CN107835129A - Content center network fringe node potential energy strengthens method for routing - Google Patents
Content center network fringe node potential energy strengthens method for routing Download PDFInfo
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Abstract
The present invention relates to a kind of content center network fringe node potential energy to strengthen method for routing, belongs to internet arena.The problem of cache contents cause router efficiency low can not be perceived for content center network, propose a kind of ENPER based on potential energy, establish the Potential Model of node, and by strengthening the potential energy of fringe node, interest bag is attracted into cache node nearby to be responded, to reach the forwarding time for reducing interest bag, the purpose of cache hit rate is improved；In addition, ENPER, by fringe node statistics and the popularity of predictive content, with reference to the size of network, the potential energy for distinguishing different popularity contents notices scope, to reach the purpose for reducing network overhead.The present invention significantly reduces the load of publisher's server and caching notice expense, the average request time delay of content reduces 43% than Best routing.
Description
Technical Field
The invention belongs to the field of Internet, and relates to a content center network edge node potential energy enhanced routing method.
Background
According to the predicted report of cisco vni, the traffic generated by the video-like application in 2021 will account for about 82% of the total network traffic. The need for mass-replication propagation of video content has led to the popularity and commercialization of Content Distribution Networks (CDNs) and peer-to-peer networks (P2P). Both of them improve the speed of the user accessing the content, but the CDN forwards the user request to the edge server of the network in a DNS redirection manner, and the location where the content is stored is limited; P2P generates a tracker for each content, which is less effective for delivery. Since both cannot get rid of the end-to-end forwarding mode based on the IP address, security accidents such as DDoS attack and the like are caused. Therefore, researchers have proposed a new future network architecture, information Centric Networking (ICN), that fundamentally solves the conflict between the current connection-oriented internet model and the rapidly increasing traffic demand. The ICN is identified by the name of the content rather than the assigned IP address, so that the request made by the user need only be concerned with the content itself, not with the location where the content is stored. Typical ICN architectures are DONA, puruit, CCN, COMET, PSIRP, where CCN (contentcentricnetwork) is considered one of the most promising schemes.
The CCN architecture adopts a naming mode similar to URL, provides service from an end to content, supports the function of expanding routing nodes, enables the router to have a traditional forwarding function and certain storage capacity, and aims to reduce the transmission time of a data packet in a network in a mode of 'storage and bandwidth exchange' and realize a distributed cache network which is more flexible than a CDN. However, in the conventional CCN routing mechanism, the advantages of such "distributed cache" are not well utilized, because the conventional routing mechanism can only implement routing of interest packets to publishers, and a large amount of nearby caches outside the path cannot be used by sensing, which results in a large amount of waste of bandwidth resources. Therefore, an efficient and reliable cache-aware routing mechanism needs to be designed to fully exploit the caching advantages of CCN.
For the mechanism of cache perception of CCN, the main solved problem can be summarized into two points: 1) How to discover cached content; 2) How to forward the interest package towards the nearest one of the content sources.
The existing cache-aware routing mechanisms can be divided into two categories, one is that a requester actively issues a message to detect the position of cache content: the existing literature provides a routing mechanism (NCE) for neighbor cache detection, and the scheme calculates the shortest path by using a distributed ant colony algorithm, so that the sensing of local cache can be realized. However, this solution does not explicitly indicate the depth of probing, which may cause excessive overhead when the network range is increased. The other type is that the cache node issues cached content information to the periphery, and after passive reception, the requester performs comprehensive judgment and selects an optimal path: the literature proposes a Potential energy based routing mechanism (CATT), which constructs a Permanent Potential Field (PPF) for a stable publisher node, and is implemented in a flooding notification manner similar to the conventional CCN; a Variable Potential Field (VPF) is constructed for a variable cache node, potential energy of content of a neighbor node is announced by adopting a fixed hop count, and an interest packet determines a forwarding port of a next hop according to the received minimum potential energy so as to acquire the latest content. However, the scheme does not distinguish the server performance of the cache node and the publisher node, so that the interest packet does not select the nearest cache node for routing, and the request time delay of the content is large; meanwhile, the CATT advertises all cached contents to surrounding nodes by the same hop count, which causes huge bandwidth overhead.
Since the main function of the CCN router is still to forward packets quickly, the limitation of the router caching function needs to be considered. In addition, in most real scenes, the routers in the core and the middle of the network do not generate content requests, and the interest packets are all from users near the edge of the network, so that the interest packets are attracted to the nearby cache nodes as much as possible by using the cache at the edge of the network, and the response speed of the content is improved.
Disclosure of Invention
In view of this, the present invention provides a routing method for enhancing potential energy of an edge node in a content centric network, and provides a routing mechanism for enhancing potential energy of an edge node.
In order to achieve the purpose, the invention provides the following technical scheme:
the method for enhancing the routing of the content center network edge node potential energy comprises the following steps:
s1: the interest packet reaches the cache node;
s2: the server sends a corresponding data packet according to the received interest packet and returns the data packet along the original path;
s3: establishing an Edge Node enhanced Routing (ENPER) Potential energy model;
s4: and diffusing the potential energy by utilizing a cache node content announcement mechanism.
