CN102647357A

CN102647357A - Context routing processing method and context routing processing device

Info

Publication number: CN102647357A
Application number: CN2012101185716A
Authority: CN
Inventors: 汪军; 许欣
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2012-04-20
Filing date: 2012-04-20
Publication date: 2012-08-22
Anticipated expiration: 2032-04-20
Also published as: CN102647357B; WO2013155979A1

Abstract

The invention provides a context routing processing method, network element equipment and a network server. The process context routing method includes: receiving context access information reported by context routing devices in a local area by the network server; computing frequency of historic context access according to context addressing in the context access information, and adjusting a context routing list according to the frequency; and issuing the context routing table adjusted to all context routing devices in the local area. By the context routing processing method, conflict between context flow transmission efficiency and cache hit ratio can be eliminated, so that higher integral transmission performance can be realize by least cost and cache hit ratio is increased.

Description

A kind of contents processing method for routing and device

Technical field

The present invention relates to the content network correlation technique, particularly relate to a kind of contents processing method for routing and device.

Background technology

According to Cisco (Cisco) VNI (Visual Network Index; Visualization network index) statistical forecast; Flow in the internet traffic more than 90% all be Web Data (data) but, the duplicate contents of file-sharing, video class; These flows adopt the pattern of buffer memorys, forwarding more efficient, and the present networks support is mode end to end, under existing Internet streaming measure feature, are poor efficiencys.

In in the past 20 years; There have been some technology to be used to improve the transmission of these content flows; Such as the website mirroring of the nineties, the Web Cache (cache memory) that occur the end of the nineties, CDN (the Content Delivery Network that introduced later in 2000; Content distributing network) all be from the nearer place of end user with content caching; Reduce message repeating on the backbone and transmit, reduced on the one hand content delivery time delay, improved user experience, also reduced the provider backbone expense on the other hand.But these technology all are the application layer technology on the Internet, are optimized to certain applications, specific website, cannot change most internet traffics mode end to end.

Advanced several years; Academia begins one's study the Internet is transform as with the content delivery is the buffer memory-forward mode at center; More famous project comprises DONA (Data Oriented Network Architecture; The data-oriented network architecture), PSIRP (Publish-Subsrible Internet Routing Paradigm, distribution subscription formula the Internet route matrix), NDN (Named Data Networking, named data network; Referring to http://www.named-data.net/) etc.; The common trait of these frameworks is to change the basic primitive of communicating by letter between the main frame into connectionless content/data from the form of connection-transmission/reception message of original IP to read/subscribe to, and the network equipment is provided with content caching, and will resolve the content that main frame sends and read request; If hit local cache then return results immediately, otherwise continue route in network.The network that clearly proposed that these frameworks have is realized form, adopts the content router networking such as NDN, adopts Routing Protocol exchanging contents route; Form the network of a stratification; The technology that has does not indicate the network form, but it has selected flattening addressing mode (such as DONA), and route is such as converging like this; Can only adopt the form of server cluster or concentrated catalogue, can't adopt router to carry out networking.

Adopt the content network of server cluster form; Its advantage is a networking flexibility; The cache cluster that can form random scale, shortcoming are that server transmission message efficient is not high, and the speed that reach router needs a large amount of servers; Energy consumption and integrated level all are problems, and be especially all the more so for the basic network that needs carry all flows of the Internet.Adopt the content network of router form, its advantage is that forwarding speed is fast, and port density is high; Shortcoming is that memory capacity is limited; In addition its transmit at a high speed relied on to search memory expensive and power consumption high, the routing list capacity of support is limited, can't carry out fine-grained content routing scheduling.The internet content long tail effect is obvious on the other hand; It is generally acknowledged that meeting Zipf (Qi Pufu distribution) distributes; Be that visiting frequency does, if adopt buffer memory, required buffer memory capacity is mentioned and is index and rises along with hit rate; Adopt router networking content caching capacity to be limited by the equipment framework, totally reach the i.e. difficulty very of 50% cache hit rate.According to the unduplicated content source total amount of user capture is that 1E (10^18) byte is calculated (according to the statistics of Google (Google); The Internet total capacity promptly reached the 5E byte in 2008); Zipf profile parameter=0.8; The Cache hit rate reaches 50% need be near the buffer memory capacity of 30PB (1P=10^15), this head and shoulders above the router device buffer memory that can provide.

