|Publication number||USRE41811 E1|
|Application number||US 10/679,203|
|Publication date||Oct 5, 2010|
|Filing date||Oct 2, 2003|
|Priority date||Jan 4, 1999|
|Also published as||US6298383|
|Publication number||10679203, 679203, US RE41811 E1, US RE41811E1, US-E1-RE41811, USRE41811 E1, USRE41811E1|
|Inventors||Andrew Mark Gutman, Aravind Sitaraman, Sampath Kumar Sthothra Bhasham, Kalpathi S. Suryanarayanan|
|Original Assignee||Cisco Technology, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (45), Non-Patent Citations (16), Referenced by (10), Classifications (7), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1. Field of the Invention
The present invention relates to the field of data communications networks. More particularly, this invention relates to a method and apparatus for unifying the operation of authentication, authorization and accounting services and proxy services in a data communications network.
2. The Background
ISPs (Internet Service Providers) and Telcos (telephone companies) typically offer wholesale internet access and retail internet access to their subscribers. Wholesale access is typically offered to subsidiary and specialized service providers, CLECs (Competitive Local Exchange Carriers), corporations, and Community of Interest (COI) providers. Naturally, the processing afforded customers of the wholesale variety differs from the processing afforded customers of the retail variety. Subscriber information for individual wholesale users is usually stored by those who lease data communications network access from the ISP or Telco. Hence, corporations, CLECs and COI providers do not normally share their user information with the wholesale providers. The ISP or Telco, however, typically also has its own retail subscribers whose user information is stored in its databases. Hence, the ISP or Telco must identify an incoming user as a wholesale user or a retail user and initiate different actions for an incoming user based upon this status.
See, for example,
Traditional wholesale ISPs and Roaming Service Providers offer network access through a technique called “Authentication proxying.” Proxying involves the transfer of the Authentication responsibility to the “owner” of the subscriber. Thus, if a corporation was to outsource its corporate intranet to an ISP, what it gives up is the maintenance of its dial-up servers (i.e., the NASes). It does not, however, normally want to give up the control or information of its employees. Hence, when a corporate user dials in to such an ISP's network access servers, the user essentially perceives that the user is dialing into a corporate facility when the user is actually dialing into the ISP's domain and then somehow gaining admittance to the corporation's intranet.
What really happens in that scenario is that the ISP determines that the user belongs to Corporation A(CorpA) by parsing either the fully qualified domain name (FQDN) supplied by the user, a DNIS ID, or some other mechanism. Having determined that the user trying to gain access belongs to CorpA, the ISP cannot really authenticate the user. As noted earlier, the user's record is still with the corporation. Hence, the ISP will “proxy” out the authentication transaction to the corporation. An AAA service within the corporation then identifies the user, verifies the password, and provisions the user. Then the AAA service notifies the ISP's proxy server that the user is acceptable and passes along provisioning details associated with the user (such as an IP address to use or a pool identification of an IP address pool from which an IP address needs to be allocated). The ISP then grants the user access to the network based upon the reply it gets back from the corporation. This technique is called “proxying.” This is shown in FIG. 2.
To be able to do this, the ISP maintains minimal information on its proxy server 14 at its PoP. Information such as supported domain names, the IP address to which the transaction is to be sent, the port number to which the transaction is to be addressed, etc. are stored (see FIG. 3).
For example, turning now to
When the subscriber is granted access, or leaves the network, the accounting transactions will now have to be shared with the wholesale customers of the ISP/Telco. That is, the ISP/Telco will keep a record with which to bill or otherwise account to CorPA for services rendered and the record will also need to be sent to CorpA's AAA. Typically, the wholesale provider (e.g., the ISP) will use a roaming service product such as the Global Roaming Server™ (GRS), a product of Cisco Systems, Inc. of San Jose, Calif., to achieve this objective. In the retail case, the ISP/Telco will use a product like Cisco Secure™, a product of Cisco Systems, Inc., to act as an authentication, authorization and accounting (AAA) service to authenticate and authorize the user. This approach, however, poses some problems for the ISP/Telco.
The ISP/Telco needs to maintain two different sets of NASes as diagrammed in
Accordingly, it would be desirable to provide a capability for allowing ISPs and Telcos to seamlessly offer wholesale and retail data communications network access, unify the disparate systems that specialize in these access control segments and scale both systems to simultaneously reside on a plurality of PoPs while behaving in a distributed manner within the data communications network.