Further, S1 specifically is:
when an interest packet reaches a certain node, a Content storage table (CS) is inquired according to the routing characteristics of a Content Central Network (CCN); if the relevant items are matched, returning the data packet directly; if the relevant entries are not matched, inquiring a Pending Interest Table (PIT);
if the PIT inquires that the prior interest packet requests the content, adding a request port into the PIT entry and waiting for the return of the data packet; if the corresponding matching item is not inquired in the PIT, adding a request entry in the PIT, and searching a Forwarding interface with the minimum potential value in a Forwarding Information Base (FIB) for Forwarding by the interest packet; if the query is not available in the FIB at the moment, discarding the interest packet;
further, the S2 specifically is:
after receiving the interest packet, the publisher server sends a corresponding data packet and returns the data packet along the original path; checking the PIT every time when one hop passes, and if a plurality of ports exist in the PIT, copying a data packet and sending the data packet to a plurality of requesters; the data packets are then stored in the CS and a node potential field within the autonomous domain is established.
Further, the S3 specifically is:
abstracting the network into an undirected graph, and when a new content k is generated, dividing all nodes in the network into content publisher nodes n p Cache node n c And node n without content cache i Obtaining superposed potential energy; s represents a node set of the cache content k:caching potential energy parameters of nodes Wherein, the first and the second end of the pipe are connected with each other,the value range of (1) is between 0 and 1; l is the size of the load of the router, when the request quantity of the interest packet is too large and the router can not meet the request, L is reduced,reducing the parameter value;for any number of cache node to publisher hops,caching nodes for edgesTo publisher server n p The number of hops in between; the closer the cache is to the edge of the network,the closer the value is to 1, the larger the absolute value of the potential energy is; the closer to the cache of the publisher is,value is more overThe smaller the absolute value of the potential energy is, closer to 0.
Further, the publisher node n p The potential energy calculating method comprises the following steps:
setting a publisher server as a long-term stable negative point charge to form a full network potential field in the autonomous domain; when the content is not changed, the full network potential field keeps a stable state; any node n in the network i Is received by the publisher n p Has an attractive force ofAnd calculating according to the hop count, the time delay or the link bandwidth between the two:
wherein the content of the first and second substances,the quality of the content is produced for the publisher,is a node n i To the publisher node n p A minimum number of hops in between; n is a symbol when n is p The calculation formula of the potential energy isWhen is n i The calculation formula of the potential energy is
Node n further away from the publisher as the number of hops increases i The smaller the potential energy attractive force is, i.e.The smaller.
Further, the cache node n c The potential energy calculation method comprises the following steps:
setting alpha as a cache node n c Content mass ratio coefficient of (2):
wherein the content of the first and second substances,the quality of the content is produced for the publisher,is a node n i To the publisher n p A constant between 0.1 and 0.3.
Further, the calculation method of the superimposed potential energy comprises the following steps:
wherein the content of the first and second substances,the quality of the content is produced for the publisher,is a node n i To the publisher node n p A is a constant between 0.1 and 0.3.
Further, the S4 specifically is:
the content popularity of a CCN network is calculated according to the number of requests for content, assuming that a k content is at a requesting node n i The number of interest packet requests received in the last certain time period T isThe popularity of the content is defined as:
wherein K represents the content type of the cache node,indicating the arrival of n within a T period i Total number of requests; and correcting the popularity by adopting a simple prediction mechanism, wherein sigma is a prediction weight:
P T+1 (k)＝σP T (k)+(1-σ)P T-1 (k)
when the content of k is requested for the first time, the edge node collects the total number of requests of the downstream and informs the popularity of the content of k at the upstream node while sending an interest packet to the upstream; after the content returns and the potential field is established, the edge nodes continue to count in the time period of the period T, and inform the upstream cache nodes of the change of the popularity of the content, so that the real-time performance of the popularity of the upstream is maintained, and the uniformity of the same content announcement range is ensured.
Further, the announcement scope satisfies:
when P is present T+1 (k) If the number of hops in the advertising range is less than H1, the node does not advertise the content, and if the number of hops in the advertising range is less than 0, the node does not advertise the content;
when Hm is less than P T+1 (k) When the number of hops in the annunciation range is m < Hm +1, the annunciation is carried out on the range of m hops around, m is the threshold number of the potential energy annunciation normal hops, and m =2,3,4 \8230; n is the threshold number of maximum potential energy announcement hop count;
when P is present T+1 (k) When Hn is higher, the hop count of the notification range is n, namely the notification is carried out on the nodes in the n-hop range around;
wherein, H1, H2, \ 8230, hn is a jump threshold value, H1< H2< \ 8230, hn; hm is the threshold and k is the name of the requested content.
The invention has the beneficial effects that:
1) On the basis of potential energy concept proposed by the existing literature, a routing mechanism for enhancing the potential energy of an edge node is proposed aiming at the problem that an interest packet in a CCN comes from a network edge but cannot obtain a quick response at the edge node.
2) And providing an announcement mechanism for predicting the popularity of the content at an edge node and carrying out different hop counts on the potential energy value of the cached content by combining the size of the network topological range.
