[go: up one dir, main page]

CN110995592B - Self-maintenance method and routing forwarding method of a novel pending interest table - Google Patents

Self-maintenance method and routing forwarding method of a novel pending interest table Download PDF

Info

Publication number
CN110995592B
CN110995592B CN201911292150.3A CN201911292150A CN110995592B CN 110995592 B CN110995592 B CN 110995592B CN 201911292150 A CN201911292150 A CN 201911292150A CN 110995592 B CN110995592 B CN 110995592B
Authority
CN
China
Prior art keywords
prefix
pit
interest
data packet
judgment result
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN201911292150.3A
Other languages
Chinese (zh)
Other versions
CN110995592A (en
Inventor
徐雅斌
顾培源
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Information Science and Technology University
Original Assignee
Beijing Information Science and Technology University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beijing Information Science and Technology University filed Critical Beijing Information Science and Technology University
Priority to CN201911292150.3A priority Critical patent/CN110995592B/en
Publication of CN110995592A publication Critical patent/CN110995592A/en
Application granted granted Critical
Publication of CN110995592B publication Critical patent/CN110995592B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/302—Route determination based on requested QoS
    • H04L45/306—Route determination based on the nature of the carried application
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00—Network arrangements or protocols for supporting network services or applications
    • H04L67/50—Network services
    • H04L67/535—Tracking the activity of the user
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00—Network arrangements or protocols for supporting network services or applications
    • H04L67/50—Network services
    • H04L67/60—Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources
    • H04L67/63—Routing a service request depending on the request content or context

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Computer Hardware Design (AREA)
  • General Engineering & Computer Science (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)

Abstract

本发明公开了一种新型待定兴趣表的自维护方法及路由转发方法。本发明针对待定兴趣表快速处理及高效转发的设计需求，通过对PIT的结构进行改进，提出了一种新型待定兴趣表结构，并进一步提出“前缀价值”这一概念，利用热表记录下进入PIT中价值较高的前缀，并且在兴趣包进入以及数据包返回的时候使含有这些前缀的信息能够被优先的查询及处理，进而节省了总体的处理时间，保证了整个NDN路由器的高效运转，具有检索速度快、包往返时延小、丢包率低等优点，可以在较大程度上提高待定兴趣表的转发效率。

Figure 201911292150

The invention discloses a self-maintenance method and a routing forwarding method of a novel pending interest table. Aiming at the design requirements of fast processing and efficient forwarding of pending interest tables, the present invention proposes a new type of pending interest table structure by improving the structure of PIT, and further proposes the concept of "prefix value". Prefixes with higher value in PIT, and information containing these prefixes can be queried and processed preferentially when Interest packets enter and data packets return, thereby saving the overall processing time and ensuring the efficient operation of the entire NDN router. It has the advantages of fast retrieval speed, small packet round-trip delay, and low packet loss rate, which can improve the forwarding efficiency of the pending interest table to a greater extent.