A single database maintained centrally hosts both proxy service data and authentication, authorization and accounting (AAA) data. Data is then copied to storage used locally by each system when both systems are instantiated. Therefore the ISP/Telco need not maintain two different data bases. A protocol gateway (PGW) is used to determine if the incoming user is a wholesale or retail user. The PGW filters the domain portion of the access request to locate a remote AAA service. If one such service is found, the PGW routes the communication via the GRS to proxy it to the remote AAA service. The returned packet from the remote AAA service is then searched for an IP address to be assigned to the incoming user. If one is not found the PGW obtains a dynamically allocated IP address from a DHCP server (using an IP-Pool-ID if supplied in the returned packet from the remote AAA service). The same mechanism is used to forward accounting event packets from the NAS to the remote AAA service. The PGW may monitor more than one proxy service and/or AAA service and load balance among them.
Those of ordinary skill in the art will realize that the following description of the present invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons after a perusal of the within disclosure.
In accordance with a presently preferred embodiment of the present invention, the components, processes and/or data structures are implemented using a gateway device and other services implemented using C++ programs running on an Enterprise 2000™ server running Sun Solaris™ as its operating system. The Enterprise 2000™ server and Sun Solaris™ operating system are products available from Sun Microsystems, Inc. of Mountain View, Calif. Different implementations may be used and may include other types of operating systems, computing platforms, computer programs, firmware and/or general purpose machines. In addition, those of ordinary skill in the art will readily recognize that devices of a less general purpose nature, such as hardwired devices, devices relying on FPGA (field programmable gate array) or ASIC (Application Specific Integrated Circuit) technology, or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein.
The protocol gateway (PGW or gateway) is a device which couples the user via a network access server (NAS) to the data communications network. The term gateway is not meant to be limited to a single type of device, as any device, hardware or software, that may act as a bridge between the user and the network may be considered a gateway for the purposes of this application. In accordance with a presently preferred embodiment of the present invention, the PGW is a software service operating on a general purpose computer running the User Control Point (UCP) software package available from Cisco Systems, Inc. of San Jose, Calif.
The authentication, authorization and accounting (AAA) service performs user authentication, user authorization and user accounting functions. It may be a Cisco ACS™ product such as Cisco Secure™, available from Cisco Systems, Inc. of San Jose, Calif., or an equivalent product. In accordance with a presently preferred embodiment of the present invention, the Remote Authentication Dial-In User Service (RADIUS) protocol is used as the communication protocol between the gateway and the AAA and GRS proxy services. RADIUS is an Internet standard track protocol for carrying authentication, authorization, accounting and configuration information between devices that desire to authenticate their links and a shared AAA or GRS service. Those of ordinary skill in the art will now realize that systems, methods and apparatuses may employ other Internet protocols such as TACACS+ can be used as acceptable authentication communications links between the various communications devices that encompass the data communications network and still be within the inventive concepts disclosed herein. The global roaming service (GRS) is also a an AAA service which is capable of proxying transactions to remote AAA service services. It also preferably uses the RADIUS protocol or an equivalent.
One way in which the present invention may come into use involves the concept of roaming users. A roaming user is, for example, a traveling person with a lap top. If the person wants to reach a corporate intranet or local ISP, he or she can (1) dial the number of the home PoP (point of presence) and incur potentially large telephone bills; (2) dial a “toll free” number such as an 800 number which can also be expensive—to the provider; or (3) use a global roaming server model. In the global roaming server model, ISPs with PoPs in different locations make cross-agreements with one another so as to provide local telephone access numbers to ISPs without any other (or a sufficient) presence in a location. To the user, it appears that his ISP has PoPs everywhere that there is a roaming agreement in place with a cooperating ISP.
A global roaming service (“GRS”) at a PoP can parse the fully qualified domain name (“FQDN”) of the user (e.g., joe@ISPA.NET) and determine that Joe belongs to ISPA.NET. The GRS can then send an authentication request to ISPA-NET's AAA server to authenticate and authorize Joe in a conventional manner. Accounting event information, e.g., accounting start packets associated with log-in and accounting stop packets associated with log-out, are sent both to the GRS at the local PoP and to ISPA.NET's AAA server to enable the local PoP to account for use by Joe at the local PoP and so bill ISPA.NET, if desired, and to allow ISPA.NET to bill Joe, if desired. It also provides a mechanism for tracking this type of usage which can serve a number of purposes.
GRSes have their own associated databases which keep lists of remote AAAs, their IP addresses, their port numbers and their associated domain names.