Drawings
In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:
FIG. 1 illustrates a forwarding process of the NPER;
FIG. 2 is a potential energy overlay of a cache node;
FIG. 3 is a potential field diagram of a topology and cache nodes of a network;
FIG. 4 is a graph of average request delay as a function of simulation time;
FIG. 5 is a graph of average request delay versus Zipf;
FIG. 6 is a graph of publisher server load reduction rate versus Zipf variation;
fig. 7 shows the trend of the cache advertisement overhead with Zipf.
Detailed Description
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In the CCN routing mechanism, when a publisher generates a new content, the publisher advertises the nodes of the whole network in a flooding manner, and an interest packet looks up an optimal path to the publisher based on a Forwarding Information table (FIB). For each router, only the next-hop port to the content publisher node is included in the FIB, but not to the nearby cache node. The average request delay of the traditional CCN routing mechanism is large because of the inability to sense the large amount of cache resources present in the network. On the basis of a potential energy concept proposed by scholars such as Suyong Eum and the like, the invention redesigns a cache-sensible edge node enhanced routing mechanism. Under the model, a publisher or a cache object is taken as negative point charge, and an interest packet, namely probe charge with positive charge, is forwarded along the direction with the fastest gradient decline and the smallest potential energy.
Fig. 1 shows a forwarding process of an interest packet when the interest packet passes through a cache node. When an interest packet reaches a certain node, firstly inquiring a Content storage table (CS) according to the routing characteristics of the CCN, and directly returning a data packet if the Content storage table is matched with a related entry; querying a Pending Interest Table (PIT) if no matching item exists, (1) if the prior Interest packet is queried in the PIT to request the content, adding a request port into a PIT entry, and waiting for the return of a data packet; and (3) if the PIT does not have a corresponding matching item, performing step (2) to add a request entry in the PIT, and then (3) the interest packet looks up the forwarding interface with the minimum potential value in the FIB for forwarding. If not queried in the FIB at this time, (4) the packet of interest will be discarded.
After receiving the interest packet, the publisher server sends a corresponding data packet and returns the data packet along the original path. After each hop is passed, (5) checking the PIT, copying a data packet to send to a plurality of requesters if a plurality of ports exist in the PIT, (6) storing the data packet in the CS, and establishing a node potential field in the autonomous domain.
1.ENPER potential energy model establishment
Firstly, abstract the network into undirected graph, when a new content k is generated, all nodes in the network can be divided into three types, namely a content publisher node n p Caching node n c And node n without content cache i And S represents a node set of the cache content k:
1.1 potential energy of publisher nodes
The publisher server is a source of content generation, has a large output rate, high processing performance and long-time storage capacity, and is set as a long-term stable negative point charge to form a full potential field in the autonomous domain. The full potential field, once established, will remain stable unless the content changes, and need not be updated as often. Network middle renMeaning node n i Is received by the publisher n p Has an attractive force ofThe value is calculated according to the distance between the two, and the distance can be hop count, time delay, link bandwidth and the like.
Wherein the content of the first and second substances,the negative sign of equation (1) ensures that interest packets are routed towards the lowest point of the potential field, for the quality of the content produced by the publisher, the size being related to factors such as the cache capacity of the server, the processing speed, etc.Is defined as a node n i To n p The node n which is farther from the publisher as the hop count increases i The smaller the potential energy attractive force is, i.e.The smaller.
1.2 caching potential energy of nodes
Although the route forwarding node in the CCN network has a caching capability, compared with the publisher, the main function of the router is to forward the data packet at a line speed, and the caching capacity and the processing performance of the router are far lower than those of the publisher server which provides contents for the local domain. In particular, when the cache is exhausted, a part of the content is deleted according to the replacement algorithm set by the CCN, so that the subsequent interest packet cannot be hit. According to this characteristic, α is set to the cache node n c Content mass ratio coefficient of (2):
since the requests for content of the current internet conform to a power law distribution characteristic (Zipf or mantelbrot-Zipf distribution), that is, 80% of the requests are only related to 20% of the content. For example, when the total number of contents in the network is N =1000,zipf =1.0, the request accumulation probability of the first 129 contents has reached 0.8, and the other Zipf distribution indexes are shown in table 1 in relation to the number of contents when the accumulation probability reaches 0.8. According to the above analysis, in order to enable the cache node to store the content with the largest request amount as possible, and considering the performance and cost of the routing node, α is set to be a constant between 0.1 and 0.3.
TABLE 1 relationship between Zipf distribution index and the number of contents when the request accumulation reaches 0.8
1.3 superposition of potential energy
Since the data packets are stored in the route nodes in the return, when a plurality of cache contents and contents generated by a publisher exist in the network at the same time, the total potential field is presented in a linear superposition manner, as follows:
it can be inferred from the above equation that when there are multiple cached contents, the potential energy near the publisher is larger than that of the copy node near the edge by way of mutual superposition, as shown in fig. 2 (a). However, in most practical scenarios, the interest packets come from users near the edge network, and the routers in the core and middle of the network do not generate requests; if interest packets from the edge are attracted by the network core and forwarded to the publisher server, cache contents closer to the edge will be missed, resulting in an increase in user request delay. Therefore, the potential energy value of the cache at the edge of the reinforcing network is considered, as shown in the right part of fig. 2 (b). The reasons are two reasons: 1) The interest packets from the edge are directly hit on the edge node, so that the request time delay can be reduced; 2) The requests of the edge cache nodes for collecting the same interest packets for multiple times in a centralized manner increase the residence time of the content, improve the availability of the target cache content and further increase the cache hit rate.