Summary of the invention

The technical problem that the present invention will solve provides a kind of method and network element device, webserver of contents processing route, to solve the contradictory problems between content flow forward efficiency and the cache hit rate.

In order to solve the problems of the technologies described above, the invention provides a kind of method of contents processing route, comprising:

The webserver receives the content access information that the content routing device in this territory reports;

According to the frequency of the content of the content addressing computation history in said content access information visit, according to said frequency adjustment content routing table;

Adjusted content routing table is handed down to all the elements routing device in this territory.

Further, said method also has following characteristics:

Said content is addressed to the address of the coding form of content identification prefix, and the said webserver, comprising according to said frequency adjustment content routing table according to the historical visiting frequency of the calculating of the content addressing in said content access information corresponding content:

The said webserver calculates the historical visiting frequency of corresponding content according to the content identification prefix;

The route of the content of the appointment number that historical visiting frequency is the highest is revised as the sensing local cache, and the route of the content of the appointment number that historical visiting frequency is minimum is revised as points to corresponding router or corresponding content source facility.

Further, said method also has following characteristics:

The said webserver merges processing to content identification prefix identical in the said content routing table.

Further, said method also has following characteristics: also comprise:

After the said webserver receives the route table items of foreign lands network, in said content routing table, add the route table items of said foreign lands network, the route of this route table items is pointed to the designated equipment in the network of foreign lands.

Further, said method also has following characteristics: also comprise:

After the said webserver receives the access to content request of content routing device, the inquiry local cache, if hit, then the content-data with local cache returns to this content routing device; If miss, then inquire about said content routing table, carry out route according to the next-hop device that hits.

In order to address the above problem, the present invention also provides a kind of webserver, comprising:

First module is used to receive the content access information that the content routing device in this territory reports;

Second module is used for the frequency according to the content of the content addressing computation history of said content access information visit, according to said frequency adjustment content routing table;

Three module is used for adjusted content routing table is handed down to all the elements routing device in this territory.

Further, the above-mentioned webserver also has following characteristics:

Said second module specifically is used for calculating according to the content identification prefix the historical visiting frequency of corresponding content; The route of the content of the appointment number that historical visiting frequency is the highest is revised as the sensing local cache; The route of the content of the appointment number that historical visiting frequency is minimum is revised as points to corresponding router or corresponding content source, also is used for the identical content identification prefix of said content routing table is merged processing.

Further, the above-mentioned webserver also has following characteristics: also comprise:

Four module after being used to receive the route table items of foreign lands network, adds the route table items of said foreign lands network in said content routing table, the route of this route table items is pointed to the designated equipment in the network of foreign lands.

The 5th module, after being used to receive the access to content request of content routing device, the inquiry local cache, if hit, then the content-data with local cache returns to this content routing device; If miss, then inquire about said content routing table, carry out route according to the next-hop device that hits.

In order to address the above problem, the present invention also provides a kind of method of contents processing route, comprising:

The content routing device obtains content routing table from the network center in affiliated territory;

After said content routing device receives the access to content request, the inquiry local cache, if hit, then the content-data with local cache returns to the user; If miss, then inquire about said content routing table, carry out route according to the next-hop device that hits.

Further, said method also has following characteristics: after the said content routing device contents processing access request, also comprise:

Said content routing device is taken a sample to the access to content solicited message of history, and the access to content solicited message of taking a sample is reported said network center, and said access to content solicited message comprises content addressing information.

Further, said method also has following characteristics: said next-hop device comprises:

Designated store equipment, content source facility or the next hop router of said network center.

In order to address the above problem, the present invention also provides a kind of content routing device, comprising:

First module is used for obtaining content routing table from the network center in affiliated territory;

Second module, be used to receive the access to content request after, the inquiry local cache, if hit, then the content-data with local cache returns to the user; If miss, then inquire about said content routing table, carry out route according to the next-hop device that hits.

Further, the foregoing routing device also has following characteristics: also comprise,

Three module is used for the access to content solicited message of history is taken a sample, and the access to content solicited message of taking a sample is reported said network center, and said access to content solicited message comprises content addressing information.

