Algorithm Model and Performance Evaluation of P2P Network System under the Internet of Things

2017 2nd International Conference on Communications, Information Management and Network Security (CIMNS 2017) ISBN: 978-1-60595-498-1

Algorithm Model and Performance Evaluation of P2P Network System

under the Internet of Things

Yi-bin HOU

and Jin WANG

School of Software Engineering, Department of Information, Beijing University of Technology, Beijing, China

No. 100 Ping Park, Chaoyang District, Beijing, China

*Corresponding author

Keywords: Algorithm, P2P, Network system.

Abstract. With the development of computer technology and communication technology, network communication has brought great convenience to people. It has gradually become an indispensable part of people's daily life and work. The Internet is the largest computer network, and the rapid development of the Internet benefits from the emergence of client / server (Client/Server, C/S) network patterns. Client / server mode is the basic mode of traditional network, and also the most traditional and mature centralized mode of work in Internet. Many Internet application protocols (such as HTTP, FTP, SMTP, etc.) have adopted this mode. As the implementation of distributed computing technology is one of the forms of network P2P (Peer-to-Peer Network), because there is no centralized control, can avoid the server bottleneck problem of C/S network mode, and can meet the needs of users between the direct exchange of information, to achieve a free Internet environment.

Introduction

First, investigation of a mapping model of packet loss rate and the Quality of experience [1]. Second, Research on Packet loss rate mapped to the Quality of experience [2]. Third, Investigation of the influencing factors of network packet loss’s long-range dependence affect the packet loss rate and further the QoE [3]. Fourth, Investigation of the Packet loss rate mapped to the quality of experience [4]. Fifth, Investigation on the Internet of Things [5]. Sixth, Investigation on Mapping model of packet loss rate and the Quality of experience [6]. Seventh, Investigation at the QOE and Packet Loss Rate of the IOT Network [7]. Eighth, Investigation of the IOT Network of Packet Loss’ Long-Range Dependence and QOE [8]. Ninth, Investigation of the QOE forecast under the Distributed Internet of things [9]. Tenth, Investigation of the No-reference video quality assessment model considering the network packet loss based on Least squares support vector machine under the Internet of things [10]. 2lemetry is known as "the only leader to prove feasible, and can be any networking protocol and equipment interaction platform", can realize the multi-point and multi dimension, communication, the core is "Broker" level, which is P2P can make the whole platform more easily achieve the expansion, as long as every new equipment as a node joins the network, let IOT devices of different protocols together.

Methods

through the zlvircom tool, you can communicate through the virtual TCP port or virtual serial port method, and you can communicate via the LAN P2P development kit on your mobile phone.

The second kind, shown in Figure 3, is the N2N product, which is generally used for forwarding data from TCP server side network devices in LAN and realizing Internet transmission based on P2P. The utility model is especially suitable for monitoring the network port PLC.

Results

Although the study of MIT and UC Berkeley on the development of the Chord system and its application in early 2001 before, but the [Stoica et al. official Chord 2001], published in the field of computer communication famous conference, ACM SIGCOMM 01, and other publications have published the meeting later on the Chord, such as [Stoica et al., 2003]. The chord is the most famous theoretical model of structured P2P field, and has been cited more than 3000 times by 2006. It can be said that none of the people who have studied P2P do not know Chord. If you think of Chord as just a distributed hash table, it only supports the simplest function of structured P2P: mapping nodes and data objects into overlay networks. Chord allocates node ID and object ID based on a secure consistent hash function. In a N node in the network, each node maintains a Chord O (log N) other node information query, overlay network data objects need the number of hops is O (logN), when nodes join or leave the network, in order to maintain the network structure, keep the adaptive required number of messages in O (log2N). As a distributed hash table, Chord with almost optimal deterministic routing efficiency, object query, load balancing, high scalability and good fault tolerance and adaptability; but the most important point is: Chord simple, beautiful, it is the most classic direct causes. If the Chord as a P2P network, then it is a distributed system based on chord ring topology, data object storage, query, copy, cache, but also more high-level architecture of distributed data access systems such as CFS (cooperative file system on top of it, cooperative file system). The core of the chord is to provide a fast, distributed computing method that uses hash functions to locate key values to nodes that store the key. 1, the hash function can load equilibrium. 2, when the N node joins or leaves the network, only the O (1/n) keys needs to migrate to another node, which is the minimum cost required for load balancing. 3, in a chord network with n nodes, each node only needs to maintain the information of O (log (n)) nodes, which greatly improves scalability. N1 the process of finding node N53 as shown in figure 1.