Fig. 3 shows a potential field diagram of the topology of a content-centric network. When a new content k is generated in the network, the publisher first advertises its flood to all routers within the autonomous domain and establishes a routing entry in the router's FIB to the publisher. Assuming that the PC1 firstly sends out an interest packet requesting the content of k, because nodes in the network do not have the cache content at the moment, the routing node calculates the shortest path according to the FIB and forwards the interest packet to the publisher, and the responding data packet returns the request path of the previous interest packet to the PC1 hop by hop and establishes a potential field. The cache here adopts a CCN default scheme CCE (cache updating every), that is, the content k is stored in all nodes passing by the return path,when PC2 issues the same interest package request k, it will be paired on RAAndand judging the potential energy value of the issued cache content. Setting up the publisherThe content quality proportion coefficient of the cache node is alpha =0.1, and when the network does not adopt an edge node potential energy strengthening mechanism, the content quality proportion coefficient is received on RAThe potential energy released isReceive fromThe potential energy released isDue to the fact thatThe next hop of the interest packet is RB, moving towards the one with less potential energyForwarding, not in the nearestAnd (4) hitting.
According to the above analysis, in order to ensure that the interest packet can be attracted by the edge cache potential energy to route towards the nearest cache, the potential energy parameter of the cache node is providedAnd under the condition of considering the node load, improving the potential value of the edge cache.
Is in the range of 0 to 1. Wherein, L is the size of the load of the router, when the request quantity of the interest packet is too large and the router can not meet the request, L is reduced,the parameter value is decreased.For any number of cache node to publisher hops,caching nodes for edgesTo publisher server n p The number of hops in between. The closer the cache is to the edge of the network,the closer the value is to 1, the larger the absolute value of the potential energy is; the closer to the cache of the publisher is,the closer the value is to 0, the smaller the absolute value of the potential energy. The same publisher as in FIG. 3The content quality proportion coefficient alpha =0.1 of the cache node, the router can meet the request requirement, namely when L =1, the potential energy of the edge node is enhanced, and the mixed potential energy value received by the interest packet sent to the RA is Since at this timeAfter the interest packages are compared, the interest packages face the direction of lower potential energy and fewer hopsAnd (4) forwarding.
2. Cache node content advertisement mechanism
After the model of the node potential field is established, if an advertisement mechanism is lacked to diffuse out potential energy, the potential field-based routing mechanism is not different from the traditional CCN routing mechanism: the interest packet will hit randomly on the forwarding path, and the adjacent cache node is missed. Therefore an announcement mechanism needs to be added to achieve attraction of the potential field. However, if all the cached content is advertised to the whole network, not only a large amount of overhead of the network is caused, but also when the cached content is replaced according to different algorithms, NACK advertisement needs to be issued to surrounding nodes to delete corresponding FIB entries, which also occupies a large amount of bandwidth resources. Therefore, a simple and efficient popularity determination mechanism and an advertisement range mechanism adapting to the network topology are needed to implement potential energy based routing.
2.1 computation and prediction of popularity of advertised content
In the existing literature, content is divided into three classes according to content requests in a power law distribution feature: popular, ordinary and cold, according to which the cached content is distinguished and announced, but the scheme is established by knowing the number of requests and the overall popularity of all the content in advance, and cannot be realized under the real network condition. In addition, the requested number of interest packets also has "convergence", and when a node receives a large number of identical interest packets, it records the downstream request port and adds it in the PIT, and then sends out only one interest packet upstream, so a way similar to the way of counting the number of interest packets received by the upstream node, or all nodes in the domain proposed in the literature, is also not desirable. According to the above analysis, the popularity value of the content can be counted and calculated only at the edge node. The edge-enhanced potential energy scheme provided by the invention can attract interest packets with the same request to an edge cache node as much as possible under the condition of considering node load, so that more accurate content popularity is obtained.
The content popularity of a CCN network is calculated according to the number of requests for content, assuming that a k content is at a requesting node n i The number of interest packet requests received in the last certain time period T isThen the popularity of the content is defined as:
wherein K represents the content type of the cache node,indicating the arrival of n within a period of time T i Total number of requests. Since a period of time elapses from the hit of the interest packet to the issuance of the notification to the surrounding nodes, and the popularity may change in this period of time, the popularity needs to be corrected by a simple prediction mechanism, where σ is the prediction weight:
P T+1 (k)＝σP T (k)+(1-σ)P T-1 (k) (6)
when the content of k is requested for the first time, the edge node will collect the total number of requests downstream and inform the upstream node of the popularity of the content of k while sending an interest packet upstream. After the content returns and the potential field is established, the edge nodes continue to count in the period T, and inform the upstream cache nodes of the change of the content popularity, so that the real-time performance of the upstream popularity is maintained, and the uniformity of the same content informing range is ensured.