Further, the foregoing routing device also has following characteristics: said next-hop device comprises:

In order to address the above problem, the present invention also provides a kind of network system, comprising: the above-mentioned webserver and a plurality of above-mentioned content routing device.

To sum up, the present invention provides a kind of method and network element device, webserver of contents processing route, can solve the contradiction between content flow forward efficiency and the cache hit rate, makes minimum cost realize higher whole forwarding performance and improves cache hit rate.

Description of drawings

Fig. 1 is the network architecture diagram of the embodiment of the invention;

Fig. 2 is the sketch map of the content routing device of the embodiment of the invention;

Fig. 3 is the sketch map of the webserver of the embodiment of the invention;

Fig. 4 is the flow chart of method of a kind of contents processing route of the embodiment of the invention;

Fig. 5 is the flow chart of a kind of content router access network of the embodiment of the invention;

Fig. 6 is the flow chart of a kind of content route of the embodiment of the invention;

Fig. 7 is the flow chart of the cross-domain content route cooperation of the embodiment of the invention;

Fig. 8 is the flow chart of CRDS content routing statistics, calculating and the merging of the embodiment of the invention.

Embodiment

For making the object of the invention, technical scheme and advantage clearer, hereinafter will combine accompanying drawing that embodiments of the invention are elaborated.Need to prove that under the situation of not conflicting, embodiment among the application and the characteristic among the embodiment be combination in any each other.

Fig. 1 shows a kind of network architecture of the embodiment of the invention; Comprise access to content client (for example, PC, portable terminal, panel computer etc.), router (CR), content caching cluster (CCS), content routing policy policy server (CRDS) in one of them autonomous territory.Can pass through CRDS exchanging contents routing iinformation in a plurality of autonomous territories.

At network edge content router (CR) is set, router uses the built-in storage of equipment that first order content caching is provided, when not hitting built-in buffer memory through the content requests of content router, and next jumping that its query contents routing table decision is transmitted.

Content router can be special network element device, also can be existing to move, add the equipment that the content caching function modifications forms on the fixed network couple in router, common ip router.

In network center the storage cluster system (CCS) based on server architecture is set, capacity is provided with according to overall target cache hit rate; Simultaneously in network center content routing policy policy server (CRDS) is set also, it is responsible for the content routing table of control content router, and collects the content caching information of content stores group system in this territory.

Realize cooperating between multiple domain like need, then be responsible for the content routing decision server communication in its territory and exchange route by content routing decision server.

Fig. 2 is the sketch map of the content routing device of the embodiment of the invention, and is as shown in Figure 2, and the network element device of present embodiment comprises:

The network element device of present embodiment can also comprise:

Wherein, said next-hop device comprises:

Like this, the content routing device is first to jump content caching, its buffer memory the hottest partial content in the network, generally can accomplish the cache hit rate of 20-40% to have the efficient transfer capability of router simultaneously again.

Fig. 3 is the sketch map of the webserver (like above-mentioned CRDS) of the embodiment of the invention, and as shown in Figure 3, the webserver of present embodiment comprises:

Wherein, said second module specifically is used for calculating according to different content identification prefixs the historical visiting frequency of corresponding content; The route of the content of the appointment number that historical visiting frequency is the highest is revised as the sensing local cache, and the route of the content of the appointment number that historical visiting frequency is minimum is revised as points to corresponding router or corresponding content source.

In a preferred embodiment, the said webserver can also comprise:

Fig. 4 is the flow chart of method of a kind of contents processing route of the embodiment of the invention, and is as shown in Figure 4, comprises following step:

Step 101, content routing device obtain content routing table from the network center in affiliated territory;

Active and CRDS contact when CR is linked into network, CRDS issues content routing table to this CR, and this routing table can comprise:

1), this territory CCS cache contents, or signatory domain name (its route is directly pointed to local CCS);

2), the statistics be indicated as the visit focus the website domain name, its route is pointed to local CCS.

3), other content route is pointed to the content router or the content source of next jumping.

Step 102, CR contents processing access request;

Particularly, after the content routing device receives the access to content request, the inquiry local cache, if hit, then the content-data with local cache returns to the user; If miss, then inquire about said content routing table, carry out route according to the next-hop device that hits.

After step 103, the CR contents processing access request, can certain strategy visit information is taken a sample and report CRDS;

Sampling frequency is selected to want dependable flow CRDS not to be caused too high performance pressure, also can guarantee the validity of statistics, such as the visit of sampling x%, x=1～10 (span that is x is between 1 to 10).