N1

N18

N25 N26

N45 N53

Figure 1. N1 the process of finding node N53.

node n stores (n+2i-1) successor. The lookup is based on the recent principle that the current node does not store Key, and looks for the Node nearest to the hash (Key) from the Finger table to continue the process. Here is to distinguish between the Key of a successor or the successor of node n, and pay attention to the nearest matching principle. If the distance between the successor I and the Key in the Finger table of the node n is nearest, then it is satisfied: Key is in the middle of the item I and i+1, Remember item I is J and item i+1 is P, J<hash (Key), P>hash (Key). While: J = n + 2i-1, P = n + 2I

The distance between the node n and the Key should be between N and J and P, that is, J-n<n - hash, (Key) <P - n. (1) 2i-1<n - hash (Key) <2i. (2) the maximum distance between J and Key is J and P. The distance is J-hash (Key) <P - J = 2i-1. It is said that J and Key distance are less than N and Key distance, and the distance is less than half of the N and Key distance, so we guarantee that each iteration, the distance between a and Key will converge, and at least 2 exponential convergence, namely beseeches. So far, we theoretically prove the convergence of Chord.

Go deep into the Chord algorithm. In fact, the Chord algorithm can be completely transformed into a mathematical problem: On the Chord ring, arbitrarily mark the points as the Node set, arbitrarily specify Node T, from any Node N start, according to the Chord search algorithm can find the node T. Why can you change this way? Because, as long as the direct access to the Key is found, and even if the Key is found, all the problems are translated into a problem of finding Node through the Node on the Chord ring. So, this problem will immediately become very magical, if we find the step record as the path into a shortest path between any 2 nodes, while the Chord algorithm is constructed so that the shortest path, the path will not exist? No, because Chord it is a ring, the worst case can be guaranteed by linear search. From the point of view of the shortest path, Chord is only the improvement of the existing linear path. According to this idea, we can design other shortest path algorithms. From the view of algorithm originally premise, convergence or correctness of each Node is to maintain its successor node, but in a large P2P network, there will be frequent node joining and exiting, without additional work, it is difficult to ensure that each node has the correct successor.

Chord redundancy: Redundancy means that there is a garbage item in the Finger table of Chord, and the items between Node N and its successor are meaningless because the successor represented by these items does not exist. For example, in the N1 Finger table in first to 5 do not exist, they point to the N18, at least first ~ 4 for redundant information. Generally speaking, if the Chord ring size is 2m, 2n is the number of nodes, if nodes are evenly distributed on the Chord ring, then any node N in the Finger table in section I for redundant terms: N+2i-1<N + 2m/2n =>2i-1<2m-n =>I <m-n+1, when I <m-n+1 is redundant. Redundancy is: (m-n+1) /m=1- (n-1) /m, generally speaking m >>n, so Chord will have a lot of redundant information. If there are 1024 nodes on the network, namely n=10, is redundant: 1- (10-1) /160 = 94%. So many papers point out this, and think that it will cause redundancy query and reduce performance. In fact, because this redundant information is distributed in multiple Node Finger tables, if appropriate routing algorithm is adopted, the routing calculation will not have any impact [11]. Figure 2 is a schematic diagram of a Chord identification ring with three nodes. And Table 3 is a table of the fingers.

Part of the code: // ask node n to find the successor of id n. find_successor (id)

if (id belongs to (n, successor])

return successor; Else n0 = closest preceding node (id);

return n0. find_successor (id); // search the local table for the highest predecessor of id n. closest_preceding_node (id) for i = m downto 1

if (finger[i] belongs to (n, id)) return finger[i]; return n; Node Joins and Stabilization: Contains 6 functions:

(1) create (), (2) join (), (3) stabilize (), (4) notify (), (5) fix_fingers (), (6) check_predecessor (). n. create ()

predecessor = nil;

successor = m. find_successor (n); n. stabilize ()

x = successor. predecessor; if (x ((n, successor))

successor = x;

successor. notify (n); n. notify (m)

if (predecessor is nil or m ((predecessor, n)) predecessor = m;

n. fix_fingers () next = next + 1; if (next > m)

next = 1;

finger [next] = find_successor (n + 2next-1); n. check_predecessor ()

if (predecessor has failed) predecessor = nil;

0

1

2

3 4

5 6

7

6

1

2 Successo

r(6)=0

Successo r(1)=1 Successo

r(2)=3

0

1

2

3

4

5

6

7

Finger table 1

Finger table 2

Finger table 3

Figure 2. N1 the process of finding node N53.