2.2 setting of Notification Range of cache nodes
As can be seen from the above section, when the expected popularity is larger, the number of representative requests is larger, the stability of the cached content is higher, and the wide-range notification thereof can improve the availability of the content. The maximum range n-hop setting of the advertising node needs to depend on a specific network topology and size, and needs to meet the following requirements: 1) The advertised scope is limited within a domain; 2) The control flow generated by the duplicate notification is limited to a certain extent; 3) The choice of n should be less than the number of hops between the caching node to the publisher.
Table 2 cache advertisement scope
Therefore, the invention sets the hop threshold value according to the size of the network to realize the cache announcement aiming at different popularity contents, and the threshold value is H1, H2, \ 8230, hn (H1)<H2<…<, hn). When P is present T+1 (k)&H1, the node does not advertise the content, and when P is T+1 (k)&When Hn, it will announce to the nodes in the range of n hops around, when Hm<P T+1 (k)&When it is Hm +1, it will announce to the m jump range around, where 0<k<n。
3. Experimental setup
In this embodiment, an open-source simulation platform ndnSim is used to implement the Routing mechanism, and the CATT and the Best-Routing that is a mainstream on the simulation platform are compared. And the ndnSim is a simulation tool based on NS-3, and an NDN protocol stack is added on the platform, so that a routing mechanism of the CCN network can be realized. The total number of nodes in the experiment is 30, and the request arrival obeys Poisson distribution. The distribution of the requests of the users is furthermore adjusted according to the exponential distribution of Zipf. The Zipf index represents the concentration of requested contents, and the larger the index is, the more similar the requested contents are, and the smaller the index is, the more dispersed the requested contents are. The simulation time was 180s, and the other parameters are shown in table 3:
table 3 experimental parameter settings
3.1 Performance evaluation index
In order to objectively reflect the actual effects of different routing mechanisms and the influence of different parameters on the routing mechanisms, the following performance evaluation indexes are defined in the embodiment.
1) Average request latency
The request delay of a single content refers to the time from the beginning of sending the interest packet to the whole process of receiving the data packet, and the average request delay refers to the average value of all the request delay of the content in the range with the period T (set as 20s here). The average request delay reflects the average time from the request sending to the response sending of the user, and the smaller the value, the shorter the waiting time is represented, and the better the user experience is.
2) Publisher Server Load Reduction Rate (Load Reduction Ratio)
Wherein S _ counts represents the number of responses of the publisher server, and R _ counts represents the total number of requests of the user. The reduction rate of the server load represents that the load of the publisher is reduced due to the response of the distributed caches in the network, and the higher the index is, the more obvious the effect of the caches in the network is.
3) Cache advertisement Message Overhead (Overhead of cache Notification Message)
The cache announcement overhead defines the product of the length of each cache announcement message and the transmission distance in unit time, and sums the number of the announcement contents, wherein the size mainly depends on the length of the message, the announcement number of the message and the hop count. The larger the value, the more overhead the cache advertisement takes, and the more bandwidth it occupies.
3.2 simulation results and analysis
Setting simulation conditions that the cache announcement of the CATT is 2 hops, the maximum announcement range of ENPER is 3 hops, and Zipf =1. In the initial stage of simulation, because all routing nodes in the network have no storage, interest packets of different routing mechanisms must reach the publisher server to acquire contents, the request time delay in the initial stage is equal and larger, the hop count of the acquired contents is reduced along with the gradual increase of the cached contents in the network, the average time delay is gradually reduced, and finally the contents tend to be stable. Through comparative analysis, the average request time delay of the three routing mechanisms is Best-routing, CATT and ENPER from large to small. The specific reasons are as follows: in the FIB of Best-routing, only the shortest path to the publisher exists, and the content of the cache node outside the path cannot be sensed, so that most interest packets need to pass through the whole network to reach the publisher, the occupied link resources are the most, and the average request time is the longest; the CATT adopts a potential energy-based cache perception routing mechanism, compared with Best-routing, the method can enable the interest packet to be routed towards the cache node, and the average request delay is reduced; the ENPER attracts the interest packet to the nearest cache node hit by increasing the potential value of the edge node, the hop count is minimum, and the occupied resources are minimum.
According to the simulation result of fig. 4, it can be analyzed that the data fluctuation is large at the initial stage of the simulation, and the data is the simulation preheating time, so that the stable data between 100 seconds and 180 seconds is taken for the subsequent comparison to be analyzed. Since the index distribution of Zipf has a certain difference in different network scenarios, the difference of the three routes is compared by changing the distribution parameter (0.7-1.1) of Zipf. As shown in fig. 5, as the Zipf parameter increases, the average delay of three requests is continuously reduced, because the smaller the Zipf distribution index is, the more discrete the request content is, the diversified content request will cause the limited storage space to be replaced with high frequency, and the cache utilization rate is low; with the increase of the Zipf distribution index, the locality and concentration of the request content are continuously enhanced, the content stored by the CS is stable, the interest packet can hit the content in the cache node, and the average request delay is continuously reduced. Comparative analysis can show that when Zipf =1, average request latency of ENPER is reduced by about 43% compared to Best-routing and 17% compared to CATT.
