Video streaming through caches

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.



With the high usage of the internet , the efficient distributed video of the strored information from the server to the end users had become a major concern. This project probably improves the efficiency for video streaming using caches. Mainly the video applications are used by the clients to view the video. The currently implemented streaming functionality, however, presents many technical challenges at the client side, server side and the network that have not yet been efficiently resolved. The main goal is to provide the probably efficient video streaming to the clients. The client in a distributed environment is connected to the server through a network. In the intranet the client machines are the self organized into the P2P structured form which is to provide a larger storage for the media. Proxy also is an important element in the quality of the streaming. The P2P management system are coordinated and collaboration are effectively conducted

The proxy plays an important role in the quality of the video streaming because of its dedicated and stabled nature.

AIM: The main aim of the project is to improve the efficiency of the distributed video from server to end user using caching system

Objective :

1.TO investigate on the current advances and developments in the video streaming.

2. To carry out the comparative evaluation on the performances of the top solution

3. To solve the scalability problem of proxy based techniques,

4.To deliver the high-quality media content to clients using proxy based peer - peer caching system.

5.To achieve the objectives the proposed system attempts to address both the scalability and the reliability issues of streaming media delivery in a cost-effective way.

6.To explore a possibility of simulation for proper solutions.

7.To evaluate the proposed solutions with comparison and published solutions.


The proxy - The proxy is the bootstrap site of the P2P system and the interface between the P2P system and media servers. When an object is requested for the first time or when no peer in the system is able to serve a streaming request, the proxy is responsible to fetch the requested media data from the remote server, divide the object into small segments, and cache them locally.

Client peers -receiving the media streaming service, which are self-organized into a P2P overlay network.

There are three functionalities of the peer 1) A peer is a client that requests media data

2) A peer is a streaming server that provides media streaming service to clients. Each peer caches the media data in segments while its content accessing is in progress and shares the cached data with other peers in the system. 3) A peer is also acting an index server that maintains a subset of indices of media segments in the system for content location. Peers in our system are self-organized into a structured P2P overlay supporting a distributed hash table, which maps the identifier of each media segment to the index of the segment.

The distributed hash tables are designed in our system for content locating and data

management: publish, unpublish, request, update, and notify. All these operations can be built on top of the common functionalities provided by distributed hash tables: put(key,value), get(key), and delete(key).

Existing System : Existing Internet streaming media delivering techniques are either based on a client-server model, such as, proxy caching and server replications by CDNs, or based on a client-based P2P structure. Special content delivery networks (CDNs) have

been built to replicate media servers across the Internet to move the contents close to the clients. This approach is performance-effective but not cost-effective. The second approach is to utilize existing proxies to cache media data, which is cost-effective but not scalable due to limited storages and bandwidths of centralized servers. The third approach is to build client-based P2P overlay networks for media content delivery, which is highly cost effective but does not guarantee the quality of service because the capacities (CPU, storage, and bandwidth) of peers can be heterogeneous and their availabilities can be transient.

Proposed System : P2P assisted proxy system significantly improves the quality of streaming service mainly because the caching storage in P2P assisted proxy has been effectively and highly enhanced. Thus, media segments can be timely and smoothly delivered to any end user in the system either by other end users or/and by the proxy collaboratively. The collaboration and coordination between the proxy and its P2P clients in our system address the scalability problem of the proxy-based technique, and also eliminate the concern of unstable quality of services by only relying on self-organized clients. To improve the reliability and maximize the utilization of cached data in each peer, a model is proposed to analyze the cache redundancy in our peer to peer caching system where peers are free to come and go. Our modeling results give the optimal replica distribution in such a system, and provide the guidance to cache replacement policy design. To improve the cache utilization, a model has been proposed and designed for the collaboration and coordination between the proxy and clients to make the entire streaming media system both performance-effective and cost-efficient.

Literature review:

MiddleMan is a collection of proxy servers that, as an aggregate, cache video files within a well-connected network. By cooperatively caching video files, MiddleMan can have a large aggregate cache while placing minimal load on each participating client. The characteristics of videos stored on the Internet today suggest that caching would be effective. Such features include high bandwidth requirements and the fact that videos rarely change. Our survey of video data on the web shows that sustained bandwidths of approximately 1 Mbps are required in order to stream most MPEG, AVI, and QuickTime video files stored on the web today. These bandwidth requirements make video files susceptible to Internet brownouts. By caching video documents close to the client, MiddleMan simultaneously mitigates the unreliability of the Internet, improves access latency, and reduces overall traffic. The key observation driving our approach is that requests to a video server tend to exhibit locality of reference. Some videos are much more popular than others. Hence, it is possible to exploit caching techniques that reduce redundant video accesses to the server[1].