Figure 201911292150

Description

Novel self-maintenance method and route forwarding method of undetermined interest table
Technical Field
The invention relates to the technical field of undetermined interest table matching, in particular to a novel undetermined interest table self-maintenance method and a routing forwarding method.
Background
In order to realize the fast matching of Pending Interest Tables (PIT), researchers have proposed some effective methods, which are mainly classified into two types:
the first type is to improve the PIT performance by optimizing strategies of finding, replacing, deleting and the like of the PIT. Wang et al first proposed the concept of Name Component Encoding (NCE), whereby the idea is to reduce the size of the PIT and to meet the requirements of access frequency. This mechanism can reduce the number of component codes and the code length of each component, but does not degrade the correctness of the longest name prefix match. The name component encoding mechanism separates the encoding process from the longest prefix match so that parallel processing techniques can be used to speed up name lookup. Furthermore, this approach limits the name lookup time to the upper limit of the maximum time between the component encoding process and the longest encoded name prefix match. Based on the above, Dai et al propose the idea of Name Prefix Tree (NPT), and further improve the storage and operation performance of PIT. However, the method needs a certain time to encode and construct the matching tree, so that the method is more suitable for large-scale NDN (Named data networking), and for some smaller-scale NDN networks, an obvious acceleration search effect cannot be achieved due to the increase of extra encoding time.
Huanghui group et al propose an instant triggered PIT entry aging method, which can realize extremely high-precision PIT entry overtime judgment by only paying little storage space. Liu dong and other people change the one-to-one data interaction mode of interest packets and data packets in a named data network, and a method for returning a plurality of data packets by sending one interest packet is realized, so that the route forwarding efficiency is improved. Alubady et al dynamically changes the timeout time for each interest packet entering the PIT, preventing the interest packets that cannot be responded from occupying excess space in the PIT. Although the method realizes policy optimization on the PIT on one aspect, the method does not perform root-source performance improvement on the PIT, has certain limitation, and cannot be completely adapted to all NDN network environments.
The second category is to achieve PIT performance optimization by modifying the PIT structure. Li et al use a Bloom Filter (BF) to spatially compress the PIT, thereby improving the lookup performance of the PIT. Li et al and You et al propose the concepts of MaPIT and DiPIT, respectively, on the basis of a Bloom Filter (BF). The former effectively reduces the on-chip storage consumption through MBF (Mapping BLOOMFILTER, positioning type bloom filter), and the latter promotes the forwarding efficiency by establishing different PITs for different interfaces. However, although the processing speed of the PIT is improved to a certain extent by the algorithm related to MaPIT, more additional storage space is required, and the DiPIT structure has to search each Bloom Filter (BF) to obtain an interface when performing information retrieval, which increases additional retrieval time, and the method increases inevitable retrieval errors due to the defects of the bloom filters.
Varvello et al associate PIT with hash retrieval, thereby increasing lookup speed and reducing storage consumption; on the basis, the xu ya Ping et al propose a named data network PIT storage structure based on an improved MBF, the structure adopts a hash function to realize multiple times of hash mapping so as to improve the retrieval speed, and utilizes Bitmap (Bitmap) to realize dynamic allocation of address offset of an element memory unit, but a hash table is used as static storage, which may cause waste of storage space, and hash collision may also influence the search performance.
Disclosure of Invention
The invention aims to provide a novel undetermined interest table self-maintenance method and a route forwarding method, and aims to solve the problems that the existing undetermined interest table matching search method is long in search time and large in search error, causes storage space waste and cannot adapt to all NDN network environments.
In order to achieve the purpose, the invention provides the following scheme:
a novel self-maintenance method of an undetermined interest table is based on a novel undetermined interest table PIT, and the structure of the novel undetermined interest table comprises a hotlist, a main PIT and an auxiliary PIT; the hot table is positioned at the forefront of the whole novel PIT and is used for recording the prefix and the quantity of the incoming information and not recording the specific information; the main PIT is responsible for storing prefixes in a hot list and requesting high-frequency interest; the auxiliary PIT is used for storing the interest that the prefix and any one of the hot tables cannot be matched and the request frequency is low; the self-maintenance method comprises the following steps:
acquiring last access time and requested total times of each prefix recorded in the hotlist;
determining the time interval and the average access time interval of each prefix from the last access according to the latest access time and the requested total times;
determining the prefix value of each prefix according to the time interval of each prefix from the last access and the average access time interval;
determining a prefix deletion threshold according to the prefix value of each prefix; the prefix deletion threshold comprises a primary prefix deletion threshold and a secondary prefix deletion threshold;
storing the prefix with the prefix value larger than or equal to the primary prefix deletion threshold value and the data packet corresponding to the prefix to the main PIT;
and storing the prefix with the prefix value smaller than the primary prefix deletion threshold value and the data packet corresponding to the prefix to the auxiliary PIT.
Optionally, the determining, according to the latest access time and the requested total number of times, a time interval between each prefix and the last access and an average access time interval specifically includes:
for the ith prefix recorded in the hot table, according to the latest access time T of the ith prefixlast(i) By the formula Tinterval(i)＝Tcurrent(i)-Tlast(i) Determining the time interval T of the ith prefix from the last accessinterval(i) (ii) a Wherein T iscurrent(i) The current time of the ith prefix;
according to the total number R of times of requesting the ith prefixall(i) By the formula Taverage(i)＝(Tlast(i)-Tfirst(i))/RallDetermining an average access time interval T for an ith prefixaverage(i) (ii) a Wherein T isfirst(i) The time when the ith prefix is accessed for the first time.
Optionally, the determining the prefix value of each prefix according to the time interval between each prefix and the last access and the average access time interval specifically includes:
according to the time interval T of last access of the ith prefix distanceinterval(i) By the formula
Figure BDA0002319413760000031
Determining the time interval T of the ith prefix from the last accessinterval(i) Normalized value of (T)i_new(i) (ii) a Wherein T isi_maxDenotes all Tinterval(i) Maximum value of (1); t isi_minDenotes all Tinterval(i) Minimum value of (1);
average access time interval T of ith prefixaverage(i) By the formula
Figure BDA0002319413760000032
Determining an average access time interval T for an ith prefixaverage(i) Normalized value of (T)a_new(i) (ii) a Wherein T isa_maxDenotes all Taverage(i) Maximum value of (1); t isa_minDenotes all Taverage(i) Minimum value of (1);
according to the normalized value Ti_new(i) And Ta_new(i) By the formula
Figure BDA0002319413760000041
Determining prefix value P of ith prefixvalue(i)。
Optionally, the determining a prefix deletion threshold according to the prefix value of each prefix specifically includes:
using a formula
Figure BDA0002319413760000042
Determining a standard deviation sigma of prefix values of all prefixes recorded in the hot table; wherein gi-xi- μ; xi ═ Pvalue(i)；μ＝(x1+x2+...+xn) N; n is the total number of all prefixes recorded in the hot table;
and determining mu-2 sigma as a primary prefix deletion threshold and mu-delta as a secondary prefix deletion threshold according to the standard deviation sigma of prefix values of all prefixes.
Optionally, the self-maintenance method further includes:
judging whether the current number of items of the prefix stored in the main PIT is larger than or equal to a preset item threshold value or not, and obtaining a first judgment result;
if the first judgment result is that the current number of the prefixes stored in the main PIT is larger than or equal to a preset entry threshold, deleting the prefixes of which the prefix values are smaller than a primary prefix deletion threshold in the hot table, and setting the hot table to only store the secondary prefixes of the interest packets from the current moment;
