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Application of P2P Network


Peer-to-peer (P2P) is a kind of a network that is normally created when more than one P Cs are connected in such a way that they share resources without the aid of the separate computer server. This type of connection can be created in three different forms. Firstly, it can be in an ad hoc connection where a number of computers are connected through a universal serial bus in order to transfer files. The second type of connection can be through a permanent infrastructure, which connects half-dozen computers over copper wires in an office. The final connection can be over the internet using special protocols and applications. This connection is important since it can be applied over a larger grander.

Uses of peer-to-peer application

Peer-to-peer application has a come with a number of importance. Some of its uses include the following. First, this type of network allows computers configured with it to share a number of components including files and printers among others (Cope, 2002). On the other hand, peer-to-peer network is also used to ease the process of sharing data in either direction. For instance, peer network allows data to be downloaded or uploaded to and from a computer easily. Peer network is also used over the internet in handling high volume of files sharing the traffic. This is through dispensing the load across several computers. This network is also used in Skype for traffic routing, processing and bandwidth-intensive task thus replacing the central servers.

How peer-to-peer network works on Skype

The Skype just like Kaaza uses peer-to-peer network in order to function. For this application to take place there is the need of two nodes connected in overlay networks. These two nodes are the ordinary host and the super node (SN). Ordinary host is important since bit is through it that voice calls and text messages are sent in the Skype’s application. On the other hand, the super node is the device, which obtains a complete CPU, has sufficient memory, has an IP address and is connected to a bandwidth network for the purposes of receiving data from a variety of ordinary nodes. Super node also necessitates the sending and receiving of data to and from other Super nodes connected to it in the same Skype network.

However, for a Skype application to become complete there is also the need of a Skype log in the server. This log in the server is the device that enhances the exchange of message from the user to the ordinary nodes. In addition, the servers also help in authenticating and keeping of the passwords and user names. The other importance of the login server in the Skype application is that it prevents double entry of similar user name within the network. This is through maintaining the uniqueness of user names (Vangie, 2010). Therefore, the log in servers ensures that every user has a different user name and not even a single user name may resemble others

Figure illustrating how Skype network operatesApplication of P2P Network

Even though Skype has two other types of servers known as Skype in and Skype out, which help in the bridging of PC and PSTN, they are not considered part of the Skype P2P network. This is because the two servers are irrelevant in the establishment of inter-PC calls. Therefore, the only relevant server in the Skype’s P2P application is the login server.

Employment of overlay application in Skype peer-to-peer network

Overlay networks are those that are applied on top of the others. This statement therefore implies that a P2P overlay networks are application layers constructed by internet peers over the IP network. P2P overlay networks are therefore distributed in nature without any protocol organization or centralized control. It is therefore important to note that peer-to-peer overlay system surpasses the services offered by the client/server system in the sense that a client may perform the server’s role (Lua, Crowcroft, Pias, Sharma, & Lim, 2004, p. 2). The P2P overlay network system can therefore be viewed as a model, which spans wide spectrum of communication structure. This communication structure specifies a cooperative network design with peers thus building a system that is self-organized.

An overlay networking is therefore employed in Skype application of p2p network through incorporation of other variants such as the STUN protocol. This protocol helps the Skype node in determining the NAT it is situated (Baset, & Schulzrine, 2005). This factor therefore helps in explaining how an overlay network is employed in the Skype P2P network. Furthermore, each Skype client creates a table of reachable nodes, which is refreshed concurrently as the nodes keep changing within the Skype network. This factor therefore implies that it is through the aid of overlay network that each Skype clients becomes capable of creating its own HC. The other way through which overlay network is applied on the Skype P2P network is through implementation of ‘3G P2P” technology within the Skype network thus enabling another user within the network to discover one who has logged in.

Relationship of physical and overlay network in P2P application

From the initial discussion, it is clear that an overlay network is a layer of implicit network that is normally added on top of the physical network. This statement therefore implies that for an overlay network to exist there must be a physical network onto which it is going to be added on. Overlay networks therefore only provide the chance of utilizing the increasingly growing internet information and resources that has been availed with the help of physical network. A Skype application is a program that is available on the physical network and within it, some other software has been implemented and only functions within its network. For instance, the STUN protocol is one of the modern protocols that are channeled in the operating systems and has therefore ease the process of determining the existence of Nat and firewall within the global network (Lua, Crowcroft, Pias, Sharma, & Lim, 2004, p. 2).

The advantages of having an overlay application in P2P application

Overlay network has exhibited many advantages in peer-to-peer application. Among this advantages are as follows: First, overlay application enables networking developers and application users to design and implement personal communication location and procedure on top of the internet. This has been achieved through routing of data and management of file sharing. Secondly, overlay network has enhances flexibility in data routing through quick detection and avoidance of network congestion. This factor has also been influenced by the ability of overlay networks to adaptively select paths based on various metrics (Vangie, 2010).

Flexible routing factor in overlay networks has also improved its end-node connections. This has been so through the aid of a physical network connection, which enhances communication between end-nodes through overlay networks. This factor has influenced the overlay network to attain two attractive features, which are scalability and robustness (Lua, Crowcroft, Pias, Sharma, & Lim, 2004, p. 4). Eventually, overlay network has led to effective sharing of enormous information available on the internet. This is achieved through high connectivity of end-nodes hence the increased amount of end-nodes within the overlay network.


Baset, S. A., & Schulzrine, H. G. (2005 January 6). An Analysis of the Skype Peer-to-Peer Internet Telephony Protocol. Retrieved from

Cope, J. (2002 April 8). QuickStudy: Peer-to-Peer Network. Retrieved from

1-22.IEEE Communications Survey and Tutorials,Lua, E. K., Crowcroft, J., Pias, M., Sharma, R. & Lim, S. (2004). A Survey and Comparison of Peer-to-Peer Overlay Network Schemes.

Vangie, B. (2010 December 20). All about Peer-to-Peer (P2P) Networks. Retrieved from