The design and implementation issues related to disk and memory utilization at a helper that inter-operates with media clients and servers using RTSP and RTP as their control and data protocols, respectively. This work demonstrates the advantage and feasibility of implementing a caching system for streaming media within the current Internet framework. This paper proposed a design and implementation of a caching system for streaming media, which utilizes its local memory and disk resources to reduce network and server load, while also improving the video and audio quality perceived by end users. In particular, request aggregation, prefix caching and rate control mechanisms are used in the system design. The effectiveness of the system is validated through performance results from prototype implementation. As expected, the caching system reduces network and server load and improves client start-up latency[2].

The workload analysis of today's enterprise media servers. This analysis aims to establish a set of properties specific for enterprise media server workloads and to compare them with well known related observations about web server workloads. The proposed two new metrics to characterize the dynamics and evolution of the accesses, and the rate of change in the site access pattern, and illustrate them with the analysis of two different enterprise media server workloads collected

over a significant period of time. Another goal of our workload analysis study is to develop a media server log analysis tool, called Media Metrics, that produces a media server trace to access profile and its system resource usage in a way useful to service providers. The analysis aimed to establish a set of properties specific for the enterprise media server workloads and compare them with the well known related observations about the web server workloads. In particular, we observed high locality of references in media _le accesses for both workloads. Similar to previous web workloads studies, our analysis of the media popularity distribution revealed that it can be approximated by Zipf-like distribution with parameter in a range. The interesting new observation is that the time scale plays an important role in this approximation[3].

A peer-to-peer streaming solution to address the on-demand media distribution problem. We identify two issues, namely the asynchrony of user requests and heterogeneity of peer network bandwidth. Our key techniques to address these two issues are cache-and relay and layer-encoded streaming. A unique challenge of

layered peer-to-peer streaming is that the bandwidth and data availability of each receiving peer are constrained and heterogeneous, which further limits the bandwidth and data availability of its downstream node when it acts as the supplying peer. This challenge distinguishes our work from existing studies on layered multicast. Our experiments show that our solution is efficient at utilizing bandwidth resource of supplying peers, scalable at saving server bandwidth consumption, and optimal at maximizing streaming qualities of all peers[6].

The demand of delivering streaming media content in the Internet has become increasingly high for scientific, educational, and commercial applications. Three representative technologies have been developed for this purpose, each of which has its merits and serious limitations. Infrastructure based CDNs with dedicated network bandwidths and powerful media replicas can provide high quality streaming services but at a high cost. Server-based proxies are cost effective but not scalable due to the limited proxy capacity and its centralized control. Client-based P2P networks are scalable but do not guarantee high quality streaming service due to the transient nature of peers. To address these limitations, we present a novel and efficient design of a scalable and reliable media proxy system supported by P2P networks. This system is called PROP abbreviated from our technical theme of “collaborating and coordinating PROxy and its P2P clients”. Our objective is to address both scalability and reliability issues of streaming media delivery in a cost effective way. In the PROP system, the clients' machines in an intranet are self-organized into a structured P2P system to provide a large media storage and to actively participate in the streaming media delivery, where the proxy is also embedded as an important member to ensure quality of streaming service. The coordination and collaboration in the system are efficiently conducted by our P2P management structure and replacement policies [8].


1)S. Acharya and B. Smith, “Middleman: A Video Caching Proxy Server,” Proc. ACM Int'l Workshop Network and Operating Systems Support for Digital Audio and Video, June 2000.

2)E. Bommaiah, K. Guo, M. Hofmann, and S. Paul, “Design and Implementation of a Caching System for Streaming Media over the Internet,” Proc. IEEE Real Time Technology and Applications Symp., May 2000.

3)L. Cherkasova and M. Gupta, “Characterizing Locality, Evolution, and Life Span of Accesses in Enterprise Media Server Workloads,” Proc. ACM Int'l Workshop Network and Operating Systems Support for Digital Audio and Video, pp. 33-42, May 2002.

4) M. Chesire, A. Wolman, G. Voelker, and H. Levy, “Measurement and Analysis of a Streaming Media Workload,” Proc. Third USENIX Symp. Internet Technologies and Systems, Mar. 2001.

5) B. Cohen, “Incentives Build Robustness in BitTorrent,” Proc. First Workshop the Economics of Peer-to-Peer Systems, June 2003.

6) Y. Cui and K. Nahrstedt, “Layered Peer-to-Peer Streaming,” Proc. ACM Int'l Workshop Network and Operating Systems Support for Digital Audio and Video, pp. 162-171, June 2003.

7) S. Gruber, J. Rexford, and A. Basso, “Protocol Considerations for a Prefix-Caching for Multimedia Streams,” Computer Network, vol. 33, nos. 1-6, pp. 657-668, June 2000.

8)L. Guo, S. Chen, S. Ren, X. Chen, and S. Jiang, “PROP: A Scalable and Reliable P2P Assisted Proxy Streaming System,” Proc. IEEE Int'l Conf. Distributed Computing Systems, pp. 778-786, Mar. 2004.