and if the first judgment result is that the current number of entries of prefixes stored in the main PIT is smaller than a preset entry threshold, setting the hot table as a primary prefix of the interest packet stored from the current moment.
Optionally, the self-maintenance method further includes:
and if the current number of the items of the prefixes stored in the main PIT is greater than or equal to a preset item threshold value in two continuous judgments, deleting the prefixes of which the prefix values are less than a secondary prefix deletion threshold value in the hot table.
A route forwarding method based on a novel undetermined interest table is disclosed, wherein the structure of the novel undetermined interest table comprises a hotlist, a main PIT and an auxiliary PIT; the hot table is positioned at the forefront of the whole novel PIT and is used for recording the prefix and the quantity of the incoming information and not recording the specific information; the main PIT is responsible for storing prefixes in a hot list and requesting high-frequency interest; the auxiliary PIT is used for storing the interest that the prefix and any one of the hot tables cannot be matched and the request frequency is low; the route forwarding method comprises the following steps:
acquiring a currently arriving interest packet;
judging whether a data packet corresponding to the interest packet exists in a content storage library CS or not, and obtaining a second judgment result;
if the second judgment result is that the data packet corresponding to the interest packet exists in the CS, directly returning to the data packet;
if the second judgment result is that the data packet corresponding to the interest packet does not exist in the CS, judging whether a prefix corresponding to the interest packet exists in the hot list or not, and obtaining a third judgment result; the prefix comprises a primary prefix and a secondary prefix;
if the third judgment result is that the prefix corresponding to the interest packet exists in the hot table, adding 1 to the requested total times corresponding to the prefix, and updating the latest access time corresponding to the prefix to be the current time; sending the interest packet to the main PIT for matching;
if the third judgment result is that the prefix corresponding to the interest packet does not exist in the hot table, judging whether an available space exists in the hot table or not, and obtaining a fourth judgment result;
if the fourth judgment result is that the available space exists in the hot list, recording the prefix of the interest packet in the hot list, setting the total requested times corresponding to the prefix to be 1, and setting the latest access time corresponding to the prefix to be the current time; sending the interest package to the auxiliary PIT for matching;
if the fourth judgment result is that no available space exists in the hot list, the interest packet is sent to the auxiliary PIT for matching;
if no data packet matched with the prefix of the interest packet is found in the main PIT and the auxiliary PIT, judging whether a data packet matched with the prefix of the interest packet exists in a Forwarding Information Base (FIB) or not, and obtaining a fifth judgment result;
if the fifth judgment result is that a data packet matched with the prefix of the interest packet exists in the FIB, forwarding the interest packet according to an interface list of the FIB;
and if the fifth judgment result is that no data packet matched with the prefix of the interest packet exists in the FIB, discarding the interest packet or rejecting the response.
Optionally, the route forwarding method further includes:
judging whether the returned prefix of the data packet is recorded in the hot table or not, and obtaining a sixth judgment result;
if the sixth judgment result is that the returned prefix of the data packet is recorded in the hot table, sending the data packet to the main PIT for matching;
judging whether a prefix matched with the prefix of the data packet exists in the main PIT or not, and obtaining a seventh judgment result;
if the seventh judgment result is that the prefix matched with the prefix of the data packet exists in the main PIT, forwarding the data packet;
if the seventh judgment result is that the prefix matched with the prefix of the data packet does not exist in the main PIT, discarding the data packet;
if the sixth judgment result is that the returned prefix of the data packet is not recorded in the hot table, sending the data packet to the auxiliary PIT for matching;
judging whether the prefix of the data packet is recorded in the auxiliary PIT or not, and obtaining an eighth judgment result;
if the eighth judgment result is that the prefix of the data packet is not recorded in the auxiliary PIT, the step of sending the data packet to the main PIT for matching is executed;
and if the eighth judgment result is that the prefix of the data packet is recorded in the auxiliary PIT, forwarding the data packet.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a novel self-maintenance method of an undetermined interest table and a route forwarding method, aiming at the design requirements of quick processing and efficient forwarding of the undetermined interest table, the invention provides the concept of prefix value by improving the structure of PIT, records prefixes with higher value entering the PIT by utilizing a hot table, and enables information containing the prefixes to be inquired and processed preferentially when an interest packet enters and a data packet returns, thereby saving the overall processing time, ensuring the efficient operation of the whole NDN router, having the advantages of quick retrieval speed, small packet round-trip delay, low packet loss rate and the like, and being capable of improving the forwarding efficiency of the undetermined interest table to a greater extent.
Furthermore, the invention can ensure that a small amount of information with higher value can enter the main PIT for rapid matching through the recording and distribution of the hotlist; and a large amount of information with smaller value is moved into the sub-PIT for normal matching. Therefore, the priority query and processing with higher value and interest can be effectively guaranteed, and the entries in the table can be responded before the timeout time, so that the packet loss rate is reduced, the round-trip delay is reduced, and the forwarding efficiency of the whole PIT is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
FIG. 1 is a schematic structural diagram of a novel pending interest table provided in the present invention;
FIG. 2 is a schematic diagram illustrating a flow control process of a novel PIT before the self-maintenance method of the hotlist provided by the present invention is performed;
FIG. 3 is a schematic diagram illustrating a flow control process of a novel PIT after a self-maintenance method of a hotlist provided by the present invention is performed;
fig. 4 is a schematic diagram of the NDN processing flow based on the new pending interest table according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a novel undetermined interest table self-maintenance method and a route forwarding method, and aims to solve the problems that the existing undetermined interest table matching search method is long in search time and large in search error, causes storage space waste and cannot adapt to all NDN network environments.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
The invention provides a novel self-maintenance method of an undetermined interest table, which is based on a novel undetermined interest table, and the structure of the novel undetermined interest table comprises a hotlist, a main PIT and an auxiliary PIT.
In the NDN architecture, the pending interest table provides two main functions, namely the aggregation of interest packets and the forwarding of data packets. The same interest packets from different interfaces will be merged in the PIT, with only the first arriving interest packet being routed to the potential responder. When a packet arrives at the PIT, the interface at the time of entry will be fetched from the PIT and transferred out from the interface. The PIT is typically large, and for large NDN networks, may reach the scale of millions to tens of millions. The PIT is used as a core structure for NDN data forwarding, and matching is performed once in the table for each incoming interest packet or data packet, so that the matching speed is undoubtedly low, and the efficiency of the entire NDN forwarding is reduced. In order to solve the problem, the invention provides a novel pending interest table structure based on a hotlist, as shown in fig. 1.
Fig. 1 is a schematic structural diagram of a novel pending interest table provided in the present invention. Referring to fig. 1, the new pending interest table provided by the present invention is composed of a hotlist, a primary PIT and a secondary PIT. The hotlist is located at the forefront of the overall PIT and serves as an "indicator" for data offloading. The hot table is completely transparent to the data stream, does not make any modification to the interest packet or data packet, only records data, only records the prefix and the quantity of the incoming information, does not record specific information, and has extremely small requirement on storage space. By concentrating the prefixes with high value into the hot table for rapid matching, the pressure of concentrated storage of all information in the original framework in one table for matching can be effectively relieved. In addition, the data flow is reasonably distributed, and the load balance can be effectively realized.
