CN103747083B - A kind of content delivery method based on CCN - Google Patents

Abstract

The present invention relates to a kind of content delivery method based on CCN, content propelling movement person is initiating communication initiatively, just content directly can be pushed to without the need to user's request and receive user, without the need to repeatedly mutual, by the triggering of a special interests bag, the reverse propelling movement path of multiple content can be set up, greatly reduce communication delay and link load.The present invention can be applied in numerous application scenarios, and the microblogging, large files transmission, stock, weather forecast etc. that such as often use now, enriched the practical application of CCN network.

Description

A kind of content delivery method based on CCN

Technical field

The invention belongs to technical field of the computer network, be specifically related to a kind of content delivery method based on CCN.

Background technology

Along with the development of interconnected web-based applications changes, the existing the Internet based on TCP/IP also exposes many being not suitable with gradually, and current, the problem that the Internet mainly exposes has: dangerous, poor mobility, poor reliability, very flexible.The extensibility of the Internet and effective contents distribution problem have caused the research boom of nerve of a covering (Overlay Network) and content distributing network (Content Delivery Network) scholars.The Internet is just progressively changed to content center by host center.CCN(content centric network, content center network) be the research direction of comparatively main flow at present.

Summary of the invention

For overcoming above-mentioned the deficiencies in the prior art, the present invention proposes a kind of content delivery method based on CCN, thus effectively promote the performance of CCN network, it is characterized in that:

Propelling movement side's structure special interests bag also sends this special interests bag;

Intermediate node resolves interest bag, and judges whether comprise PIT specific fields in interest bag;

If intermediate node detects PIT specific fields, then revise PIT entry;

Intermediate node amendment port, sets up reverse PIT;

Intermediate node according to FIB route by described special interests Packet forwarding to next node;

Recipient sets up reverse PIT;

Propelling movement side triggers interest bag inquiry PIT and mates entry;

The port repeating that content records by propelling movement side from PIT.

Preferably, the result judging whether to comprise in interest bag PIT specific fields if described is no, then continue process according to normal CCN flow process.

Preferably, described normal CCN flow process is specially:

When requesting party needs request content, initiatively send interest bag; Intermediate node understands query contents buffer memory (CS), PIT and FIB successively after receiving interest bag;

If do not have the content that requesting party asks in CS, intermediate node records the port numbers receiving interest bag on PIT;

Intermediate node forwards this interest bag according to FIB; Each interest is surrounded by a random number (nonce); Each CCN node, when receiving interest bag, judges the title of interest bag, and when receiving one with title but the interest bag of different nonce, CCN adds the port that this interest bag is come in PIT; If the interest bag title received is all identical with both nonce, then CCN node will abandon this repetition interest bag;

Content source searches the CS of oneself after receiving interest bag, if there is the content that requesting party asks in CS, then press original route according to the port information of PIT record; This content is turned round via intermediate node;

Copy of content is buffered in local CS by the intermediate node of content process.

Preferably, content recipient title in the special interests bag constructed, to need in the burst quantity that pushes and initial burst number and content name one or more.

Preferably, if described intermediate node detects PIT specific fields, then revise PIT entry and comprise further: the assembly removing PIT flag bit and last expression PIT quantity above;

Build the continuous print interest bag that several are new;

Search the forwarding port of interest bag, interest Packet forwarding port is added in PIT entry;

After having added PIT entry, do not forward this several interest bags, directly interest bag is abandoned.

Preferably, the port repeating that content records by described propelling movement side from PIT comprises further:

Search after CS finds matching content, directly carried out the forwarding of content according to the PIT set up.

Preferably, described special interests Packet forwarding comprises to next node according to FIB route by described intermediate node further:

Intermediate node forwards special interests bag, until the reception arriving content stops forwarding just now.

Preferably, intermediate node does not forward for several interest bags built when adding reverse PIT, namely abandons after reverse PIT sets up.

Preferably, described recipient sets up reverse PIT and is specially:

When special interests bag arrives recipient, recipient sets up PIT, and name prefix is consistent with intermediate node handles, but PIT port numbers is recipient's local port number;

When packet arrives user B, searching PIT port is local port, can not continue forward content but be directly stored in local CS.