Step 104, the CRDS visit information that sampling reports according to CR calculate the visiting frequency of content source, according to the content routing table of visiting frequency adjustment CR;

The route that forward and original route is directly pointed to content source to the visiting frequency rank is adjusted into points to this territory CCS, and CCS can prefetching content or cache contents as required, guarantees that the focus content can hit at this territory CCS; Simultaneously unexpected winner content route is directly pointed to content source or next jumping content router.

Step 105, CRDS is handed down to all the elements routing device in this territory with adjusted content routing table.

As above architecture and method through the embodiment of the invention can guarantee:

Can the buffer memory of the buffer memory of CR and CCS be regarded as the buffer memory capacity of overall system, this capacity can be benefited from the distributed server cluster technology, and capacity is enough big, thereby guarantees the enough cache hit rates of internet content visit that Zipf distributes.

CR first jumps content caching, its buffer memory the hottest partial content in the network, generally can accomplish the cache hit rate of 20-40% to have the efficient transfer capability of router simultaneously again.

The content route of CR is controlled by CRDS; And the latter can be according to operator content management strategy and real-time sampling statistical computation content route; The flow buffering hit rate that can guarantee to be routed to CCS is enough high, and (this part visit basically can Cache Miss (cache miss) and the flow that causes is circuitous and take a large amount of CCS disposal abilities through CCS also to avoid the unexpected winner access to content simultaneously.

Primary Calculation under existing internet content model, is provided with the buffer memory (10 of internet data total amount about 3% ¹⁷The Bytes order of magnitude) just can reach cache hit rate about 70%; That is to say that 30% visit still can Cache Miss, for CCS, equal the complete break-through of this flow of 30%; And (low more words just need be provided with more CCS because the CCS network site is higher relatively; Construction cost is higher), the circuitous path on existing IP network is also longer, causes the bandwidth cost to increase.Therefore, make the flow of this script Cache Miss can need not to make a circulation among the present invention, thereby further provide cost savings through CCS.

In the embodiment of the invention; The content address of the necessary perceived content visit of network; Therefore design a kind of access to content agreement, the content addressing in the access to content agreement is the address of a prefix code form, such as is a URL (Uniform/Universal Resource Locator; URL) the content addressing of form can be converged to guarantee its route.

Header promptly is the fullpath of content; Such as the content addressing form that is similar among the NDN; Like the content:example.com/path/xxx.ext/s_num form; Wherein s_num handles big media file and the slice number that designs for ease, and this content name also can be addressed directly to final content source, can obtain data from content source after making things convenient for content route network Cache Miss.This addressing form is layering simultaneously, conveniently carries out converging of route, can converge the route that becomes an example.com such as example.com/a, example.com/b, is issued to the total clauses and subclauses of content route of CR with minimizing.

Wherein, CR is positioned at the edge, adopts router, has at a high speed and transmits ply-yarn drill and local built-in high-speed cache, and for the client access request of receiving, it at first searches local cache, and route is carried out according to content routing table in miss back.Because be limited by the restriction of equipment volume, power consumption and high speed forwarding interface, built-in buffer memory capacity is often limited, mainstream technology can reach several TB (byte) (10 at present ¹²Byte).

CCS is positioned at the center of network; As required; It also can adopt distributed computing technology to be deployed in a plurality of geographical position, but adopts the server cluster technology generally, and the present mainstream technology of buffer memory capacity can arrive number TB/ server; The total big I of cluster reaches tens thousand of station servers and storage facility, and the buffer memory total capacity can reach several PB (10 ¹⁵Byte, petabyte) to tens of PB (10 ¹⁵Byte) magnitude.The long-tail distributed model of internet content has also determined the hottest content can use less buffer memory (the built-in buffer memory of CR) to realize valid cache, and the buffer memory that remaining content must the above order of magnitude of the such PB of CCS just can reach certain cache hit rate.

CRDS is positioned at the center of network, equally also can adopt the distributed deployment pattern, and it is responsible for controlling the content routing table of CR, and the main information source that CRDS generates the CR content routing table comprises:

1, the predefined cache policy of operator carries out buffer memory such as the overseas website to hot topic;

2, the signatory content sites of operator, operator is responsible for the content distribution of these content sites;

3, the content of buffer memory among the local CCS;

4, visit hot statistics.