To render the roaming model more tenable to the myriad IPSs and Telcos which might see fit to enter into these cross-agreements and thus make roaming easier for the end users, the process must be simplified and made scaleable. Under the prior model, as shown in
The database 18 and access database adapter 20 can run on the same host 14 as the NCC 12, as depicted in
The information bus 22 that serves as the transportation medium for the presently preferred embodiment of the present invention can be Common Object Request Broker Architecture (CORBA)-based. The CORBA-based information bus is capable of handling the communication of events to and from objects in a distributed, multi-platform environment. The concept of a CORBA-based information bus is well known by those of ordinary skill in the art. Other acceptable communication languages can be used as are also known by those of ordinary skill in the art.
CORBA provides a standard way of executing program modules in a distributed environment. A broker 24, therefore, may be incorporated into an Object Request Broker (ORB) within a CORBA compliant network. To make a request of an ORB, a client may use a dynamic invocation interface (which is a standard interface which is independent of the target object's interface) or an Object Management Group Interface Definition Language (OMG IDL) stub (the specific stub depending on the interface of the target object). For some functions, the client may also directly interact with the ORB. The object is then invoked. When an invocation occurs, the ORB core arranges so a call is made to the appropriate method of the implementation. A parameter to that method specifics the object being invoked, which the method can use to locate the data for the object. When the method is complete, it returns, causing output parameters or exception results to be transmitted back to the client.
In accordance with a presently preferred embodiment of the present invention an Enterprise Application Integration (EAT) system is used to broker the flow of information between the various services and adapters comprising the data network management system of the present invention. An example of an EAI system that can be incorporated in the presently preferred invention is the ActiveWorks Integration System, available from Active Software of Santa Clara, Calif. As shown in
Referring back to
By way of example, the node 34 of
The protocol gateway service 30a is used to couple the network user to the data communication network. The protocol gateway service 30a functions as an interface to the NASes that allows access requests received from a user to be serviced using components that may communicate using different protocols. A typical protocol gateway service 30a may be able to support different user access methodologies, such as dial-up, frame relay, leased lines, ATM (Asynchronous Transfer Mode), ADSL (Asymmetric Digital Subscriber Line) and the like. Used in conjunction with the protocol gateway service 30a, the AAA service 30c performs user authentication, authorization and accounting functions. The AAA service 30c stores user profile information and tracks user usage. The profile information stored in the AAA service 30c is proxied to the protocol gateway service 30a when a network user desires network access.
The DNS service 30e is used to return Internet protocol (IP) addresses in response to domain names received, for example, from a protocol gateway service 30a. For example, if the DNS service 30e receives a domain name query from the protocol gateway service 30a, it has the capability to locate the associated numerical IP address from within the memory of the DNS service (or another DNS service) and return this numerical IP address to the protocol gateway service 30a.
The DHCP service 30d is used as a dynamic way of assigning IP addresses to the network users as well known to those of ordinary skill in the art.
Each of these services 30a, 30b, 30c, 30d, 30e is in communication with a corresponding service adapter 28a, 28b, 28c, 28d, 28e. The service adapter subscribes to and publishes various events on the information bus 22. The service adapter is configured so that it subscribes to events published by the access database adapter 20 of the NCC 12. The service adapter also publishes events to the access database adapter 20 of the NCC 12.
The following is an exemplary listing and definition of some of the events published by and subscribed to by the access database adapter and the service adapters which are pertinent to this invention. This listing is by way of example and is not intended to be exhaustive or limiting in any way. Other events are possible and can be used in this invention without departing from the inventive concepts herein disclosed.
The NCC 12 publishes “configure” events to the service adapters 28a, 28b, 28c, 28d, 28e. Configure events are published to configure the service adapters upon initial start up of the service adapters or to modify a preexisting configuration. A configure event can be delivered to a service adapter directly from the access database adapter 20 at the NCC 12. The service adapters update their corresponding configuration files upon receiving a configure event. An example of the information contained within a configure event includes the GUID (global unique identifier) of the publisher, the GUID of the subscriber, listening port configuration, sink port configuration, protocol handler information, engine data and facility data.
The NCC 12 publishes “start” events that are subscribed to by a control adapter such as control adapter 29 associated with a host computer at a node to cause the control adapter to start up one or more specific services. Since the control adapter is always responsible for starting a service, the start events are always subscribed to by the control adapters as opposed to the service adapters. An example of the information contained within a start event includes the GUID of the publisher, the GUID of the subscribing control adapter, the GUID of the service to be started, the service name and the absolute path where the service binary resides. The access database adapter 20 of the NCC 12 also publishes “stop” events that are subscribed to by the control adapter to cause the control adapter to shut down a specific service or multiple services. Since the control adapter is always responsible for stopping a service, the stop events are always subscribed to by the control adapter as opposed to the service adapters. Once the control adapter receives the stop event, it publishes a stop event to the service adapter of the corresponding service. The control adapter allows the service sufficient time to shut down. If the service does not respond to the stop event and continues running, the control adapter can explicitly kill the service based on the process ID found in the configuration file. An example of information contained within a start event includes the GUID of the publisher, the GUID of the subscribing control adapter, the GUID of the service to be stopped and the name of the service to be stopped.