Preferably, described reverse PIT is that the incoming face in PIT and outgoing face is exchanged placement.

Above-mentioned explanation is only the general introduction of technical solution of the present invention, in order to better understand technological means of the present invention, and can be implemented according to the content of specification, coordinates accompanying drawing to be described in detail as follows below with preferred embodiment of the present invention.

Accompanying drawing explanation

Fig. 1 shows CCN protocol stack model;

Fig. 2 shows CCN packet format;

Fig. 3 shows CCN inter-node communication flow chart;

Fig. 4 shows the flow chart realizing content and push in CCN according to an embodiment of the invention.

Embodiment

For further setting forth the present invention for the technological means reaching predetermined goal of the invention and take and effect, below in conjunction with accompanying drawing and preferred embodiment, to a kind of content delivery method based on CCN its embodiment, feature and effect thereof of proposing according to the present invention, be described in detail as follows.In the following description, the not necessarily same embodiment that different " embodiment " or " embodiment " refers to.In addition, special characteristic, structure or feature in one or more embodiment can be combined by any suitable form.

Fig. 1 shows the model of CCN protocol stack.Protocol stack structure based on CCN is similar with the protocol stack structure based on TCP/IP, is all hourglass model.Wherein maximumly not to be both, to use Content chunk (content blocks) agreement to instead of IP agreement.From the angle of network, namely replace naming physical entity to numerical nomenclature in a network.In addition, built-in memory function in a network, is used for the packet of buffer memory process, in order to accelerate the response time of other user's access cache packets, can reduce the flow in network simultaneously.

CCN communication is driven by data consumer, and data can carry out the transmission of block level.The bag of two types is comprised: interest bag (Interest Packet) and packet (Data Packet) in CCN.Fig. 2 shows the packet format of CCN.Interest bag (Interest Packet) comprises and refers to content name (Content Name), for unique identification content; Selector (Selector), comprises some optional parameters, for determining the processing method of interest bag, and such as Scope=0, then interest bag can not forward to other application programs of this main frame, and Scope=1 then can not forward to the main frame of initiating interest bag; Random number (Nonce), for unique identification interest bag, avoids repetition.Packet comprises, and content name (Content Name), for unique identification content name; Signature (Signature), for unique identification content sources and content name; Signing messages (Signed Info), comprises the time, the information such as key, for arranging content parameters; Data (Data) refer to the data content of real transmission.Need the user of related content to send request to multiple directions by interest bag by node according to the FIB of self, the node receiving this request if any has the content that can meet this request, then send response data by packet to requesting node.This corresponding relation is based upon on the basis that identifies content, and namely each content has a concrete mark.The position of interest bag and packet has nothing to do, and on a broadcast medium, has the request of same content requirements can share identical content and Internet Transmission, thus saves Internet resources, improve network transmission efficiency.

The mark of content is exactly the address of CCN in fact.Namely this mark is structurized, usually be made up of several assembly (also component), wherein between each assembly by/separate by this structurized address, can utilize and be similar to that IP address prefix is machine-processed locates rapidly required information.Such as/catr.cn/videos/WidgetA.mpg/_v<timestampGrea tT.GreaT.GT/_s3, wherein catr.cn is the whole network identifiable design title, videos is content type, WidgetA.mpg is content name, _ v<timestamp> be the information, _ s3 such as version time is the information such as segmentation.

If the content name of interest bag (Content name) is the prefix of the content name (Content name) of packet, then represent that this packet meets request.Content name can dynamically generate, and namely allows there is not being applied in when receiving interest bag of this request content and produce this content temporarily.Be similar to, Dynamic Web, i.e. static content and dynamically generation mixing support.

Term Face(face) refer to interface CCN transponder being coupled to application or network.Face can based on hardware or software.Such CCN interface is called as Face can play differentiation effect with the interface (interface) as the physical network interface in router term to make them.

