The Impact And Challenges Of The P2ptv

Published Date: 02 Nov 2017

INTRODUCTION

The thirst for online video services is tremendously increasing as high speed internet connections become common among the internet users. It is estimated that p2p file sharing has contribute to 70% of internet traffic which means that p2p is really a trending for this time being. There are two types of p2p file sharing which is p2p audio and also video streaming. Back in May 2010, YouTube announced that in one day, they have serve about more than two billion video on demand. Video on demand is the type of video that one can watch anytime they wish to watch. The client-server technology was widely known way of providing a live video. In this particular technology, a multiple clients are directly connected to a single server. When the maximum number of clients reaches its peak, the new client will be blocked from joining the session. Unicast and multicast are the two different ways in providing streaming video. In unicast, all users are directly connected to a single server. The benefit of using this kind of method is that in term of simplicity and it also can reduce the users start up delay. However, the server must have high bandwidth connection to withstand the work load and the cost to maintain the functionality of unicast system is quite high. Whereas, the principle of multicast is that all users on the video session connected to the video source server via a multicast tree formed by routers in the network. In this system, the routers in the network really play an important role as it is used to manage and to control the distribution and duplication of video data. Unfortunately, multicast is not widely deployed because it has technical complexity and other deployment issues. Therefore, a new form of multicast was introduced; overlay network. The most well-known overlay network is P2P (peer-to-peer) which is more scalable. It is the solution for inexpensive broadcast of real time video contents over the internet. Basically, p2ptv is a type of applications that offer the capability to watch real time video over the internet at low cost. Besides, they also offer the opportunity of reaching a potentially unlimited audience without expensive infrastructural investment to the content provider and broadcaster. P2ptv is actually a technology that user can receive streaming content and at the same time upload the same received content to other users. Each viewer will contribute to the overall capacity of available bandwidth. The general operation of p2ptv is that the p2ptv software/plug in will contact a tracker whenever a user joins certain channel. The tracker will register the address of peers who are watching and thus distribute the channel. Then, it will contact these peers to also receive parts of the fees from one or more users. The tracker will record the internet user’s address so that it can be informed to another user who wishes to watch the same channel. In addition, p2ptv applications are based on proprietary and unknown protocols that make the detection of the traffic challenging per se. The p2ptv systems have become part of the internet landscape. Proprietary is generally a receiver-driven, which means the particular receiver will search for the suitable peers so that he/she can download from and at the same time trying to maximize their performance. It will results in huge and non-optimized traffic loads.

Basically in file sharing p2p system (mesh based), the video content will be sliced into pieces. These pieces are called chunks; it will be distributed onto an overlay topology exploiting a fully distributed epidemic approach. Otherwise, chunks are generated in real time, which are sequentially and periodically. The peers must receive the chunks within a deadline to be played out, so that the key aspect of these systems is the timely delivery. That’s a bit explanation on how p2ptv system works.

Although some applications have become popular among internet users, the network operators are afraid of the large amount of traffic they might create and affecting other services. Also may cause network congestion and collapse. Network congestion is due to too much data being carried by the link or node that its quality of service deteriorates. Then, it will cause queuing delay, blocking of new connections and packet loss. Congestion collapse is a result of network congestion. The congestion collapse is actually a condition when no useful or a little communication occurring as a result of congestion that can be reached by the packet switched network. This situation occurs at choke points in the network where the total incoming traffic to a node exceeds the outgoing bandwidth. Choke points are connection points between a local area network (LAN) and a wide area network (WAN). Since there will be a bad impact, then a simulator is developed to understand the impact of these new services on network performance. A simple evaluation of p2ptv system is done in order to focus on their impact on the transport network. There are two types of different topologies which are the logical topology and also the physical network. The logical topology at the application level is made up by peers that is created and updated whenever a peer joins or leaves the network. The physical network is composed by hosts, node and links, which is typically given and rarely changes. Each peer will exchange the content with other peers whenever the logical connection is established. The graph which is created by peers is called overlay topology and underlay topology is made up by real devices such as routers and links. The other examples of impacts of p2ptv that can be observed are that the network broadcasters do not want the internet users to be able to watch the content that they paid for before the content is actually being broadcasted or being on aired. Besides that, the advertisement agencies need to adjust their strategies by knowing how many viewers and what kind of viewers are reached. But, as for a producer which is the content creator, they do not want their content available in high definition quality that can be viewed on computer system. Nowadays, many users record television broadcast on computer then convert it to suitable format and distribute to the net. Then, other users can download the file so easily.

There are challenges or issues that need to be considered. The major issues that need to be addressed are the increase in control traffic, but we can be alleviated by using tracker with a finer-grained view of peers and fully utilizing locality of peers. The best way to overcome this issue is to adopt an oracle server that is used to choose peers by looking at the local proximity and availability. The second major issue is it will lead to low efficiency of p2p for the not so well-known channels and also during low usage periods, where the role of video servers becomes critical. In addition, there a few challenges of p2p streaming that had been discovered. The first challenge is user experience that can lead to unexpected bill of bandwidth, affect other application and occupy disk space. Resource monitor, intelligent interference minimization algorithm and infrastructure support are the alternative way to tackle this challenge. It involves user activity detection, adaptive back-off algorithm and also deployed super nodes. Secondly, there might be delay. The delay of p2p system is still quite large because the delay occurs in pull-based system is about 10-20s while in push-based system is 5-8s. In order to overcome delay, a super nodes need to be exploited for more stable overlay. The last challenges that need to be considered are flash crowd. Flash crowd is fair common in streaming whenever big events such as Olympics or world cup take place. During this period, each peer wants to watch the play as soon as the play started. This kind of situation is not easy as in p2p file sharing because long delay is not acceptable. There is a capacity limit for system to sustain flash crowd. Then, the way to settle this challenge is by increasing the stable peers. Admission control is needed as it can increase the shock level and the capability nodes are high during first entry.

CONCLUSION

By doing this assignment, we had learnt the impacts of p2ptv traffic over the physical topology of a network and challenges of p2ptv. Even though the p2ptv application is now becoming very famous among users, but still it need to be in control in order to avoid potential congestion. Then a simulator is developed to efficiently study the traffic this application can inject in the network. It is possible to decrease the amount of traffic the network has to carry and at the same time improving the quality of service perceived by users. We also learnt that the p2ptv can affect the television industry even if the industry does not use p2ptv as a distribution method. P2ptv in television industry can lead to misuse of the technology as one cans easily re-distributing the content via internet using p2ptv network.

This encourages depth investigations as to ensure the level of p2ptv network awareness application to be increased. In my opinion, the development of p2ptv is actually something that is very good because people nowadays love watching streaming TV and enjoys their favorites TV episodes and shows. Due to time constrain and budget constraints, people from all over the world can easily download their desired content.