6,073,175
`[11] Patent Number:
`[19]
`United States Patent
`
`Tavs et al.
`[45] Date of Patent:
`Jun. 6, 2000
`
`USOO6073175A
`
`[54] METHOD FOR SUPPORTING DIFFERENT
`$513:LiEGIEJEC‘EIEIJTSEIgTAIEEgEVfiETISISISING
`
`OTHER PUBLICATIONS
`Top 10 approach to prefetching on the Web, Markatos et al.,
`ICS publication, pp. 1—15, Aug. 1996.
`
`[75]
`
`Inventors: John Edward Tavs, Cary, N.C.; Dinesh
`Chandra Verma, MillWOOd, N.Y.
`
`Primary Examiner—Zuni Maung
`Attorney, Agent, or Firm—Whitham, Curtis & Whitham
`
`[73] Assignee:
`
`International Business Machines
`Corporation, Armonk, NY
`
`[21] APP1~ N03 09/067,509
`.
`.
`Apr. 27’ 1998
`Flled'
`[22]
`Int. Cl.7 ...................................................... G06F 13/00
`[51]
`[52] US. Cl.
`............................................. 709/226, 709/240
`[58] Field Of Search ..................................... 709/226, 240,
`709£29, 203’ 219
`
`[56]
`
`References Cited
`
`US PATENT DOCUMENTS
`4/1995 Oren et a1.
`.............................. 395/600
`5,408,655
`10/1997 Baker et a].
`...... 395/609
`5,678,041
`
`8/1998 Davis et a1.
`...... 709/224
`5,796,952
`10/1998 Nielsen ................ 709/233
`5,826,031
`
`........................... 707/2
`5,848,407 12/1998 Ishikawa et al.
`
`ABSTRACT
`[57]
`A method for classifying different pages accessed by a
`web-browser into different service-levels on a granularity
`finer than that of the connection. The method augments each
`edge device With two applications, a Client-Proxy and a
`Server-Proxy. The Client-Proxy obtains identifying infor-
`mation from the client’s request, and the obtain PICS
`labelling information from a label referee. This information
`is used to obtain a service level from an LDAP based SLA
`directory, and this service level information is then imbed-
`ded along With a unique identifier for the network operator
`organization in the HTTP header request Which is trans-
`ferred to the Server-Proxy. The Server-Proxy then strips the
`header containing the PICS information from the request
`and forwards the request to the sewer When the Sewer-
`Proxy gets a response, it uses the PICS information to mark
`the packets.
`
`16 Claims, 3 Drawing Sheets
`
`43
`
`44
`
`[LIENT—SIDE
`
`
`CLIENT Q PROXY
`
`41
`
`SERVER-SIDE
`PROXY
`
`1+2
`
`SERVER
`
`Petitioner Apple Inc. - Exhibit 1008, p. l
`
`Petitioner Apple Inc. - Exhibit 1008, p. 1
`
`

`

`US. Patent
`
`Jun.6,2000
`
`Sheet170f3
`
`6,073,175
`
`
`
`
`
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`Pefifionerfiqnflelnc.-Exhflflt1008,p.2
`
`Petitioner Apple Inc. - Exhibit 1008, p. 2
`
`

`

`US. Patent
`
`Jun. 6,2000
`
`Sheet 2 0f3
`
`6,073,175
`
`START
`
`GET PICS RATING
`
`LOOK UP POLICY
`FOR RATING
`
`CLASSIFY SESSION
`
`2‘
`
`22
`
`23
`
`2h
`
`NOTIFY NETWORK/SESSION
`0F CLASSIFICATION
`
`END
`
`FIGZ
`
`Petitioner Apple Inc. - Exhibit 1008, p. 3
`
`Petitioner Apple Inc. - Exhibit 1008, p. 3
`
`

`

`US. Patent
`
`Jun.6,2000
`
`Sheet3 0f3
`
`6,073,175
`
`32mm.53%
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`Pefifionerfiqnflelnc.-Exhflflt1008,p.4
`
`Petitioner Apple Inc. - Exhibit 1008, p. 4
`
`
`
`