The hotlist is used for storing prefixes which are frequently requested within a certain time and have higher values, and then centralized and rapid processing is carried out on information containing the prefixes. The addition of a hot table does add some lookup cost relative to the original PIT structure. However, since the hot table is small overall and only stores the content name prefix instead of the content in the table, the lookup cost of the hot table itself is very small for the PIT overall.
The original PIT structure is divided into two parts, namely a main PIT and an auxiliary PIT, wherein the main PIT is used for storing the prefix in the hot list and requesting the interest with higher frequency, and the auxiliary PIT is used for storing the interest with lower request frequency, which can not be matched with any one of the prefix and the hot list. Besides the storage space, the internal structure of the primary PIT and the secondary PIT is consistent with the original PIT structure.
In the whole network, since the popularity of the data content conforms to Zipf (Zipf) distribution, that is, 20% of the content meets 80% of the request amount of the whole network, and the remaining 80% of the content meets 20% of the request amount of the user. Therefore, in the capacity allocation of the primary PIT and the secondary PIT, the invention sets the size of the primary PIT to be 20% of the maximum number of interest packets which the node can pass through, and sets the size of the secondary PIT to be 80% of the maximum number of interest packets which the node can pass through.
As shown in fig. 1, the hotlist record includes three items:
(1) and the prefix is responsible for recording the prefix name of the incoming interest packet. The primary prefix of the interest package is typically stored by default. When the ratio of the number of the entries in the main PIT is larger than a preset entry threshold lambda, the secondary prefixes of the interest packets are stored in the hot table instead, and the total number of the entries in the main PIT table can be dynamically adjusted in this way, so that the overflow phenomenon of the main PIT table is prevented, and the efficient operation of the whole system is ensured. Wherein the proportion of the number of the items refers to the proportion of the number of the currently stored items to the total number of the items which can be stored.
(2) The number of times, the total number of times that an interest packet containing a certain prefix arrives is recorded, and is referred to as the total number of times that the prefix is requested in the invention.
(3) The time, the last arrival time of the interest packet containing a certain prefix is recorded, and is referred to as the latest access time of the prefix in the invention.
Based on the improved novel undetermined interest table, the invention provides a novel undetermined interest table self-maintenance method, which mainly discusses how the hotlist realizes the data shunting function. Each prefix in the hotlist has its own value attribute. For a prefix, the last access time of the prefix and the total number of times it was requested can be combined to give a value, which is the value of each prefix. The higher the value, the higher the popularity of the prefix is while it is being accessed frequently in the near future. The hotlist calculates the value of each prefix in the list at intervals (typically 10 seconds) and deletes prefixes that do not meet a predetermined threshold.
The invention obtains the value of each prefix by using a normalization method.
Let TlastThe time when a certain prefix is accessed last time, the current time TcurrentThe time interval from the last access is:
Tinterval＝Tcurrent-Tlast (1)
let RallIs the total number of times the prefix is requested, TfirstThe time when the prefix is accessed for the first time, the average access time interval of the prefix is:
Taverage＝(Tlast-Tfirst)/Rall (2)
Taveragethe smaller the number of times the data is accessed in a short time.
Let Ti_maxRepresenting T in all dataintervalThe largest data, Ti _ min represents the data with the smallest Tinterval among all the data, for TintervalCarrying out normalization treatment to obtain:
Figure BDA0002319413760000091
let Ta_maxRepresenting Tavera in all datageMaximum value of (1), Ta_minRepresenting T in all dataaverageNormalized to obtain:
Figure BDA0002319413760000092
thus each prefix value is:
Figure BDA0002319413760000101
based on the principle, the novel self-maintenance method of the undetermined interest list provided by the invention comprises the following steps:
step 101: and acquiring the last access time and the total requested times of each prefix recorded in the hot table.
Step 102: determining the time interval and the average access time interval of each prefix from the last access according to the latest access time and the requested total times; the method specifically comprises the following steps:
for the ith prefix recorded in the hot table, according to the latest access time T of the ith prefixlast(i) By the formula Tinterval(i)＝Tcurrent(i)-Tlast(i) Determining the time interval T of the ith prefix from the last accessinterval(i) (ii) a Wherein T iscurrent(i) The current time of the ith prefix;
according to the total number R of times of requesting the ith prefixall(i) By the formula Taverage(i)＝(Tlast(i)-Tfirst(i))/RallDetermining an average access time interval T for an ith prefixaverage(i) (ii) a Wherein T isfirst(i) The time when the ith prefix is accessed for the first time.
Step 103: determining the prefix value of each prefix according to the time interval of each prefix from the last access and the average access time interval; the method specifically comprises the following steps:
according to the time interval T of last access of the ith prefix distanceinterval(i) By the formula
Figure BDA0002319413760000102
Determining the time interval T of the ith prefix from the last accessinterval(i) Normalized value of (T)i_new(i) (ii) a Wherein T isi_maxDenotes all Tinterval(i) Maximum value of (1); t isi_minDenotes all Tinterval(i) Minimum value of (1);
average access time interval T of ith prefixaverage(i) By the formula
Figure BDA0002319413760000103
Determining an average access time interval T for an ith prefixaverage(i) Normalized value of (T)a_new(i) (ii) a Wherein T isa_maxDenotes all Taverage(i) Maximum value of (1); t isa_minDenotes all Taverage(i) Minimum value of (1);
according to the normalized value Ti_new(i) And Ta_new(i) By the formula
Figure BDA0002319413760000104
Determining prefix value P of ith prefixvalue(i)。
Step 104: determining a prefix deletion threshold based on the prefix value for each prefix.
In order to ensure the accuracy and timeliness of hot list data distribution, the value of each prefix needs to be calculated periodically for a hot list, and prefixes which do not meet a preset threshold value are deleted. The invention deletes prefixes with significantly less value than other prefixes according to the Lautacriterion (PC). The Lauda criterion is that a group of detection data is supposed to only contain random errors, the detection data is calculated to obtain a standard deviation, an interval is determined according to a certain probability, and all data exceeding the standard deviation are removed. Each prefix value in the hotlist is defined as x1, x2 … xn. Then, the average is:
μ＝(x1+x2+...+xn)/n (6)
the residual error is:
gi＝xi-μ (7)
according to the Bessel (Bessel formula) formula, the standard deviation of the values of these prefixes can be found as:
Figure BDA0002319413760000111
the Laviand criterion considers the probability of a numerical distribution in (μ - σ, μ + σ) to be 0.6827 and the probability of a numerical distribution in (μ -2 σ, μ +2 σ) to be 0.9544. Therefore, the value of the prefix value is mostly concentrated in the interval (mu-2 sigma, mu +2 sigma), and the possibility of exceeding the range only accounts for less than 4%. Because only prefixes of a lesser value typically need to be deleted, only prefixes of values less than μ -2 σ need to be deleted per maintenance.
Through the self-maintenance strategy of the hot table, the effect of 'cache pollution' brought by historical data to the hot table can be prevented. Content prefixes frequently requested in a recent period of time can be successfully retained in the hot table, and content prefixes with obviously reduced request times in the recent period of time can be removed, so that the freshness of the hot table and the timeliness of entries in the hot table are ensured, and the internal logic of the hot table is realized.
Therefore, the determining a prefix deletion threshold according to the prefix value of each prefix specifically includes:
using a formula
Figure BDA0002319413760000112
Determining a standard deviation sigma of prefix values of all prefixes recorded in the hot table; wherein gi-xi- μ; xi ═ Pvalue(i)；μ＝(x1+x2+...+xn) N; n is the total number of all prefixes recorded in the hot table.