Other events may be published and subscribed to.
The configure event is used to publish the current contents of a master database relevant to GRS and AAA services at the various nodes of the data communications network. Thus the master database may be maintained and serviced at the NOC or some other convenient facility and the AAA services and GRS services updated with information automatically without the need to manually update their separate databases.
The PGW is used as a protocol gateway between the NASes and the AAA and GRS services. The PGW parses the FQDN of incoming users and sends access requests from local users to the local AAA and access requests for roaming users to the GRS. The GRS, in turn, forwards the access requests to the remote AAA belonging to the user's provider in accordance with the conventional proxy model.
The PGW has the ability to load balance by monitoring the condition and response times of its respective GRS services and AAA services. Thus, if one such services is particularly loaded, incoming calls may be directed to other services. If one such server has crashed or becomes non responsive, it may be bypassed. In the present configurations where NASes are directly connected to a GRS and or an AAA service, a dead service can result in the NASes connected to the dead service becoming non-responsive. This condition is avoided by using the PGW as a front end to the GRS and AAA service.
In accordance with the present invention IP addresses may be assigned to incoming users in a number of ways. For users having permanently or otherwise allocated IP addresses reflected in their user service profiles in their respective AAA services, they will receive that address. This is done by returning the IP address in the access-accept packet ultimately returned to the NAS via the PGW.
For users of the local ISP who do not have pre-allocated IP addresses, a DHCP (dynamic host control protocol) service such as one running in a host at the PoP will provide a DHCP IP address from a pool of such addresses assigned to the ISP.
For wholesale users, an IP address may be returned from a DHCP service running remotely at their provider, it may be assigned by the ISP as if the user were a retail user of the ISP, or a separate pool of IP addresses maintained locally at the ISP on behalf of the provider can be identified by the access-accept packet and an address selected therefrom by the local DHCP service.
Turning now to
At reference numeral 128 the protocol gateway load balances by distributing network access requests among the relevant services in a manner designed to more or less equally share the load. Any convenient mechanism may be used, such as a round-robin schedule or another conventional scheduling algorithm.
At reference numeral 130 the protocol gateway detects non-responsive services and bypasses them. An error condition event may also be published to allow other components of the data communications network to become aware of the failure.
Turning finally to
While embodiments and applications of the invention have been shown and described, it would be apparent to those of ordinary skill in the art, after a perusal of the within disclosure, that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4763191||Mar 17, 1986||Aug 9, 1988||American Telephone And Telegraph Company, At&T Bell Laboratories||Dial-up telephone network equipment for requesting an identified selection|
|US4922486||Mar 31, 1988||May 1, 1990||American Telephone And Telegraph Company||User to network interface protocol for packet communications networks|
|US4962497||Sep 21, 1989||Oct 9, 1990||At&T Bell Laboratories||Building-block architecture of a multi-node circuit-and packet-switching system|
|US5003595||Aug 29, 1989||Mar 26, 1991||At&T Bell Laboratories||Secure dial access to computer systems|
|US5241594||Jun 2, 1992||Aug 31, 1993||Hughes Aircraft Company||One-time logon means and methods for distributed computing systems|
|US5241599||Oct 2, 1991||Aug 31, 1993||At&T Bell Laboratories||Cryptographic protocol for secure communications|
|US5351136||Jul 10, 1992||Sep 27, 1994||Industrial Technology Research Institute||Facsimile apparatus and method for sending and receiving private information|
|US5416842||Jun 10, 1994||May 16, 1995||Sun Microsystems, Inc.||Method and apparatus for key-management scheme for use with internet protocols at site firewalls|
|US5423002||Feb 28, 1994||Jun 6, 1995||3Com Corporation||System for extending network resources to remote networks|
|US5440635||Aug 23, 1993||Aug 8, 1995||At&T Corp.||Cryptographic protocol for remote authentication|
|US5560005||Feb 25, 1994||Sep 24, 1996||Actamed Corp.||Methods and systems for object-based relational distributed databases|