`

`6,073,175
`
`1
`METHOD FOR SUPPORTING DIFFERENT
`SERVICE LEVELS IN A NETWORK USING
`WEB PAGE CONTENT INFORMATION
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention generally relates to service level
`agreements on a corporate intranet or an internet service
`provider network, and more particularly to methods for
`differentiating service levels.
`2. Background Description
`As corporate networks evolve, they tend to get congested
`as usage exceeds the original points of design. In such an
`environment, it is desirable to give priority or preference to
`traffic that is deemed more relevant to the business of the
`
`corporation than to network traffic which is less relevant to
`the business needs.
`
`The classification of network traffic into different catego-
`ries can be done at various granularities. The granularity of
`classification depends upon the information available to the
`agent system doing the classification. Networks follow a
`layered architecture, and the information available to an
`agent depends on the layer at which the agent operates. An
`agent which is required to operate by looking at the contents
`of individual packets (i.e. operating at layer III of the OSI
`protocol), can only base its classification on the information
`in fields of the packet, such as source/destination machine
`addresses or source/destination port numbers. An agent
`which is not able to combine information across multiple
`packets will only be able to distinguish among traffic belong-
`ing to different sessions, with each session being identified
`by its end-point (host address and port).
`Often times, one would have to carry multiple classes of
`traffic on the same session. This is the case when using a
`product like the IBM WebRedirector. The WebRedirector
`enables a web-client to access multiple applications via a
`single front-end server. The session between the web-client
`and the front-end server carries a variety of traffic. Similarly,
`the reuse of open connections as mandated by the HTTP
`Version 1.1 protocol can lead to the transport of different
`classes of data on the same session between a client and a
`web server.
`
`When business needs can be defined over the granularity
`of one connection, a scheme described in co-pending appli-
`cation for ARCHITECTURE FOR SUPPORTING SER-
`VICE LEVEL AGREEMENTS IN AN IP NETWORK can
`
`there is a problem
`be used for this purpose. However,
`associated with using the connection-level granularity for
`defining business-relevance due to the specific nature of the
`most prevalent method used to access the network, viz.
`through a web browser. Some situations where connection-
`level granularity does not work are:
`A corporation has the same web-server provide different
`types of documents, some which are relevant to business
`needs, and others which are placed there for employee
`entertainment and amusement. Aweb-browser using HTTP
`Version 1.1 is very likely to use the same connection for
`accessing both of these pages.
`in which all
`A corporation is using a web-redirector,
`requests are handled initially by a single server. The server
`then redirects all requests over to the appropriate server.
`Even though each request ends up creating different con-
`nections to the eventual server, there is a single connection
`from the browser to the web-redirector. Even if the browser
`and the web-redirector establish different connections for
`
`2
`their source and destination points are
`each request,
`identical, and it is not possible to prioritize among them.
`It is known in the prior art that web-pages can be rated on
`the basis of their contents using a rating scheme such as
`provided for in PICS (Platform for Internet Content Selec-
`tion; see http://www.w3.org/PICS). PICS provides an infra-
`structure for associating labels with Internet content, thereby
`enabling a marketplace for web page rating services. This
`infrastructure provides “label bureau” sites where ratings of
`web pages (“content label”) can be stored and queried.
`PICS enables the classification of web-page contents into
`categories. It was originally designed to help parents and
`teachers control what children access over the Internet, using
`such categories as “G”, “PG-13” or “NC-17”. However, the
`PICS infrastructure can be used for other purposes. For
`example, a classification scheme can be devised to charac-
`terize web-sites as being relevant to the business to one
`degree or another, as being money-making to one degree or
`another, etc., thereby empowering the operator of an enter-
`prise network to document and imbed in the network
`informed decisions concerning the importance of online
`content.
`
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`However, such a rating needs to be static, since dynamic
`changes to a large number of web-pages is difficult
`to
`administer.
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`At the same time, many enterprise CIOs would like to use
`dynamic policies to access web-sites. A web-site may be
`ranked as being the highest priority during normal business
`hours to support web-based transactions, but may be given
`lower priority after-hours to bulk traffic balancing the enter-
`prise databases.
`SUMMARY OF THE INVENTION
`
`It is therefore an object of the present invention to define
`an architecture for support of service-differentiation in an
`environment where differentiation is to be based on the
`
`contents of the messages, rather than on the source and
`destination points of a connection.
`It
`is a further object of the invention to differentiate
`among service levels provided to the same application, e.g.
`a web browser.
`
`It is also an object of the invention to provide a basis and
`a mechanism for prioritizing between packets having the
`same source and destination points.
`Another object of the invention is to combine a static
`classification scheme (such as PICS) with a dynamic set of
`policy rules to determine the appropriate category of traffic
`at a particular time.
`The present invention builds upon co-pending application
`Ser. No. 09/056,526 for ARCHITECTURE FOR SUPPORT-
`ING SERVICE LEVEL AGREEMENTS IN AN IP
`
`NETWORK, whose disclosure is hereby incorporated by
`reference.
`
`The present invention describes a method that can classify
`the access to different pages made by a web-browser into
`different service-levels on a granularity finer than that of the
`connection. The method is based on the placement of a
`proxy functionality between a web-client and the web-
`server. The proxy intercepts messages between the client and
`the server, and performs the following steps (shown in FIG.
`2):
`determine the static rating (e.g. using the PICS
`infrastructure) of the page being accessed (21);
`translate the static rating into a category (23) by looking
`up policy rules which vary over time (22);
`
`Petitioner Apple Inc. - Exhibit 1008, p. 5
`
`Petitioner Apple Inc. - Exhibit 1008, p. 5
`
`