The prefix deletion threshold includes a primary prefix deletion threshold and a secondary prefix deletion threshold. And determining mu-2 sigma as a primary prefix deletion threshold and mu-delta as a secondary prefix deletion threshold according to the standard deviation sigma of prefix values of all prefixes.
Step 105: and storing the prefix with the prefix value larger than or equal to the primary prefix deletion threshold value and the data packet corresponding to the prefix to the main PIT.
Step 106: and storing the prefix with the prefix value smaller than the primary prefix deletion threshold value and the data packet corresponding to the prefix to the auxiliary PIT.
Storing the prefix with the prefix value larger than or equal to the primary prefix deletion threshold value and the corresponding data packet to the main PIT when the self-maintenance strategy of the hot list is firstly carried out; and storing the prefix with the prefix value smaller than the primary prefix deletion threshold value and the data packet corresponding to the prefix to the auxiliary PIT.
The invention also adds a flow control mechanism to the main PIT aiming at the condition of sudden burst of network flow which may occur. When the number of entries in the primary PIT reaches 80% of the size of the primary PIT, a maintenance strategy of the hot table is immediately executed, prefixes with values smaller than mu-2 sigma are deleted, and a certain space is reserved for the hot table. At this time, the incoming interest package only stores the secondary prefix and replaces the original primary prefix in the hot table instead. The hot table follows the longest prefix match principle, so that traffic under the original primary prefix will partially flow into the secondary PIT, thus controlling the traffic entering the primary PIT.
Therefore, the self-maintenance method further comprises:
judging whether the current number of items of the prefix stored in the main PIT is larger than or equal to a preset item threshold value or not, and obtaining a first judgment result;
if the first judgment result is that the current number of the prefixes stored in the main PIT is larger than or equal to a preset entry threshold, deleting the prefixes of which the prefix values are smaller than a primary prefix deletion threshold in the hot table, and setting the hot table to only store the secondary prefixes of the interest packets from the current moment;
and if the first judgment result is that the current number of entries of prefixes stored in the main PIT is smaller than a preset entry threshold, setting the hot table as a primary prefix of the interest packet stored from the current moment.
If the number of entries in the primary PIT table is more than 80% of the table capacity for at least two consecutive maintenances, a secondary hot table maintenance policy is implemented. According to the LayEd criterion, the probability that the prefix value in the hot table is distributed in (mu-sigma, mu + sigma) is 0.6827, and the prefix with the value smaller than mu-sigma in the hot table is deleted, so that more space is provided for the hot table to store the newly arrived secondary prefix.
Therefore, the self-maintenance method further comprises:
and if the current number of the items of the prefixes stored in the main PIT is greater than or equal to a preset item threshold value in two continuous judgments, deleting the prefixes of which the prefix values are less than a secondary prefix deletion threshold value in the hot table.
When the hot table maintenance time is up, if the number of the entries in the main PIT is found to be less than 80%, executing a conventional hot table maintenance strategy, and changing the reserved secondary prefixes in the hot table back to the stored primary prefixes. By adopting the method, the phenomenon that the entries in the hot list are filled with useless prefixes due to the accidental occurrence of large bursty flow can be prevented. The flow control process of PIT is shown in fig. 2 and 3.
Fig. 2 is a schematic view of a flow control process of the novel PIT before the self-maintenance policy of the hot table provided by the present invention is executed, and fig. 3 is a schematic view of a flow control process of the novel PIT after the self-maintenance policy of the hot table provided by the present invention is executed. Referring to fig. 2, the self-maintenance policy of the hot table is before execution, the prefix youtube.com is recorded in the hot table, so all interests under the primary prefix youtube.com go into the master PIT for matching. Referring to fig. 3, when the number of entries in the primary PIT increases to a preset entry threshold, the hot table deletes part of the prefixes within the table through the self-maintenance policy and the hot table instead stores only the secondary prefixes of interest. For the interest packages of the subsequent coming youtube websites, the secondary prefixes youtube.com/1 and youtube.com/2 are stored in the hot table, and the original primary prefixes are deleted. When a new interest packet arrives at the hot table, the longest prefix matching principle is followed in the hot table, and all the interests under youtube.com which do not belong to youtube.com/1 or youtube.com/2 are shunted to the auxiliary PIT.
This approach works better in situations where there are large data requests (e.g., video requests) in a short period of time. Because the traffic in this case is concentrated in several or several tens of prefixes, the hotlist maintenance strategy of the present invention is a normalization process based on the current distance from the last visited time and the current maximum value of the average visited time interval. Therefore, in this case, the differentiation of different prefix values is more obvious compared with random flow, more space is left for storing new secondary prefixes, and therefore the flow control of the pending interest table is more facilitated.
Aiming at the design requirements of rapid processing and efficient forwarding of a Pending Interest Table (PIT) in a Named Data Network (NDN), the invention provides a novel Pending Interest Table structure by improving the structure of the PIT, further provides the concept of prefix value, records prefixes with higher value entering the PIT by using a hot Table, and enables information containing the prefixes to be inquired and processed preferentially when an Interest packet enters and a Data packet returns, thereby saving the overall processing time and ensuring the efficient operation of the whole NDN router.
The invention constructs the undetermined interest list structure based on the hotlist, takes the hotlist as an indicator of data distribution, records the prefix and the quantity of the incoming information, and distributes according to the prefix value. The original PIT structure is divided into two parts, namely a main PIT and an auxiliary PIT, wherein the main PIT is used for storing the prefix in the hot list and requesting the interest with higher frequency, and the auxiliary PIT is used for storing the interest with lower request frequency, which can not be matched with any one of the prefix and the hot list. Besides the storage space, the internal structures of the main PIT and the auxiliary PIT are consistent with the original PIT structure, and the hot table can play a role in data distribution in route forwarding through the structural improvement of the original undetermined interest table.
After the implementation of the self-maintenance method of the hot table, the present invention further discusses how to implement the whole route forwarding by using the hot table. The flow of NDN processing based on the new pending interest table is shown in fig. 4. In fig. 4, "interest" indicates an interest packet, and "Date" indicates a data packet.
Referring to fig. 4, assuming that a request youtube, com/music/jay/a.mp3 arrives, for the just-coming interest packet, first accessing a Content Store (CS) which is responsible for storing the data that has been requested by the router, and if the Content Store queries the data packet corresponding to the interest packet, returning the data packet directly without performing subsequent operations; otherwise, if no matched data exists, the interest packet is sent to the novel PIT for matching.
After entering the new type of PIT, first check if there is a primary or secondary prefix (youtube. If so, the total number of times R that prefix is requestedallAdding 1, updating the latest access time T corresponding to the prefix in the hot listlastIs the current time. Then, the request is moved into a main PIT for matching; if there is no match, look up the hotlistWhether it is full. If the hot table has space, the prefix of the interest packet is placed in the hot table, and the number of times R is recordedallSet to 1, time TlastAnd setting the current time, and moving the interest packet into the main PIT for matching. If the hot table is full, the prefixes which are requested more frequently and are accessed frequently in the near future are stored in the table at the moment, and the interest packet is moved into the auxiliary PIT at the moment.