Fig. 6 analyzes the impact of the Zipf distribution index on publisher server load. A higher publisher load reduction rate indicates that the interest package may have more content requested on the caching nodes in the network. The best performance of the comparison of the three is ENPER. When Zipf =1, the ENPER routing mechanism can reduce the load of the publisher server by 83%, because the interest packet can get the requested content at the edge node without reaching the publisher by changing the potential energy of the node. As the Zipf index increases, the rate of increase of the value corresponding to the ordinate is slowed down because the cache mechanism adopted is LRU, that is, when the router cache is full, the least recently requested content is eliminated. When the requests are gradually concentrated and the buffer capacity size is kept constant, the growth trend is slow.
Fig. 7 analyzes the relationship between the cache advertisement overhead and the Zipf exponential distribution. Compared with the prior art, the advertising cost of ENPER is lower because the CATT can diffuse the contents of all cache nodes to the surrounding nodes in a fixed hop count mode within a period time, and does not distinguish non-popular contents with few request times, and the blind advertising mode wastes bandwidth resources. Because the potential energy of the edge cache node is increased by the ENPER, the interest packets can be hit on the edge node through the attraction of the potential energy, and the number of the interest packets can be collected in a centralized manner at the edge node, so that the request distribution of a user can be better counted, and the PIT filtering effect existing in an upstream node can be reduced. In addition, ENPER sets the announcement range according to the prediction value of popularity, and a large amount of non-popular content cannot send announcement messages to surrounding nodes, so that the availability of the content is improved, and the announcement overhead is reduced.
In order to realize the nearby response of the request content and improve the utilization rate of cache resources, potential energy models are constructed for cache nodes and publisher nodes of a content center network, and a routing mechanism ENPER with edge node potential energy enhancement is provided on the basis. By changing the potential value of the node close to the edge, the attraction of the edge cache content is increased, the interest packet is attracted to the nearby node to quickly hit and respond, and the average request delay of the content and the load of a publisher server are reduced; meanwhile, the predicted popularity of the content is calculated at the edge node, the range announcement of the content with less quantity and high popularity is expanded, the announcement of the content with more quantity and low popularity is reduced or not sent, and the consumption of the announcement message on the network bandwidth is reduced.
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.
Claims (9)
1. The method for enhancing routing potential energy of the edge node of the content center network is characterized by comprising the following steps: the method comprises the following steps:
s1: the interest packet reaches the cache node;
s2: the server sends a corresponding data packet according to the received interest packet and returns the data packet along the original path;
s3: establishing an Edge Node enhanced Routing (ENPER) Potential energy model;
s4: and diffusing the potential energy by utilizing a cache node content announcement mechanism.
2. The content centric network edge node potential energy enhanced routing method of claim 1, wherein: the S1 specifically comprises the following steps:
when an interest packet reaches a certain node, querying a Content storage table (Content Store, CS) according to the routing characteristics of a Content Central Network (CCN); if the relevant items are matched, returning the data packet directly; if the relevant entries are not matched, inquiring a Pending Interest Table (PIT);
if the PIT inquires that the prior interest packet requests the content, adding a request port into a PIT entry and waiting for the return of a data packet; if the corresponding matching item is not inquired in the PIT, adding a request entry in the PIT, and searching a Forwarding interface with the minimum potential value in a Forwarding Information Base (FIB) for Forwarding by the interest packet; if not queried in the FIB at this time, the interest packet is discarded.
3. The content centric network edge node potential energy enhanced routing method of claim 1, wherein: the S2 specifically comprises the following steps:
after receiving the interest packet, the publisher server sends a corresponding data packet and returns the data packet along the original path; checking the PIT every time when one hop passes, and if a plurality of ports exist in the PIT, copying a data packet and sending the data packet to a plurality of requesters; the data packets are then stored in the CS and a node potential field within the autonomous domain is established.
4. The content centric network edge node potential energy enhanced routing method of claim 1, wherein: the S3 specifically comprises the following steps:
abstracting the network into an undirected graph, and when a new content k is generated, dividing all nodes in the network into content publisher nodes n p Cache node n c And node n without content cache i Obtaining superposed potential energy; s represents a node set of the cache content k:caching potential energy parameters of nodes Wherein the content of the first and second substances,the value range of (1) is between 0 and 1; l is the size of the load of the router, when the request quantity of the interest packet is too large and the router can not meet the request, L is reduced,reducing the parameter value;for any number of cache node hops to the publisher,caching nodes for edgesTo publisher server n p The number of hops in between; the closer to the cache at the edge of the network,the closer the value is to 1, the larger the absolute value of the potential energy is; the closer to the cache of the publisher is,the closer the value is to 0, the smaller the absolute value of the potential energy.
