meter and classification scheme, specifically designed for real-time multimedia streaming applications in Diffserv QoS networks. This is based upon the observation that conformance deterioration takes place on such networks for all traffic of variable-size packets. We show that it is simple to detect, shape and drop packets which experience exceeding delay, thus reducing