As bag arrival Face, carry out longest prefix match by utilizing content name and search, wherein will use three critical datas and complete forwarding (FIB, content caching, PIT).FIB(Forwarding information base, forwarding information base) be equivalent in IP agreement routing table, but allow multiple outlet, instead of be only limitted to one.Content caching (Content store) can use LRU(least recently used) tactful and life span (TTL, time to live) etc. access vector cache forward packet, use for other consumers, improve the hit rate of packet.PIT(Pending Interesting Table, interest table undetermined) for recording content name and the port numbers of the interest bag forwarded, thus allow the packet of response can arrive the requestor of its correspondence according to port numbers.When response interest packet utilize certain entry of PIT forward after or life span expire, this entry is deleted.

When Interest bag (interest bag) arrives a certain node, first according to interest bag matching content buffer memory, if there is the content matched, then utilize the content response request of coupling and abandon Interest bag; If there is no the content matched, then description is not buffered or cache-time expires and is replaced, now start to mate PIT, if there is the PIT entry of coupling, then illustrate other users may have requested same content not long ago, can PIT polymerization be carried out herein, namely in the corresponding entry of PIT, increase Face, and abandon Interest bag; If there is no the content matched, then according to interest bag longest prefix match FIB, arrive Face according to the Face(of all couplings except Interest wraps) forward Interest bag, if still there is not the Face matched, then abandon this Interest and wrap.

The process of data bag (packet) is relatively simple, when a data packet arrives, first to the Content Name(content name of packet) field carries out longest prefix match, first at Content Store(content caching) in mate, if there is the content of coupling, the content then returned is invalid content, and the interest bag of before asking be responded, therefore abandons this packet; If there is no the content of mating, then start in PIT, to continue coupling, if there is the entry of coupling, then the port numbers that content records from PIT is forwarded, be buffered in Content Store(content caching simultaneously), the entry of if there is no mating, then abandon this packet.

Fig. 3 shows CCN inter-node communication flow chart.Several intermediate nodes C may be there is between user A and content source B, for for purpose of brevity, in Fig. 3, exemplarily illustrate only an intermediate node C.Wherein user A also can be referred to as node A, and same content source B also can be referred to as Node B or user is B.As shown in 301, when user A needs request content, initiatively send interest bag; Intermediate node C receives after interest bag can inquire about CS(Content Store, content caching successively), PIT and FIB.If do not have the content that user A asks in CS, intermediate node C records the port numbers receiving interest bag on PIT; As illustrated at 302, intermediate node C forwards this interest bag according to FIB; Each interest is surrounded by a nonce(random number); Each CCN node, when receiving interest bag, will judge the title of interest bag, when receiving one with title but the interest bag of different nonce, and the port that CCN will add this interest bag and comes in PIT; If the interest bag title received is all identical with both nonce, then CCN node will abandon this repetition interest bag; As disclosed at step 303, first content source B searches the CS of oneself after receiving interest bag, if there is the content that user A asks in CS, then presses original route according to the port information of PIT record, as shown in step 304, turns round this content via intermediate node C.Meanwhile, copy of content can be buffered in local CS by the intermediate node C of content process.

The form of PIT entry is as shown in table 1 below, and wherein Face0 refers to the port that interest bag enters.

Interest name prefix	Incoming faces
		name	Face0

Table 1:PIT entry format

The form of FIB entry is as shown in table 2 below, and wherein Face1 refers to the port that interest is contracted out.

Interest name prefix	Outcoming faces
		name	Face1，Face2

Table 2:FIB entry format

Under normal circumstances, only have and initiatively send interest bag by user, could trigger and obtain corresponding contents.Such as, but a lot of application scenarios needs content to be directly pushed to user, present widely used microblogging, real-time speech communicating, large files transmission, stock, weather forecast etc.

A PIT path can be set up by sending the triggering of interest bag, when content needs to return by searching PIT path when returning in CCN.If user A needs the initiatively content initiated to user B to push, then need to set up between user A and user B that a PIT path makes that the content without user B request can be correct is pushed to user B.User A directly can search the propelling movement that CS carries out content, and without the need to starting to search CS receiving interest Bao Shicai.Correspondingly user B can allow to receive and store the content without oneself request.