In the process of searching the interest packet, if the CS and the PIT have no result, the FIB is searched, if the corresponding content name entry is found in the FIB, the node receives the interest packet for the first time, the interest packet is forwarded according to an interface list (an interface which does not contain the interest packet) of the FIB, and a new entry is added in the PIT. If there is no result in any of the three structures, it indicates that there is no relevant matching route, the node cannot process this interest packet and discards it. A Forwarding Information Base (FIB) records a next hop interface of a current node reaching a content providing node, which is equivalent to an FIB in an IP network, and is automatically generated by a routing protocol, and is a basis for forwarding an interest packet. Unlike IP forwarding, NDN forwarding allows a set of forwarding outlets, not limited to one.
When the data packet corresponding to the request returns, the hot table is searched first, and if the prefix is in the hot table, the data packet enters the main PIT to search for corresponding information; otherwise, entering a secondary PIT table for matching.
In addition, the invention also considers the situation that after a certain prefix in the hot table is deleted in the data forwarding process, the data packet is returned and goes to the auxiliary PIT for query because the prefix can not be found in the hot table. In this respect, the present invention performs the following processing: when the data packet returns, if the prefix exists in the hot table, the data packet is directly inquired to the main PIT, if the prefix does not exist in the hot table, the data packet is firstly inquired to the auxiliary PIT, and if the prefix does not exist in the auxiliary PIT, the data packet is inquired to the main PIT again. Because the primary PIT is relatively small, the lookup time can be increased slightly while avoiding possible problems, thereby improving the overall forwarding efficiency of the PIT.
By adopting the route forwarding mode, a small amount of information with higher value can enter the main PIT for rapid matching; and a large amount of information with smaller value is moved into the sub-PIT for normal matching. Therefore, the priority query and processing with higher value interest can be effectively guaranteed, and the forwarding efficiency of the whole PIT is improved.
Based on the above principle, the invention provides a routing forwarding method based on a novel undetermined interest table, as shown in fig. 4, the novel undetermined interest table comprises a hotlist, a main PIT and an auxiliary PIT; the route forwarding method comprises the following steps:
acquiring a currently arriving interest packet;
judging whether a data packet corresponding to the interest packet exists in a content storage library CS or not, and obtaining a second judgment result;
if the second judgment result is that the data packet corresponding to the interest packet exists in the CS, directly returning to the data packet;
if the second judgment result is that the data packet corresponding to the interest packet does not exist in the CS, judging whether a prefix corresponding to the interest packet exists in the hot list or not, and obtaining a third judgment result; the prefix comprises a primary prefix and a secondary prefix;
if the third judgment result is that the prefix corresponding to the interest packet exists in the hot table, adding 1 to the requested total times corresponding to the prefix, and updating the latest access time corresponding to the prefix to be the current time; sending the interest packet to the main PIT for matching;
if the third judgment result is that the prefix corresponding to the interest packet does not exist in the hot table, judging whether an available space exists in the hot table or not, and obtaining a fourth judgment result;
if the fourth judgment result is that the available space exists in the hot list, recording the prefix of the interest packet in the hot list, setting the total requested times corresponding to the prefix to be 1, and setting the latest access time corresponding to the prefix to be the current time; sending the interest package to the auxiliary PIT for matching;
if the fourth judgment result is that no available space exists in the hot list, the interest packet is sent to the auxiliary PIT for matching;
if no data packet matched with the prefix of the interest packet is found in the main PIT and the auxiliary PIT, judging whether a data packet matched with the prefix of the interest packet exists in a Forwarding Information Base (FIB) or not, and obtaining a fifth judgment result;
if the fifth judgment result is that a data packet matched with the prefix of the interest packet exists in the FIB, forwarding the interest packet according to an interface list of the FIB;
and if the fifth judgment result is that no data packet matched with the prefix of the interest packet exists in the FIB, discarding the interest packet or rejecting the response.
When the data packet corresponding to the interest packet is returned, the route forwarding method further includes:
judging whether the returned prefix of the data packet is recorded in the hot table or not, and obtaining a sixth judgment result;
if the sixth judgment result is that the returned prefix of the data packet is recorded in the hot table, sending the data packet to the main PIT for matching;
judging whether a prefix matched with the prefix of the data packet exists in the main PIT or not, and obtaining a seventh judgment result;
if the seventh judgment result is that the prefix matched with the prefix of the data packet exists in the main PIT, forwarding the data packet;
if the seventh judgment result is that the prefix matched with the prefix of the data packet does not exist in the main PIT, discarding the data packet;
if the sixth judgment result is that the returned prefix of the data packet is not recorded in the hot table, sending the data packet to the auxiliary PIT for matching;
judging whether the prefix of the data packet is recorded in the auxiliary PIT or not, and obtaining an eighth judgment result;
if the eighth judgment result is that the prefix of the data packet is not recorded in the auxiliary PIT, the step of sending the data packet to the main PIT for matching is executed;
and if the eighth judgment result is that the prefix of the data packet is recorded in the auxiliary PIT, forwarding the data packet.
The invention designs a novel undetermined interest table structure based on a hotlist, records and screens the prefix of an interest packet about to enter the undetermined interest table, and establishes an independent 'priority channel' for the information which often passes through the undetermined interest table. The concept of prefix value is put forward in the pending interest table, and information is processed in a grading way according to the value of the prefix, so that the interest packet containing the prefix with higher value can be inquired and processed preferentially. Furthermore, the invention also provides a self-maintenance method of the hot list, which realizes the dynamic adjustment of the data inflow direction, ensures the interest of higher value in the recent period of time processed in the priority channel, and can effectively prevent the overflow phenomenon of the list to be determined.
Aiming at the design requirements of quick processing and efficient forwarding of the interest table to be determined, the invention provides a novel structure of the interest table to be determined by improving the structure of the PIT, and further provides a concept of prefix value, records prefixes with higher values entering the PIT by using a hot table, and enables information containing the prefixes to be inquired and processed preferentially when the interest packet enters and the data packet returns, thereby saving the overall processing time and ensuring the efficient operation of the whole NDN router.
Through recording and shunting of the hotlist, a small amount of information with higher value can enter the main PIT for rapid matching; and a large amount of information with smaller value is moved into the sub-PIT for normal matching. Therefore, the priority query and processing with higher value and interest can be effectively guaranteed, and the entries in the table can be responded before the timeout time, so that the packet loss rate is reduced, the round-trip delay is reduced, and the forwarding efficiency of the whole PIT is improved.
Therefore, compared with the existing method for improving the performance of the to-be-determined interest table of the named data network, the method provided by the invention has the advantages of high retrieval speed, small packet round-trip delay, low packet loss rate and the like, and can improve the forwarding efficiency of the to-be-determined interest table to a greater extent. The invention adopts a novel undetermined interest table structure based on the hotlist, realizes the rapid search of the items on the PIT, improves the search rate and avoids the search error and the waste of the storage space. The method can be suitable for NDN networks of various scales, and the problem that the existing method cannot adapt to all NDN network environments is solved.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (8)