But, consider that CR is a router platform, its routing table often adopts the such particular device storage of TCAM; Cost and power consumption are very high, and capacity is very limited, and main flow router TCAM capacity arrives hundreds of megabits tens of million at present; If be used to store the content addressing of text URL form, a route table items can reach bytes up to a hundred, and amounting to into bit is exactly hundreds of bits; Therefore; Contents table the best is to be no more than 1,000,000, so CRDS must carry out route assemblage when carrying out routing decision, guarantees that the route total amount is in the disposal ability scope of CR.

In the embodiment of the invention in order to guarantee that cold access to content flow made a circulation without CCS as far as possible; Adopt CRDS to control the CR routing table fully; Simultaneously in order to adapt to the variation of content temperature, CRDS needs carry out hot statistics to access to content, has also increased unnecessary processing expense and flow undoubtedly and makes a circulation but let all-access all pass through CRDS; The embodiment of the invention adopts the mode of abstract statistics; Be that CR reports visit data according to the sampling prescription that CRDS issues, such as the Cache Miss data of getting 2% at random, or 1% all-access information.

Fig. 5 is the flow chart of a kind of content router access network of the embodiment of the invention, and present embodiment may further comprise the steps:

Step 201:CR starts, through the auxiliary content routing policy policy server of finding of mechanism such as human configuration or DHCP, DNS;

Step 202:CR is connected with CRDS, reports node state and the ability of oneself, wherein possibly comprise information such as port status, buffer memory capacity;

Step 203:CRDS has generated the content routing table that presets according to existing operator content buffer memory, distribution policy and this territory content caching focus statistics information; The route of distribution in advance, buffer memory and focus content is directly pointed to this territory CCS, and perhaps unconcerned content route is pointed to other CR or content source in other unexpected winner;

Step 204:CRDS gives CR with routing table and access to content sampling rule downloading.

Fig. 6 is the flow chart of a kind of content route of the embodiment of the invention, and present embodiment may further comprise the steps:

Step 301: client is sent content requests, and request address is a.com/b/l.rmvb;

Step 302:CR receives that request back inquiry local cache is miss, table of query and routing then, and routing table is pointed to next and is jumped CR or content source;

Step 303:CR transmits content requests and jumps CR or content source to next;

Step 304: next jumping CR or content source are returned the content of request;

Step 305: whether said CR determines this content of buffer memory according to the buffer scheduling strategy;

Step 306: said CR returns to content the client of request;

Step 307: said CR takes a sample to access to content according to the sampling rule that issues and reports CRDS, comprises in the reporting information: content addressing, Cache Miss/Hit (cache miss/hit);

Step 308:CRDS adds up, sorts the visit situation of each content name according to the reporting information of repeatedly taking a sample of a plurality of CR, and the step of going forward side by side carries out the prefix route and merges, and finds that a.com/b path access frequency is comparatively forward;

Step 309:CRDS informs that CCS carries out buffer memory to the content in a.com/b path;

Step 310:CRDS issues route table items to CR, and the route of a.com/b is pointed to this territory CCS;

Step 311: client is initiated the content requests of a.com/b/2.rmvb once more;

Step 312:CR is Cache Miss still, inquires about local routing table again, and this list item has pointed to this territory CCS.

Step 313-315:CCS inquires about local cache, if existing then directly return, otherwise to the content source request content.Buffer memory has the reason of 2.rmvb to be among the CCS in this step:

1), CCS adopts prefetch policy;

2) this content that, other terminal access arranged.

Step 316-317:CCS returns to the content of request the client of request through CR.

Fig. 7 is the flow chart of the cross-domain content route cooperation of the embodiment of the invention, may further comprise the steps:

Step 401: the content distribution of c.com is responsible in territory 2, and local policy determines and cooperate in territory 1;

Step 402: the CRDS in territory 2 is to the CRDS in territory 1 announcement c.com route table items;

Step 403: the CRDS in territory 1 issues the route table items of c.com and gives the CR that is controlled, and its route table items is pointed to the CCS in territory 2;

Step 404: the client-requested c.com related content in territory 1 issues a request to and reaches CR;

Step 405: the CR inquiry local cache Cache Miss in territory 1, the result points to territory 2;

Step 406-407: said CR transmits request to the CCS in territory 2, and the latter returns the content of request;

In this step, the CCS address that directly do not stick one's chin out also can be selected in territory 2, but adopts the request of the CR acceptance region 1 of an intercommunication, and this does not influence basic principle of the present invention.