In a specific embodiment of the present invention, user A sends a special interests bag, after intermediate node C between user A and user B receives special interests bag, interpolation PIT entry is revised PIT middle port direction, namely between user A and user B, directly set up a reverse PIT path, make not have requested content can forward according to reverse PIT path, thus without the need to the active request of user B, content just can directly be pushed to user B by packet from user A.

In a specific embodiment of the present invention, reverse PIT, namely exchanges placement the incoming face in normal PIT and outgoing face.By building reverse PIT, PIT " can be cheated ", then when propelling movement side user A has this content time, just can by this content active push to recipient user B.

In a specific embodiment of the present invention, the normal interest bag mentioned in scheme of the invention in addition refers to the interest bag not comprising specific fields " PIT ", and special interests bag refers to the interest bag comprising specific fields " PIT ", such as ccnx:/B/PIT/B/name/%FD%versionnumber/%pushnumber/n is special interests bag, and ccnx:/B/name/%FD%versionnumber/%pushnumber is then normal interest bag." PIT " is herein only exemplary explanation, can use other specific fields under the prerequisite not departing from design of the present invention.It should be noted that, due to the bag of be only interested in CCN bag and packet two type, in order to enrich the application of CCN in some scenes, specific fields can be added to be different from common interest bag and packet in CCN bag.In CCN, specific fields generally all refers to that interpolation one is similar to the field of " PIT " in interest bag name, making this interest bag can complete different functions, such as in video request-program process, " Video " field can be added to construct special interests bag in interest bag to optimize on-demand process.

Under normal circumstances (namely when the interest sent comprises specific fields PIT), user A sends interest bag to user B, can first inquire about CS at intermediate node C place and there is no buffer memory, if then inquire about in PIT PIT and there is not occurrence, start to set up PIT entry, suppose that interest bag arrives from the Face2 of intermediate node C and forwards from the Face1 of intermediate node C, the PIT entry of then adding at intermediate node C place is interest bag name and Face2(, and PIT entry is as shown in table 3 below under normal circumstances), then forward according to the Face1 port of FIB record after having added PIT, like this when content turns back to intermediate node C from user B, inquiry PIT is directly transmitted to user A from Face2, complete the process obtaining content.

Interest name prefix	Incoming faces
		ccnx:/B/name/%FD%versionnumber/%pushnumber	Face2

Table 3: PIT entry under normal circumstances

Reverse PIT refers to, when adding port, still suppose that interest bag arrives user B from the Face2 arrival of intermediate node C from Face1 forwarding herein by adding forwarding port Face1 instead of interest bag entry port Face2(in PIT entry), as shown in table 4 below in the PIT entry of C place interpolation.Like this when needs push content to user B from user A, then directly content can be forwarded from Face1 by the PIT arranged in advance through user C, make content can arrive user B, thus realize the technique effect pushing content.

Interest name prefix	Incoming faces
		ccnx:/B/name/%FD%versionnumber/%pushnumber	Face1

Table 4: PIT entry under inversion condition

The FIB entry of user A and intermediate node C is as shown in following table 5 and table 6:

Interest name prefix	Outcoming faces
		B	Face1

table 5: the FIB entry of user A

Interest name prefix	Outcoming faces
		B	Face1

Table 6: the FIB entry of user C

After establishing FIB entry as above, the interest bag issuing user B from user A correctly after searching FIB can be forwarded to Node B.

Fig. 4 flow chart realizing content and push in CCN according to an embodiment of the invention.Step 401, user A(i.e. the side of propelling movement A) construct special interests bag and send this special interests bag, the reason constructing special interests bag herein considers that the handling process of this interest bag and normal interest bag is different, consider that this special interests wraps in subsequent processes different with the handling process of normal interest bag, therefore in constructed interest bag can: 1), add content recipient B(user B) title present embodiment in be B, object be interest bag can by search FIB correct be routed to content recipient; 2), the burst quantity and initial burst number that need to push are described, large files has all carried out the burst of content in transmitting procedure, therefore needs to illustrate that the complete content of needs can push successfully by burst quantity and initial burst number in particular interest bag; 3), description name.In view of some consideration above, interest bag (Interest bag) form constructed is as follows:

ccnx:/B/PIT/B/name/%FD%versionnumber/%pushnumber/n

In Interest bag, each field meanings is as follows:

/ B/PIT/:B is as communication receiver, and " PIT " is as the detected field setting up reverse PIT

/ B/name:/B/name is the title of the content being about to be pushed to B in the CS of propelling movement side A.