`

`6,073,175
`
`3
`request the network and/or the web—server to treat the
`session differently according to the category (24).
`The proxy functionality can be placed into a single proxy
`between the server and the client, or two proxies, one on the
`side of the client and other on the side of the server. With a
`single proxy architecture, the requests from the client may
`not receive the desired category of service as they flow from
`the client to the server. This may be acceptable in those cases
`where web-based requests are typically smaller than the
`replies. But in many cases the requests need to be given the
`desired category of service, and this can be achieved by
`using a two proxy architecture.
`The method augments each edge device (edge devices
`being described in the co-pending application for ARCHI-
`TECTURE FOR SUPPORTING SERVICE LEVEL
`
`AGREEMENTS IN AN IP NETWORK) with one or two
`applications, either a Server-Proxy in a single proxy archi-
`tecture or a Client-Proxy and a Server-Proxy in a dual proxy
`architecture. In the dual proxy architecture, the Client-Proxy
`obtains identifying information from the client’s request,
`and then obtains PICS labelling information from a label
`referee. This information is used to obtain a service level
`from an LDAP based SLA directory, and this service level
`information is then imbedded along with a unique identifier
`for the network operator organization in the HTTP header
`request which is transferred to the Server-Proxy. The Server-
`Proxy then strips the header containing the PICS informa-
`tion from the request and forwards the request to the server
`for handling. When the Server-Proxy gets a response,
`it
`translates the PICS rating into a traffic category. This is done
`with policy rules. These policy rules can be configured at the
`proxy, or can be dynamically looked up from a directory
`server which stores policy information. The policy informa-
`tion maps a set of business ratings into a specific category.
`In a preferred implementation of the invention, the con-
`tent of web pages is used in the following manner to
`differentiate priority of access to an internet web server, in
`a network having edge devices which connect the network
`to customer devices. Business ratings of web pages are
`stored at a label bureau node. On receipt of a URL of a
`requested web page, an intermediate node at the web server
`determines its business rating (e.g. by lookup of the URL at
`the label bureau node or at a LDAP directory or the rating
`is found in the header of the web page). Then, at
`the
`intermediate node,
`the business rating is converted to a
`service class by looking up the rating at a directory node. By
`use of the intermediate node, the queuing priority of the web
`page service request is selected according to the service
`class.
`
`In another aspect of the invention, an intermediate node at
`the client side (i.e. browser) looks up the rating (e.g. at a
`label bureau) and sends it to the web-server-side interme-
`diate node, which converts the rating to a service class (e.g.
`by lookup at a directory node) and then uses the service class
`to set a queuing priority for the web page service request.
`In a further aspect of the invention, the two intermediate
`nodes monitor the network traffic between them, and the
`client/browser side intermediate node decides when to acti-
`vate the queuing priority determination mechanism.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The foregoing and other objects, aspects and advantages
`will be better understood from the following detailed
`description of a preferred embodiment of the invention with
`reference to the drawings, in which:
`FIG. 1 is a block diagram of an architecture for support of
`service differentiation in accordance with the invention.
`
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`FIG. 2 is a block diagram of steps taken by a proxy in
`accordance with the invention.
`
`FIG. 3 is a block diagram of elements between client and
`server, showing a single proxy on the server side in accor-
`dance with one implementation of the invention.
`FIG. 4 is a block diagram of elements between client and
`server, showing two proxies in accordance with another
`implementation of the invention.
`DETAILED DESCRIPTION OF A PREFERRED
`EMBODIMENT OF THE INVENTION
`
`Referring now to the drawings, and more particularly to
`FIG. 1, there is shown an architecture in accordance with the
`invention for supporting service-level agreements in the
`context of web-servers.
`
`The edge-device 11 is as per the architecture defined in the
`co-pending application for ARCHITECTURE FOR SUP-
`PORTING SERVICE LEVEL AGREEMENTS IN AN IP
`
`NETWORK. Each edge-device 11 is augmented by two
`applications, which act as a proxy for the applications in the
`subnet behind the edge-device. One of the applications (the
`Client-Proxy) serves as a proxy for the clients in the subnet
`(i.e.
`the clients which initiate the request) and the other
`application (the Server-Proxy) serves as a proxy for the
`server in the subnet (i.e.
`the server which receives the
`request). The two applications would typically listen on
`different ports, but their function can be combined into a
`single process listening on a single port.
`to the
`Browsers in the subnet behind need to point
`Client-Proxy in order to get any class of service better than
`the default or the classes defined on a connection-level
`
`in
`granularity. One can also design a transparent proxy,
`which case the application would pick up the browser
`requests automatically as packets traverse the edge-device,
`without requiring explicit configuration of the browser.
`The Client-Proxy obtains information identifying the cli-
`ent’s source and destination resources from the client’s
`
`request. Examples of such information would be Source IP
`address, Requesting User or group of users, the URL being
`accessed, and the type of applications the source is willing
`to accept.
`The Client-Proxy then queries a PICS Label Referee to
`obtain PICS labeling information. The labeling information
`acts as a front-end to the Lightweight Delivery Access
`Protocol (LDAP) based Service Level Agreements (SLA)
`directory (as defined in the co-pending application ARCHI-
`TECTURE FOR SUPPORTING SERVICE LEVEL
`
`AGREEMENTS IN AN IP NETWORK), which would
`return the right service-level
`to the Client-Proxy. The
`LDAP-based directory will also return the address of the
`Server-Proxy for the specified URL.
`The Client-Proxy would then embed the service-level
`information in the HTTP header request, and transfer it to
`the Server-Proxy. The Server-Proxy strips this extra header
`from the request and forwards it to the server. When the
`Server-Proxy gets the response, it uses the PICS information
`to mark the packets appropriately.
`In order for the Server-Proxy to not get confused with
`multiple PICS-SLA header in the same request, the Client-
`Proxy must embed a unique identifier for the network
`operator organization in addition to the service-level.
`The step of determining the PICS rating can be done in
`one of the following three manners:
`1) On receiving a request for a page, the proxy accesses
`a label-bureau in order to get the ratings for the specific
`page.
`
`Petitioner Apple Inc. - Exhibit 1008, p. 6
`
`Petitioner Apple Inc. - Exhibit 1008, p. 6
`
`