Table 3. A Chord identification ring with three nodes.

Start. Finger table 1 keys

Int. Succ.

6

1 [1,2) 1

2 [2,4) 3

4 [4,0) 0

Start. Finger table 2 keys

Int. Succ.

1

2 [2,3) 3

3 [3,5) 3

5 [5,1) 0

Start. Finger table 3 keys

Int. Succ.

2

Start. Finger table 2 keys

Int. Succ. 1

5 [5,7) 0

7 [7,3) 0

Conclusions

A chord is a very good P2P algorithm. 1. Smart home applications. A smart Home Furnishing company, before using TCP server Home Furnishing intelligent gateway, although at home, users can access the intelligent mobile phone Home Furnishing gateway, but if the outdoor intelligent gateway access Home Furnishing is more trouble. 2. Mobile phone configuration software. A company uses mobile phone configuration software to monitor an agricultural Internet of things project, including the temperature of the agricultural greenhouse, control irrigation, etc. But this phone configuration software cannot access the Internet of things gateway via 3G/4G. At this time, the use of Zhuo LAN ZLAN5143N, connect various Modbus RTU instrument and controller. Run the mobile phone side P2P management software ZLP2pSDK on the phone, users can easily monitor the status of agricultural greenhouses anywhere. 3. PLC remote monitoring. The machinery produced by a mechanical plant is equipped with various PLC and touch screen, on which PLC and touch screen have both a network port and a serial port. In order to update the program remotely, the debugger often needs to send an engineer to the site for debugging. After installing ZLAN5143N, you can debug and upgrade serial port, PLC and serial port screen remotely. After you install ZLAN7144N2, you can remotely debug and upgrade the network screen. Save the trouble of business trip. The application of game theory and trust model and stochastic process in the Internet of things is the direction of the future.

Acknowledgement

Supported by the Beijing University of Technology and software college doctoral student scholarship and grants. Thanks to National Natural Science Foundation of China (No: 61203377, 60963011, 61162009). Thanks to Hou Yibin supervisor for my work, learning, research, life, all aspects of care and guidance and help, under his guidance, published a lot of ISTP, EI, SCI and IEEE papers. Hou Yibin supervisor’s domestic and International vision and a keen academic insight and a thorough understanding of Beijing and the Beijing University of Technology and society and team work spirit’ s work methods and selfless work attitude and painstaking and punctuality work style and cultivate students' moral lofty painstaking patience benefit for life. Hou teacher for my study devoted a great deal of effort, this inspiring mentor. Mr. Hou is humane, kind and approachable. I was in the evaluation network to Hou teacher sent flowers.

References

[1] Jin Wang. Mapping model of packet loss rate and the Quality of experience [J]. International Conference on Information Science and Intelligent Control, 2015.

[2] Jin Wang. Packet loss rate mapped to the Quality of experience[J]. International Conference On Information Science And Intelligent Control, 2015.

[3] Jin Wang. The influencing factors of network packet loss’s long-range dependence affect the packet loss rate and futher the QoE[J]. International Conference on Information Science and Intelligent Control, 2015.

[5] Wang, Jin, and Yi bin Hou. Investigation On The Internet Of Things[J]. International Journal of Engineering Sciences & Research Technology, IJESRT, 2016.

[6] Yi bin Hou. Jin Wang. Investigation on Mapping model of packet loss rate and the Quality of experience[J]. International Journal of Current Trends in Engineering & Technology, IJCTET, 2016.

[7] Yi bin Hou. Jin Wang. Investigation at the QOE and Packet Loss Rate of the IOT Network [J]. American Journal of Data Mining and Knowledge Discovery, 2017.

[8] Yi bin Hou. Jin Wang. Investigation of the IOT Network of Packet Loss’ Long-Range Dependence and QOE[J]. Machine Learning Research, 2017.

[9] Yi bin Hou. Jin Wang. QOE forecast under the Distributed Internet of things[J]. Advances in Cloud and Internet of Things, 2017.

[10] Yi Bin Hou, Jin Wang. No-reference video quality assessment model considering the network packet loss based on Least squares support vector machine under the Internet of things[C]. 14th IEEE International Conference on Advanced and Trusted Computing, IEEE ATC 2017 conference.