1. A novel self-maintenance method of an undetermined interest table is characterized in that the novel self-maintenance method of the undetermined interest table is based on a novel undetermined interest table PIT, and the structure of the novel undetermined interest table comprises a hotlist, a main PIT and an auxiliary PIT; the hot table is positioned at the forefront of the whole novel PIT and is used for recording the prefix and the quantity of the incoming information and not recording the specific information; the main PIT is responsible for storing prefixes in a hot list and requesting high-frequency interest; the auxiliary PIT is used for storing the interest that the prefix and any one of the hot tables cannot be matched and the request frequency is low; the hotlist is used for storing prefixes which are frequently requested within a certain time and have higher value, and further performing centralized rapid processing on information containing the prefixes;
the self-maintenance method comprises the following steps:
acquiring last access time and requested total times of each prefix recorded in the hotlist;
determining the time interval between each prefix and the last visit and the average visit time interval according to the latest visit time and the requested total times;
determining the prefix value of each prefix according to the time interval of each prefix from the last access and the average access time interval;
determining a prefix deletion threshold according to the prefix value of each prefix; the prefix deletion threshold comprises a primary prefix deletion threshold and a secondary prefix deletion threshold;
storing the prefix with the prefix value larger than or equal to the primary prefix deletion threshold value and the data packet corresponding to the prefix to the main PIT;
and storing the prefix with the prefix value smaller than the primary prefix deletion threshold value and the data packet corresponding to the prefix to the auxiliary PIT.
2. The method of claim 1, wherein the determining the time interval between each prefix and the last access and the average access time interval according to the latest access time and the total number of requested times comprises:
for the ith prefix recorded in the hot table, according to the latest access time T of the ith prefixlast(i) By the formula Tinterval(i)＝Tcurrent(i)-Tlast(i) Determining the time interval T of the ith prefix from the last accessinterval(i) (ii) a Wherein T iscurrent(i) The current time of the ith prefix;
according to the total number R of times of requesting the ith prefixall(i) By the formula Taverage(i)＝(Tlast(i)-Tfirst(i))/RallDetermining an average access time interval T for an ith prefixaverage(i) (ii) a Wherein T isfirst(i) The time when the ith prefix is accessed for the first time.
3. The method of claim 2, wherein determining a prefix value for each prefix based on a time interval between each prefix and a last access and an average access time interval comprises:
according to the time interval T of last access of the ith prefix distanceinterval(i) By the formula
Figure FDA0003151208340000021
Determining the time interval T of the ith prefix from the last accessinterval(i) Normalized value of (T)i_new(i) (ii) a Wherein T isi_maxDenotes all Tinterval(i) Maximum value of (1); t isi_minDenotes all Tinterval(i) Minimum value of (1);
average access time interval T of ith prefixaverage(i) By the formula
Figure FDA0003151208340000022
Determining an average access time interval T for an ith prefixaverage(i) Normalized value of (T)a_new(i) (ii) a Wherein T isa_maxDenotes all Taverage(i) Maximum value of (1); t isa_minDenotes all Taverage(i) Minimum value of (1);
according to the normalized value Ti_new(i) And Ta_new(i) By the formula
Figure FDA0003151208340000023
Determining prefix value P of ith prefixvalue(i)。
4. The method of claim 3, wherein the determining a prefix deletion threshold according to the prefix value of each prefix specifically comprises:
using a formula
Figure FDA0003151208340000024
Determining a standard deviation sigma of prefix values of all prefixes recorded in the hot table; wherein gi-xi- μ; x is the number ofi＝Pvalue(i)；μ＝(x1+x2+...+xn) N; n is the total number of all prefixes recorded in the hot table;
and determining mu-2 sigma as a primary prefix deletion threshold and mu-delta as a secondary prefix deletion threshold according to the standard deviation sigma of prefix values of all prefixes.
5. The novel self-maintenance method of pending interest tables of claim 4, further comprising:
judging whether the current number of items of the prefix stored in the main PIT is larger than or equal to a preset item threshold value or not, and obtaining a first judgment result;
if the first judgment result is that the current number of the prefixes stored in the main PIT is larger than or equal to a preset entry threshold, deleting the prefixes of which the prefix values are smaller than a primary prefix deletion threshold in the hot table, and setting the hot table to only store the secondary prefixes of the interest packets from the current moment;
and if the first judgment result is that the current number of entries of prefixes stored in the main PIT is smaller than a preset entry threshold, setting the hot table as a primary prefix of the interest packet stored from the current moment.
6. The novel self-maintenance method of pending interest tables of claim 5, further comprising:
and if the current number of the items of the prefixes stored in the main PIT is greater than or equal to a preset item threshold value in two continuous judgments, deleting the prefixes of which the prefix values are less than a secondary prefix deletion threshold value in the hot table.
7. A route forwarding method based on a novel undetermined interest table is characterized in that the structure of the novel undetermined interest table comprises a hotlist, a main PIT and an auxiliary PIT; the hot table is positioned at the forefront of the whole novel PIT and is used for recording the prefix and the quantity of the incoming information and not recording the specific information; the main PIT is responsible for storing prefixes in a hot list and requesting high-frequency interest; the auxiliary PIT is used for storing the interest that the prefix and any one of the hot tables cannot be matched and the request frequency is low; the hotlist is used for storing prefixes which are frequently requested within a certain time and have higher value, and further performing centralized rapid processing on information containing the prefixes; the route forwarding method comprises the following steps:
acquiring a currently arriving interest packet;
judging whether a data packet corresponding to the interest packet exists in a content storage library CS or not, and obtaining a second judgment result;
if the second judgment result is that the data packet corresponding to the interest packet exists in the CS, directly returning to the data packet;
if the second judgment result is that the data packet corresponding to the interest packet does not exist in the CS, judging whether a prefix corresponding to the interest packet exists in the hot list or not, and obtaining a third judgment result; the prefix comprises a primary prefix and a secondary prefix;
if the third judgment result is that the prefix corresponding to the interest packet exists in the hot table, adding 1 to the requested total times corresponding to the prefix, and updating the latest access time corresponding to the prefix to be the current time; sending the interest packet to the main PIT for matching;
if the third judgment result is that the prefix corresponding to the interest packet does not exist in the hot table, judging whether an available space exists in the hot table or not, and obtaining a fourth judgment result;
if the fourth judgment result is that the available space exists in the hot list, recording the prefix of the interest packet in the hot list, setting the total requested times corresponding to the prefix to be 1, and setting the latest access time corresponding to the prefix to be the current time; sending the interest package to the auxiliary PIT for matching;
if the fourth judgment result is that no available space exists in the hot list, the interest packet is sent to the auxiliary PIT for matching;
if no data packet matched with the prefix of the interest packet is found in the main PIT and the auxiliary PIT, judging whether a data packet matched with the prefix of the interest packet exists in a Forwarding Information Base (FIB) or not, and obtaining a fifth judgment result;
if the fifth judgment result is that a data packet matched with the prefix of the interest packet exists in the FIB, forwarding the interest packet according to an interface list of the FIB;
and if the fifth judgment result is that no data packet matched with the prefix of the interest packet exists in the FIB, discarding the interest packet or rejecting the response.
8. The routing forwarding method based on the new type of pending interest table as claimed in claim 7, wherein the routing forwarding method further comprises:
judging whether the returned prefix of the data packet is recorded in the hot table or not, and obtaining a sixth judgment result;
if the sixth judgment result is that the returned prefix of the data packet is recorded in the hot table, sending the data packet to the main PIT for matching;
judging whether a prefix matched with the prefix of the data packet exists in the main PIT or not, and obtaining a seventh judgment result;
if the seventh judgment result is that the prefix matched with the prefix of the data packet exists in the main PIT, forwarding the data packet;
if the seventh judgment result is that the prefix matched with the prefix of the data packet does not exist in the main PIT, discarding the data packet;
if the sixth judgment result is that the returned prefix of the data packet is not recorded in the hot table, sending the data packet to the auxiliary PIT for matching;
judging whether the prefix of the data packet is recorded in the auxiliary PIT or not, and obtaining an eighth judgment result;
if the eighth judgment result is that the prefix of the data packet is not recorded in the auxiliary PIT, the step of sending the data packet to the main PIT for matching is executed; and if the eighth judgment result is that the prefix of the data packet is recorded in the auxiliary PIT, forwarding the data packet.
CN201911292150.3A 2019-12-16 2019-12-16 Self-maintenance method and routing forwarding method of a novel pending interest table Expired - Fee Related CN110995592B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911292150.3A CN110995592B (en) 2019-12-16 2019-12-16 Self-maintenance method and routing forwarding method of a novel pending interest table