Step 408: whether the CR in territory 1 determines this content of buffer memory according to the buffer scheduling strategy, and content is returned to the client of request;

Step 409: said CR reports CRDS according to the sampling strategy, in order to follow-up decision.

Fig. 8 is the flow chart of CRDS content routing statistics, calculating and the merging of the embodiment of the invention, and concrete steps are following:

Step 501: beginning;

Step 502:CRDS receives that access to content sampling reports, comprising: whether content identification and buffer memory information such as hit;

Step 503 is that keyword upgrades content corresponding visit statistical counting with this content identification;

Step 504 merges statistics according to different length content identification prefix, and ordering;

Such as; Content www.a.com/a/1.jpg, www.a.com/a/2.jpg, www.a.com/b/1.doc visit respectively 4,6,10 times; Then can be merged into www.a.com/a/ visit 10 times, www.a.com/b/ visit 10 times further is merged into www.a.com visit 20 times;

Step 505: prefix length is respectively 1,2,3 prefix and sorts, get the forward and nonoverlapping some route prefix of rank respectively; Whether the information of hitting is carried out further optimum decision to CRDS according to buffer memory simultaneously; Like overwhelming majority visit in some content prefixs all is the content router cache hit; The expression content router buffer memory the overwhelming majority these prefix contents; Then CRDS can select this partial content prefix is pointed to local cache, and local cache is the data of this content prefix of buffer memory not also, to save buffer memory capacity.Certainly, CRDS also can determine the information of whether not hitting with reference to buffer memory.

In the present embodiment, prefix length is meant the segmentation number of content identification, is 1 such as the prefix length of www.a.com, and www.a.com/a/ length is 2, and the www.a.com/a/c prefix length then is 3.

In the present embodiment, getting prefix length and be 1,2,3 mainly is consideration from prefix quantity, in the real network if the prefix negligible amounts then can be got longer prefix as routed keyword.

Step 506: on the basis of foregoing route prefix, the content prefix in conjunction with the necessary buffer memory of carrier policy requirement generates routing table, and above prefix is pointed to CCS in this routing table, and other prefix or default route point to next jumping CR or directly point to content source.

Step 507: the new route table items that will generate is handed down to CR;

Step 508: finish.

One of ordinary skill in the art will appreciate that all or part of step in the said method can instruct related hardware to accomplish through program, said program can be stored in the computer-readable recording medium, like read-only memory, disk or CD etc.Alternatively, all or part of step of the foregoing description also can use one or more integrated circuits to realize.Correspondingly, each the module/unit in the foregoing description can adopt the form of hardware to realize, also can adopt the form of software function module to realize.The present invention is not restricted to the combination of the hardware and software of any particular form.

More than be merely the preferred embodiments of the present invention; Certainly; The present invention also can have other various embodiments; Under the situation that does not deviate from spirit of the present invention and essence thereof, those of ordinary skill in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims

1. the method for a contents processing route comprises:

2. the method for claim 1 is characterized in that:

3. method as claimed in claim 2 is characterized in that:

4. the method for claim 1 is characterized in that: also comprise:

5. like each described method of claim 1-4, it is characterized in that: also comprise:

6. webserver comprises:

7. the webserver as claimed in claim 6 is characterized in that:

8. the webserver as claimed in claim 6 is characterized in that: also comprise:

9. like each described webserver of claim 6-8, it is characterized in that: also comprise:

10. the method for a contents processing route comprises:

11. method as claimed in claim 10 is characterized in that: after the said content routing device contents processing access request, also comprise:

12. like claim 10 or 11 described methods, it is characterized in that: said next-hop device comprises:

13. a content routing device comprises:

14. content routing device as claimed in claim 13 is characterized in that: also comprise,

15. like claim 13 or 14 described content routing devices, it is characterized in that: said next-hop device comprises:

16. a network system comprises: like each described webserver of claim 6-9 and a plurality of like each described content routing device of claim 13-15.