`

`6,073,175
`
`5
`2) On receiving a request for a page, the proxy simply
`forwards the request to the server. The server sends the page
`back to the proxy with the PICS rating included as part of the
`page contents.
`3) On receiving a request for a page, the proxy forwards
`the request to the server. On receiving the response from the
`server, the proxy checks for the presence of the PICS rating
`in the response. If no such rating is found, the proxy contacts
`the label-bureau to obtain the PICS rating.
`The translation of PICS rating into a traffic category is
`done with policy rules. These policy rules can be configured
`at
`the proxy, or can be dynamically looked up from a
`directory server which stores policy information. The policy
`information maps a set of business ratings into a specific
`service level category.
`After determining the category the proxy can do one or
`more of the following functions:
`1) If the request has not been serviced by the server, the
`proxy can include category information as an additional
`argument to the server, either as an extra field in the HTTP
`header or as an additional parameter in the call to the server.
`2) The proxy restricts network access to a limited
`bandwidth, depending on the category of the traffic.
`3) The proxy changes packets belonging to the session, so
`that they are marked with a different Type of Service (TOS)
`byte or are otherwise encoded in a manner which causes the
`network to treat them differently.
`4) The proxy can place packets belonging to the session
`on reserved channels in the network. A reserved channel in
`
`the network can be established using a reservation protocol
`like RSVP, or it can be established using alternate bandwidth
`allocation techniques available in the routers. The proxy can
`change the format of packets belonging to the session so that
`they would belong to a pre-existing reserved channel, or
`may request a new reserved channel for the session. The
`selection of the reserved channel is done on the basis of the
`
`service level category.
`The proxy functionality can be placed at one point
`between the server and the client or at two points between
`the server and the client. It is assumed that the network
`
`between the two proxies is the one on which the differential
`service is desired. In the case of a single proxy, it is placed
`in front of the server.
`
`The successive functions shown in FIG. 2 of determining
`a rating (21) and then determining a service level category
`(22 and 23) can be performed, as described above, at several
`points (Client-Proxy, Server-Proxy, and Server) in process-
`ing packets through the network. It is important to point out
`that later points in processing can perform these functions
`again, thereby overriding determinations made earlier. For
`example, if a Client-Proxy determines both rating and ser-
`vice level category for a request, a Server-Proxy receiving
`the request from the Client-Proxy (or the Server receiving
`the request
`from the Server-Proxy) may downgrade or
`upgrade the service level category based upon information
`about the Client or about traffic history from the Client.
`Turning now to FIG. 3, there is shown a single proxy 31
`on the side of the server 32. A request from the client 34 for
`a particular web page passes through the network 33 and is
`received by the proxy 31. At this point the proxy 31 may
`look up the rating for the requested page from a label-bureau
`and pass the category information to the server to process the
`request. Alternatively, proxy 31 may pass the request to the
`server and, upon receiving the reply, determine the rating
`either by a lookup from the label-bureau or from inspection
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`of the contents of the web page. In either case the proxy 31
`encodes the reply from the server so that it receives differ-
`ential services on the network 33.
`
`It should be noted that with a single proxy architecture as
`shown in FIG. 3, the requests from the client 34 may not
`receive the desired category of service from the network 33.
`In some cases this may be adequate since web-based
`requests are typically smaller than the replies. However, in
`many cases network efficiency will be improved if the
`request is given the same priority as the reply. This can be
`achieved with the two proxy architecture shown in FIG. 4.
`The Client-Proxy 45 receives from the Client 44 a request
`for a particular web page. Then, in accordance with the steps
`shown in FIG. 2, it contacts a label-bureau to obtain the
`PICS rating 21; contacts a directory server to determine the
`policy 22 for mapping the rating label into a category 23;
`and encodes 24 requests from the Client 44 to the Server 42
`so that the Network 43 treats different categories differently.
`The Client-Proxy 45 forwards the request to the Server-
`Proxy 41. The Client-Proxy 45 may optionally include PICS
`rating information and the category information along with
`the request being passed to the Server-Proxy 41. The Server-
`Proxy 41 determines the PICS rating from the request (or
`using one of the schemes mentioned above), and translates
`the rating into its own category. The reply from the Server
`41 is encoded to travel on the Network 43 according to the
`resulting category by looking up applicable rules in an
`LDAP directory.
`While the invention has been described in terms of a
`
`single preferred embodiment, those skilled in the art will
`recognize that the invention can be practiced with modifi-
`cation within the spirit and scope of the appended claims.
`Having thus described our invention, what we claim as
`new and desire to secure by Letters Patent is as follows:
`1. In a network connected to clients by intermediate
`nodes, a method of differentiating priority of access to an
`internet web server based on content of web pages being
`accessed, comprising the steps of:
`storing ratings independent of client input of web pages at
`a node on the network;
`on receipt of a client request for a web page, determining
`at an intermediate node a rating for said web page, said
`determination being made by lookup at said rating
`storage node;
`converting, at said intermediate node, said rating to a
`service class by looking up said rating at an Light-
`weight Delivery Access Protocol (LDAP) directory
`node;
`selecting, for use of said intermediate node, a mechanism
`for providing differentiated services according to said
`service class.
`
`2. The method of claim 1, wherein said rating storage
`node is a label bureau node.
`
`3. The method of claim 1, wherein said rating storage
`node is said server.
`4. The method of claim 1, wherein said selected mecha-
`nism is one or more of:
`
`establishing a queuing priority for said service class;
`setting Type of Service (TOS) flags in package headers;
`using channels in the network which have been desig-
`nated for said service class;
`passing parameters to the server;
`limiting bandwidth used by said service class.
`5. The method of claim 1, wherein a client-side interme-
`diate node determines said rating and sends it to a server-
`
`Petitioner Apple Inc. - Exhibit 1008, p. 7
`
`Petitioner Apple Inc. - Exhibit 1008, p. 7
`
`