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911292150.3A CN110995592B (en) 2019-12-16 2019-12-16 Self-maintenance method and routing forwarding method of a novel pending interest table

Publications (2)

Publication Number Publication Date
CN110995592A CN110995592A (en) 2020-04-10
CN110995592B true CN110995592B (en) 2021-09-07

Family

ID=70093943

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911292150.3A Expired - Fee Related CN110995592B (en) 2019-12-16 2019-12-16 Self-maintenance method and routing forwarding method of a novel pending interest table

Country Status (1)

Country Link
CN (1) CN110995592B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115002036B (en) * 2022-05-26 2023-07-25 国网河北省电力有限公司电力科学研究院 NDN network congestion control method, electronic equipment and storage medium

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103491003A (en) * 2012-06-14 2014-01-01 华为技术有限公司 Content router and message processing method of content router
CN103595637A (en) * 2013-10-27 2014-02-19 西安电子科技大学 Method for utilizing content-centric network nodes to process data based on tree and hash table
CN103237068B (en) * 2013-04-17 2015-11-25 北京科技大学 The differentiable stream media buffer replacing method of contents attribute in CDN-P2P
CN105376160A (en) * 2014-08-11 2016-03-02 帕洛阿尔托研究中心公司 Reputation-based instruction processing over an information centric network
CN106899692A (en) * 2017-03-17 2017-06-27 重庆邮电大学 A kind of content center network node data buffer replacing method and device
CN109428822A (en) * 2017-09-01 2019-03-05 华为技术有限公司 A kind of Name Lookup method and the network equipment
CN109446844A (en) * 2018-11-15 2019-03-08 北京信息科技大学 A kind of method for secret protection and system towards big data publication

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10122624B2 (en) * 2016-07-25 2018-11-06 Cisco Technology, Inc. System and method for ephemeral entries in a forwarding information base in a content centric network
CN106357641B (en) * 2016-09-18 2019-10-22 中国科学院信息工程研究所 Defense method and device for interest packet flooding attack in content-centric network
CN108347442B (en) * 2018-02-09 2019-10-11 重庆邮电大学 Method and system for detecting interest packet flooding attack in content-centric network
CN110166464B (en) * 2019-05-27 2021-10-15 北京信息科技大学 A method and system for detecting interest flooding attacks in content-centric networks
CN110233901A (en) * 2019-06-20 2019-09-13 南通大学 A kind of content center network caching method and system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103491003A (en) * 2012-06-14 2014-01-01 华为技术有限公司 Content router and message processing method of content router
CN103237068B (en) * 2013-04-17 2015-11-25 北京科技大学 The differentiable stream media buffer replacing method of contents attribute in CDN-P2P
CN103595637A (en) * 2013-10-27 2014-02-19 西安电子科技大学 Method for utilizing content-centric network nodes to process data based on tree and hash table
CN105376160A (en) * 2014-08-11 2016-03-02 帕洛阿尔托研究中心公司 Reputation-based instruction processing over an information centric network
CN106899692A (en) * 2017-03-17 2017-06-27 重庆邮电大学 A kind of content center network node data buffer replacing method and device
CN109428822A (en) * 2017-09-01 2019-03-05 华为技术有限公司 A kind of Name Lookup method and the network equipment
CN109446844A (en) * 2018-11-15 2019-03-08 北京信息科技大学 A kind of method for secret protection and system towards big data publication

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Resist Interest Flooding Attacks via Entropy–SVM and Jensen–Shannon Divergence in Information-Centric Networking;Ting Zhi;《IEEE SYSTEMS JOURNAL》;20190916(第14卷第2期);全文 *
一种即时触发的PIT表项老化方法;黄慧群;《信息工程大学学报》;20151231(第16卷第2期);全文 *

Also Published As

Publication number Publication date
CN110995592A (en) 2020-04-10

Similar Documents

Publication Publication Date Title
CN108337172B (en) Large-scale OpenFlow flow table accelerated searching method
CN109921996A (en) A kind of virtual flow stream searching method of high performance OpenFlow
JP6190754B2 (en) Apparatus and method for table lookup using centralized memory pool in network switch
US8204060B2 (en) Method and system for facilitating forwarding a packet in a content-centric network
EP2793436B1 (en) Content router forwarding plane architecture
CN104584512B (en) An Approach to Collaborative Caching in Content-Oriented Networking
CN102971732A (en) System architecture for integrated hierarchical query processing for key/value stores
US9848056B2 (en) Data processing method, router, and NDN system
CN103841018B (en) Content centric network multiport forwarding method and router
JP2006313949A (en) Packet transfer device
US8539041B2 (en) Method, apparatus, and network system for acquiring content
CN111131029B (en) High-energy-efficiency OpenFlow flow table searching method supporting rule dependence
CN108900570A (en) A kind of buffer replacing method based on content value
CN111200627A (en) A method and device for determining a forwarding port in an information center network
CN106899692A (en) A kind of content center network node data buffer replacing method and device
CN110995592B (en) Self-maintenance method and routing forwarding method of a novel pending interest table
CN104737505B (en) Method for routing and routing node based on caching
US20170012874A1 (en) Software router and methods for looking up routing table and for updating routing entry of the software router
CN109951390A (en) A network device based on PopBetw strategy and its cooperative route caching method
Wu et al. Data lifetime enhancement for improving QoS in NDN
US20170264531A1 (en) Probabilistic http request routing
US10684960B2 (en) Managing cache memory in a network element based on costs associated with fetching missing cache entries
CN106230723B (en) A kind of message forwarding cache method and device
CN100487697C (en) Searching method by using modified hash method
CN109729514B (en) Method for quickly inquiring dynamic position information of mobile network entity

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20210907