/ pushnum:pushnum refers to the content starting segment number sent, and in pushing at large files, be all push from segmentation 0, therefore in large files pushes, pushnum is 0; Then as the case may be starting segment number is determined for other scenes.Application scenarios is transmitted as in the present embodiment with large files.

/ n:n is the quantity for setting up reverse PIT entry, and during large files transmits, A determines by the CS of inquiry oneself division number pushing content.

The assembly (component) of " %FD%versionnumber " this expression version number is optional.And the form of special interests bag can also be defined as follows: ccnx:/B/PIT/name/%FD%versionnumber/%pushnumber/n, because "/B " this component is just for route, the Face corresponding to user B can be inquired by longest prefix match when the interest started with "/B " wraps in inquiry FIB, what make that interest bag can be correct is routed to user B, therefore only can needing one "/B " in special interests bag, if like this, will only need to remove "/PIT " when receiving particular interest bag.

Step 402, resolves interest bag, and judges whether comprise specific fields in interest bag.

In a specific embodiment of the present invention, specific fields i.e. " PIT " field; The interest Bao Ze correspondingly including " PIT " field is called as special interests bag; And the interest Bao Ze not containing " PIT " field is called as normal interest bag.

The resolving of special interests bag is specific as follows:

User A and the intermediate node C between user A and user B receives the specific interest bag that user A sends, whether second component is " PIT " to utilize string matching to judge when resolving interest bag, judge whether thus " PIT " specific fields to be detected, if " PIT " specific fields do not detected, then continue to perform step 404, according to the flow processing interest bag shown in Fig. 3; If " PIT " specific fields detected, then continue to perform step 404, remove two compnent:/B above and/PIT and last component; Step 405, builds the individual new continuous print interest bag of n:

ccnx:/B/name/%FD%versionnumber/%pushnumber

ccnx:/B/name/%FD%versionnumber/%pushnumber+1

ccnx:/B/name/%FD%versionnumber/%pushnumber+2

ccnx:/B/name/%FD%versionnumber/%pushnumber+n-1；

The flow processing of this n interest bag and common interest bag is different, common interest bag is all directly forwarded after having searched forwarding port, and after establishing this n interest bag herein, the forwarding port of interest bag is searched according to normal flow process, then interest Packet forwarding port is added to (normal flow process adds the port that interest bag is come in PIT entry) in PIT entry, after having added PIT entry, do not need to forward this n interest bag, directly interest bag is abandoned.

The n built new interest comprises PIT character string, and this node really neither need to obtain this content, and the object building interest bag, just in order to create reverse PIT, makes the side of propelling movement A according to correct path, content can be pushed to recipient B.If forwarded by downward for interest bag one or more node, then may there is situation about original unwanted content being returned, waste Internet resources and may network congestion be caused.For example: if the side of propelling movement A needs n block content to be pushed to recipient B, then need to build n PIT entry of mating with content blocks at intermediate node C place, the content at A place just can be made pushed, therefore the interest bag that can build n at C Nodes is for building reverse PIT, but C node does not need to get content, therefore also need not forward this n interest bag.

Specific implementation process is as follows:

N the interest bag according to building determines that the entry needing to add in PIT is:

ccnx:/B/name/%FD%versionnumber/%pushnumber；

ccnx:/B/name/%FD%versionnumber/%pushnumber+1；

ccnx:/B/name/%FD%versionnumber/%pushnumber+2；

ccnx:/B/name/%FD%versionnumber/%pushnumber+n-1。

Step 406, starts to realize port reverse, and adds reverse port, complete the interpolation of reverse PIT entry after with the addition of interest bag entry.Record interest Packet forwarding port Forwarding face, and Forwarding face is added in newly-established PIT entry, because interest Packet forwarding direction is consistent with the direction that content pushes, that is interest Packet forwarding direction and content push direction is all from user A to user B, path and the port of middle process are all the same, so the forwarding port at place i.e. user A are pushed to the forwarding port of the content of user B.Add correct port in PIT entry after, when user A pushes content to user B, content can be made by the reverse PIT of inquiry, content can be correctly forwarded to target node b (that is, recipient B) at user A and intermediate node C place.The reverse PIT form of intermediate node is as follows: (wherein, namely Face1 is that also forwarding face, A are as propelling movement side for the outgoing face of interest bag, and B is as recipient, but adding as incoming face when adding PIT, realizing the reverse of port thus).