`

`6,073,175
`
`7
`side intermediate node, which converts the rating to a
`service class and then uses said service class to select a
`
`mechanism for differentiating services on the network.
`6. The method of claim 5, wherein said client-side and
`said server-side intermediate nodes monitor the network
`traffic between them, and said client-side intermediate node
`decides when to activate said selected mechanism.
`7. The method of claim 1, wherein a client-side interme-
`diate node determines said rating and converts said rating to
`a service class and then uses said service class to select a
`
`mechanism for differentiating services on the network.
`8. The method of claim 7, wherein a server-side interme-
`diate node receives said service class from a client-side
`intermediate node and overrides said service class determi-
`
`nation by converting said rating to another service class and
`then uses said service class to select another mechanism for
`
`differentiating services on the network.
`9. In a network connected to clients by intermediate
`nodes, a system for differentiating priority of access to an
`internet web server based on content of web pages being
`accessed, comprising:
`means for storing ratings independent of client input of
`web pages at a node on the network;
`on receipt of a client request for a web page, means for
`determining at an intermediate node a rating for said
`web page, said determination being made by lookup at
`said rating storage node;
`means for converting, at said intermediate node, said
`rating to a service class by looking up said rating at a
`Lightweight Delivery Access Protocol (LDAP) direc-
`tory node;
`means for selecting, for use of said intermediate node, a
`mechanism for providing differentiated services
`according to said service.
`
`8
`10. The system of claim 9, wherein said rating storage
`node is a label bureau node.
`11. The system of claim 9, wherein said rating storage
`node is said server.
`12. The system of claim 9, wherein said selected mecha-
`nism is one or more of:
`
`means for establishing a queuing priority for said service
`class;
`means for setting Type of Service (TOS) flags in package
`headers;
`means for using channels in the network which have been
`designated for said service class;
`means for passing parameters to the server;
`means for limiting bandwidth used by said service class.
`13. The system of claim 9, wherein a client-side interme-
`diate node determines said rating and sends it to a server-
`side intermediate node, which converts the rating to a
`service class and then uses said service class to select a
`
`mechanism for differentiating services on the network.
`14. The system of claim 13, wherein said client-side and
`said server-side intermediate nodes monitor the network
`traffic between them, and said client-side intermediate node
`decides when to activate said selected mechanism.
`
`5
`
`10
`
`15
`
`20
`
`15. The system of claim 9, wherein a client-side interme-
`25 diate node determines said rating and converts said rating to
`a service class and then uses said service class to select a
`
`mechanism for differentiating services on the network.
`16. The system of claim 15, wherein a server-side inter-
`mediate node receives said service class from a client-side
`
`30 intermediate node and overrides said service class determi-
`nation by converting said rating to another service class and
`then uses said service class to select another mechanism for
`
`differentiating services on the network.
`
`Petitioner Apple Inc. - Exhibit 1008, p. 8
`
`Petitioner Apple Inc. - Exhibit 1008, p. 8
`
`