5. The content centric network edge node potential energy enhanced routing method of claim 4, wherein: the publisher node n p The potential energy calculation method comprises the following steps:
setting a publisher server as a long-term stable negative point charge to form a full-network potential field in the autonomous domain; when the content is not changed, the full network potential field keeps a stable state; any node n in the network i Is received by the publisher n p Has an attractive force of And calculating according to the hop count, the time delay or the link bandwidth between the two:
wherein the content of the first and second substances,the quality of the content is produced for the publisher,is a node n i To the publisher node n p A minimum number of hops in between; n is a symbol when n is p The calculation formula of the potential energy isWhen is n i The calculation formula of the potential energy is
As the number of hops increases, nodes ni that are farther away from the publisher are less likely to receive potential energy, i.e., the potential energy is less attractiveThe smaller.
6. The content centric network edge node potential energy enhanced routing method of claim 1, wherein: the cache node n c The potential energy calculation method comprises the following steps:
setting alpha as a cache node n c Content mass ratio coefficient of (2):
wherein, the first and the second end of the pipe are connected with each other,the quality of the content is produced for the publisher,is a node n i To the publisher n p A constant between 0.1 and 0.3.
7. The content centric network edge node potential energy enhanced routing method of claim 1, wherein: the calculation method of the superposed potential energy comprises the following steps:
wherein the content of the first and second substances,the quality of the content is produced for the publisher,is a node n i To the publisher node n p The minimum number of hops between them,α is a constant between 0.1 and 0.3 for the cache content node.
8. The content centric network edge node potential energy enhanced routing method of claim 1, wherein: the S4 specifically comprises the following steps:
the content popularity of a CCN network is calculated according to the number of requests for content, assuming that a k content is at a requesting node n i The number of the requests of the interest package received in the last certain time period T isThe popularity of the content is defined as:
wherein K represents the content category of the cache node,indicating the arrival of n within a T period i Total number of requests; and correcting the popularity by adopting a simple prediction mechanism, wherein sigma is a prediction weight:
P T+1 (k)＝σP T (k)+(1-σ)P T-1 (k)
when the content of k is requested for the first time, the edge node collects the total number of requests of the downstream and informs the popularity of the content of k at the upstream node while sending an interest packet to the upstream; after the content returns and the potential field is established, the edge nodes continue to count in the time period of the period T, and inform the upstream cache nodes of the change of the popularity of the content, so that the real-time performance of the popularity of the upstream is maintained, and the uniformity of the same content announcement range is ensured.
9. The content centric network edge node potential energy enhanced routing method of claim 8, wherein: the announcement range satisfies:
when P is present T+1 (k) If the number of hops in the advertising range is less than H1, the node does not advertise the content;
when Hm is less than P T+1 (k) When the number of hops in the annunciation range is m < Hm +1, the annunciation is carried out on the range of m hops around, m is the threshold number of the potential energy annunciation normal hops, and m =2,3,4 \8230; n is the threshold number of maximum potential energy announcement hop count;
when P is T+1 (k) When the number of hops in the notification range is n, notifying nodes in the n-hop range around the notification range;
wherein, H1, H2, \8230, hn is a jump threshold value, H1< H2< \8230, hn; hm is the threshold and k is the name of the requested content.
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108449608A (en) * | 2018-04-02 | 2018-08-24 | 西南交通大学 | The double-deck cache structure, corresponding blocks download protocol and the application in video cache |
| CN108769252A (en) * | 2018-06-21 | 2018-11-06 | 河南科技大学 | A kind of ICN network pre-cache methods based on request content relevance |
| CN108881943A (en) * | 2018-06-07 | 2018-11-23 | 南京邮电大学 | Based on the nodal cache replacement method of superseded index in P2P demand stream media system |
| CN109302348A (en) * | 2018-09-03 | 2019-02-01 | 中国联合网络通信集团有限公司 | A kind of data processing method based on CNN network and a kind of router |
| CN109981460A (en) * | 2019-03-19 | 2019-07-05 | 北京邮电大学 | A kind of service-oriented converged network, calculating, storage integral method and device |
| CN110213315A (en) * | 2018-05-30 | 2019-09-06 | 腾讯科技（深圳）有限公司 | A kind of determining method of path and device |
| CN110365801A (en) * | 2019-08-26 | 2019-10-22 | 陕西师范大学 | Based on the cooperation caching method of subregion in information centre's network |