Interest name prefix

Incoming faces

Table 7: the reverse PIT form of intermediate node

Intermediate node also needs special interests bag to continue to forward to next node except adding reverse PIT when process special interests bag, mainly consider that user B also needs to process accordingly after receiving special interests bag, make content can by correctly buffer memory when arriving user B, therefore special interests wrap in intermediate node all needs to forward until content reception stops forwarding just now.And n the interest bag built when adding reverse PIT is not forwarded, namely abandon after reverse PIT sets up.When packet is forwarded to destination node B along reverse PIT, if do not carry out special processing, not requested data can be abandoned according to CCN agreement B and not carry out buffer memory (main cause is that PIT entry can be searched by content arrival user B place, if there is no mates PIT and then directly abandons).

For avoiding packet to be directly deleted at user B place, in a specific embodiment of the present invention, step 407, when special interests bag arrives user B, user B sets up PIT, and name prefix is consistent with intermediate node handles, is user B local port number unlike PIT port numbers herein.When packet arrives user B, searching PIT port is local port, can not continue forward content but be directly stored in local CS.PIT entry for user B place sets up has been shown in table 8.

Table 8: the reverse PIT form of content recipient

In another embodiment of the present invention, for avoiding packet to be directly deleted at Node B place, CCN strategy can be revised further, make content arrive node time do not search PIT, directly by content caching in local CS.

In order to user A can be made, the CS content of oneself is gone out according to the port repeat recorded in PIT, step 408, after reverse PIT establishes, node A carrys out triggering lookup CS(by the ccngetfile ccnx:/B/name file got in local CS please supplement particular content), ccngetfile order is that under CCN emulation platform gets file command, make user can get content in local CS or other user CS to leave this locality in by performing this order, but this operation of getting file remains by interest bag, packet completes, use during ccngetfile order and initiatively can send multiple interest bag to content source (also comprising local CS) according to the burst situation of file, then obtain multiple content segments from content source to return and leave this locality in.Herein, when using ccngetfile ccnx:/B/name order at node A place, owing to not comprising " PIT " specific fields in " ccnx:/B/name ", therefore node A can send request the normal interest bag of content to the local port of oneself, this interest bag no longer will comprise " PIT " specific fields, the CS that node A first looks into oneself at the interest Bao Shihui that process receives finds matching content, then searches PIT and mates entry and port repeating content recorded from PIT; Step 409, owing to being cached with content in the side of propelling movement CS, and has established PIT entry in advance, searched CS find matching content after just can directly according to set up PIT to carry out the forwarding of content, carry out the propelling movement of trigger content thus.Step 410, content is transmitted according to the PIT path established at intermediate node place, because recipient also has specific PIT entry (port is local face) or direct cache policy after arriving recipient, recipient can push the content of coming by direct cache user A in a word, can by the packet capturing of packet capturing software or directly to use ccndumpnames order to check CS content learns recipient B buffer memory content, when using ccngetfile triggering lookup CS at user A place, open the packet capturing software at user B place, start to grab the bag through user B place, and analyze packet capturing result, can see in packet capturing and show from node C to the n of user B content segments, illustrate that content has successfully been pushed to user C by user A, next need to check that whether user C is by content caching, use ccndumpnames to check that the content in CS also can see n content segments at user C place, then illustrate that user C is successfully by content caching.In addition, if in order to verify that content pushes process and whether occurs that the situation of packet loss can use ccngetfile ccnx:/B/name at user B place, if user B place successfully can get content, then description pushes successfully.