| CN111404972A (en) * | 2019-01-02 | 2020-07-10 | ***通信有限公司研究院 | Data processing method, device, equipment and storage medium |
| CN111556514A (en) * | 2020-04-14 | 2020-08-18 | 北京航空航天大学 | Decentralized mobile edge computing resource discovery and selection method and system |
| CN112579301A (en) * | 2020-12-28 | 2021-03-30 | 北京理工大学 | NDN-based data transmission method for P2P distributed machine learning training system |
| CN113382053A (en) * | 2021-04-23 | 2021-09-10 | 河南科技大学 | Content active pushing method based on node semi-local centrality and content popularity |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710895A (en) * | 2009-11-30 | 2010-05-19 | 中国人民解放军信息工程大学 | Method for obtaining multiple next hop routing, device and router |
| CN105657054A (en) * | 2016-03-04 | 2016-06-08 | 重庆大学 | Content center network caching method based on K means algorithm |
| CN106028057A (en) * | 2016-05-05 | 2016-10-12 | 北京邮电大学 | Caching method for adaptive streaming content of scalable coding in mobile CCN (Content-Centric Network) |
| WO2016170559A1 (en) * | 2015-04-23 | 2016-10-27 | Nec Corporation | Method and system for bandwidth reservation for multiple tree based traffic engineering in content centric networks |
| CN106657181A (en) * | 2015-10-30 | 2017-05-10 | 中国科学院声学研究所 | CCN (Content center network) based data push method |
| CN106850436A (en) * | 2017-01-10 | 2017-06-13 | 中国矿业大学 | Mine hybrid wireless mesh network routing protocols based on virtual potential energy field |
-
2017
- 2017-10-24 CN CN201711002678.3A patent/CN107835129B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101710895A (en) * | 2009-11-30 | 2010-05-19 | 中国人民解放军信息工程大学 | Method for obtaining multiple next hop routing, device and router |
| WO2016170559A1 (en) * | 2015-04-23 | 2016-10-27 | Nec Corporation | Method and system for bandwidth reservation for multiple tree based traffic engineering in content centric networks |
| CN106657181A (en) * | 2015-10-30 | 2017-05-10 | 中国科学院声学研究所 | CCN (Content center network) based data push method |
| CN105657054A (en) * | 2016-03-04 | 2016-06-08 | 重庆大学 | Content center network caching method based on K means algorithm |
| CN106028057A (en) * | 2016-05-05 | 2016-10-12 | 北京邮电大学 | Caching method for adaptive streaming content of scalable coding in mobile CCN (Content-Centric Network) |
| CN106850436A (en) * | 2017-01-10 | 2017-06-13 | 中国矿业大学 | Mine hybrid wireless mesh network routing protocols based on virtual potential energy field |
Non-Patent Citations (3)
| Title |
|---|
| VASILIS SOURLAS ET AL: "Replication management and cache-aware routing in information-centric networks", 《2014 IEEE NETWORK OPERATIONS AND MANAGEMENT SYMPOSIUM (NOMS)》 * |
| 葛国栋等: "内容中心网络中基于差异化缓存通告的混合路由机制", 《电子与信息学报》 * |
| 赵炯: "内容中心网络兴趣包泛洪攻击理论分析模型研究", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108449608A (en) * | 2018-04-02 | 2018-08-24 | 西南交通大学 | The double-deck cache structure, corresponding blocks download protocol and the application in video cache |
| CN110213315A (en) * | 2018-05-30 | 2019-09-06 | 腾讯科技（深圳）有限公司 | A kind of determining method of path and device |
| CN108881943B (en) * | 2018-06-07 | 2020-08-14 | 南京邮电大学 | Node cache replacement method based on elimination index in P2P streaming media on-demand system |
| CN108881943A (en) * | 2018-06-07 | 2018-11-23 | 南京邮电大学 | Based on the nodal cache replacement method of superseded index in P2P demand stream media system |
| CN108769252A (en) * | 2018-06-21 | 2018-11-06 | 河南科技大学 | A kind of ICN network pre-cache methods based on request content relevance |
| CN109302348A (en) * | 2018-09-03 | 2019-02-01 | 中国联合网络通信集团有限公司 | A kind of data processing method based on CNN network and a kind of router |
| CN109302348B (en) * | 2018-09-03 | 2021-08-31 | 中国联合网络通信集团有限公司 | Data processing method based on CNN network and router |
| CN111404972A (en) * | 2019-01-02 | 2020-07-10 | ***通信有限公司研究院 | Data processing method, device, equipment and storage medium |
| CN109981460A (en) * | 2019-03-19 | 2019-07-05 | 北京邮电大学 | A kind of service-oriented converged network, calculating, storage integral method and device |
| CN110365801A (en) * | 2019-08-26 | 2019-10-22 | 陕西师范大学 | Based on the cooperation caching method of subregion in information centre's network |
| CN110365801B (en) * | 2019-08-26 | 2021-12-17 | 陕西师范大学 | Partition-based cooperative caching method in information center network |
| CN111556514A (en) * | 2020-04-14 | 2020-08-18 | 北京航空航天大学 | Decentralized mobile edge computing resource discovery and selection method and system |
| CN111556514B (en) * | 2020-04-14 | 2021-09-21 | 北京航空航天大学 | Decentralized mobile edge computing resource discovery and selection method and system |
| CN112579301A (en) * | 2020-12-28 | 2021-03-30 | 北京理工大学 | NDN-based data transmission method for P2P distributed machine learning training system |
| CN112579301B (en) * | 2020-12-28 | 2022-07-01 | 北京理工大学 | NDN-based data transmission method for P2P distributed machine learning training system |
| CN113382053A (en) * | 2021-04-23 | 2021-09-10 | 河南科技大学 | Content active pushing method based on node semi-local centrality and content popularity |
| CN113382053B (en) * | 2021-04-23 | 2022-07-19 | 河南科技大学 | Content active pushing method based on node semi-local centrality and content popularity |
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