By technical scheme disclosed in this invention, content propelling movement person is initiating communication initiatively, just content directly can be pushed to without the need to user's request and receive user, without the need to repeatedly mutual, by the triggering of a special interests bag, the reverse propelling movement path of multiple content can be set up, greatly reduce communication delay and link load.The present invention can be applied in numerous application scenarios, such as often use now make a phone call, microblogging, large files transmission, stock, weather forecast etc., enriched the practical application of CCN network.

The above, it is only preferred embodiment of the present invention, not any pro forma restriction is done to the present invention, although the present invention discloses as above with preferred embodiment, but and be not used to limit the present invention, any those skilled in the art, do not departing within the scope of technical solution of the present invention, make a little change when the technology contents of above-mentioned announcement can be utilized or be modified to the Equivalent embodiments of equivalent variations, in every case be the content not departing from technical solution of the present invention, according to any simple modification that technical spirit of the present invention is done above embodiment, equivalent variations and modification, all still belong in the scope of technical solution of the present invention.

Claims (7)

1., based on a content delivery method of CCN, it is characterized in that:

Propelling movement side's structure special interests bag also sends this special interests bag;

Intermediate node resolves interest bag, and judges whether comprise PIT specific fields in interest bag;

If intermediate node detects PIT specific fields, then revise PIT entry;

Intermediate node amendment port, sets up reverse PIT;

Intermediate node according to FIB route by described special interests Packet forwarding to next node;

Recipient sets up reverse PIT;

Propelling movement side triggers interest bag inquiry PIT and mates entry;

The port repeating that content records by propelling movement side from PIT;

If described intermediate node detects PIT specific fields, then revise PIT entry and comprise further:

Remove the assembly of PIT flag bit and last expression PIT quantity above;

Build the continuous print interest bag that several are new;

Search the forwarding port of interest bag, interest Packet forwarding port is added in PIT entry;

After having added PIT entry, do not forward this several interest bags, directly interest bag is abandoned;

Described recipient sets up reverse PIT and is specially:

When special interests bag arrives recipient, recipient sets up PIT, and name prefix is consistent with intermediate node handles, but PIT port numbers is recipient's local port number;

When packet arrives user B, searching PIT port is local port, can not continue forward content but be directly stored in local CS;

Described reverse PIT is that the incoming face in PIT and outgoing face is exchanged placement.

2. method according to claim 1, is characterized in that:

If the result judging whether to comprise in interest bag PIT specific fields described is no, then continue process according to normal CCN flow process.

3. method according to claim 2, is characterized in that:

Described normal CCN flow process is specially:

When requesting party needs request content, initiatively send interest bag; Intermediate node understands query contents buffer memory (CS), PIT and FIB successively after receiving interest bag;

If do not have the content that requesting party asks in CS, intermediate node records the port numbers receiving interest bag on PIT;

Intermediate node forwards this interest bag according to FIB; Each interest is surrounded by a random number (nonce); Each CCN node, when receiving interest bag, judges the title of interest bag, and when receiving one with title but the interest bag of different nonce, CCN adds the port that this interest bag is come in PIT; If the interest bag title received is all identical with both nonce, then CCN node will abandon this repetition interest bag;

Content source searches the CS of oneself after receiving interest bag, if there is the content that requesting party asks in CS, then press original route according to the port information of PIT record; This content is turned round via intermediate node;

Copy of content is buffered in local CS by the intermediate node of content process.

4., according to the method for claim 1 or 3, it is characterized in that:

Content recipient title in the special interests bag constructed, need the burst quantity that pushes and

One or more in initial burst number and content name.

5. method according to claim 4, is characterized in that:

The port repeating that content records by described propelling movement side from PIT comprises further:

Search after CS finds matching content, directly carried out the forwarding of content according to the PIT set up.

6. method according to claim 5, is characterized in that:

Described special interests Packet forwarding comprises to next node according to FIB route by described intermediate node further:

Intermediate node forwards special interests bag, until the reception arriving content stops forwarding just now.

7. method according to claim 6, is characterized in that: intermediate node does not forward for several interest bags built when adding reverse PIT, namely abandons after reverse PIT sets up.