|US5621721||Jan 12, 1995||Apr 15, 1997||Stratacom, Inc.||Maintaining database integrity throughout a communication network|
|US5655077||Dec 13, 1994||Aug 5, 1997||Microsoft Corporation||Method and system for authenticating access to heterogeneous computing services|
|US5668857||Mar 29, 1996||Sep 16, 1997||Netspeed, Inc.||Communication server apparatus and method|
|US5671354||Feb 23, 1996||Sep 23, 1997||Hitachi, Ltd.||Method of assisting server access by use of user authentication information held in one of servers and a method of assisting management user account for use of servers|
|US5684950||Sep 23, 1996||Nov 4, 1997||Lockheed Martin Corporation||Method and system for authenticating users to multiple computer servers via a single sign-on|
|US5717604||May 25, 1995||Feb 10, 1998||Wiggins; Christopher||Network monitoring system for tracking, billing and recovering licenses|
|US5745556||Sep 22, 1995||Apr 28, 1998||At&T Corp.||Interactive and information data services telephone billing system|
|US5768521||Feb 2, 1996||Jun 16, 1998||Intel Corporation||General purpose metering mechanism for distribution of electronic information|
|US5778182||Nov 7, 1995||Jul 7, 1998||At&T Corp.||Usage management system|
|US5809422||Mar 8, 1996||Sep 15, 1998||Watkins Johnson Company||Distributed microcellular communications system|
|US5815665||Apr 3, 1996||Sep 29, 1998||Microsoft Corporation||System and method for providing trusted brokering services over a distributed network|
|US5835727||Dec 9, 1996||Nov 10, 1998||Sun Microsystems, Inc.||Method and apparatus for controlling access to services within a computer network|
|US5838683||Mar 13, 1995||Nov 17, 1998||Selsius Systems Inc.||Distributed interactive multimedia system architecture|
|US5845070||Dec 18, 1996||Dec 1, 1998||Auric Web Systems, Inc.||Security system for internet provider transaction|
|US5898780||Oct 9, 1996||Apr 27, 1999||Gric Communications, Inc.||Method and apparatus for authorizing remote internet access|
|US5905736||Apr 22, 1996||May 18, 1999||At&T Corp||Method for the billing of transactions over the internet|
|US5933625||Aug 30, 1996||Aug 3, 1999||Akira Sugiyama||Unique time generating device and authenticating device using the same|
|US5944824||Apr 30, 1997||Aug 31, 1999||Mci Communications Corporation||System and method for single sign-on to a plurality of network elements|
|US5960409||Oct 11, 1996||Sep 28, 1999||Wexler; Daniel D.||Third-party on-line accounting system and method therefor|
|US5970477||Jul 15, 1996||Oct 19, 1999||Bellsouth Intellectual Property Management Corporation||Method and system for allocating costs in a distributed computing network|
|US5991810||Aug 1, 1997||Nov 23, 1999||Novell, Inc.||User name authentication for gateway clients accessing a proxy cache server|
|US6011910||Apr 8, 1997||Jan 4, 2000||3Com Corporation||Supporting authentication across multiple network access servers|
|US6018619||May 24, 1996||Jan 25, 2000||Microsoft Corporation||Method, system and apparatus for client-side usage tracking of information server systems|
|US6021496||Jul 7, 1997||Feb 1, 2000||International Business Machines Corporation||User authentication from non-native server domains in a computer network|
|US6026440||Jan 27, 1997||Feb 15, 2000||International Business Machines Corporation||Web server account manager plug-in for monitoring resources|
|US6035281||Jun 16, 1997||Mar 7, 2000||International Business Machines Corporation||System and method of multiparty billing for Web access|
|US6047376||Mar 19, 1997||Apr 4, 2000||Toshiba Information Systems (Japan) Corporation||Client-server system, server access authentication method, memory medium stores server-access authentication programs, and issuance device which issues the memory medium contents|
|US6052730||Jan 9, 1998||Apr 18, 2000||The Board Of Trustees Of The Leland Stanford Junior University||Method for monitoring and/or modifying web browsing sessions|
|US6092196||Nov 25, 1997||Jul 18, 2000||Nortel Networks Limited||HTTP distributed remote user authentication system|
|US6119160||Oct 13, 1998||Sep 12, 2000||Cisco Technology, Inc.||Multiple-level internet protocol accounting|
|US6141687||May 8, 1998||Oct 31, 2000||Cisco Technology, Inc.||Using an authentication server to obtain dial-out information on a network|
|US6263369 *||Oct 30, 1998||Jul 17, 2001||Cisco Technology, Inc.||Distributed architecture allowing local user authentication and authorization|
|EP0567217A2||Mar 12, 1993||Oct 27, 1993||3Com Corporation||System of extending network resources to remote networks|
|WO1999053408A1||Apr 14, 1999||Oct 21, 1999||Juno Online Services, Inc.||Method and apparatus to control a client in a communications network|
|1||Active Software, Inc., "Active Software's Integration Systems", printed from http://www.activesw.com/products/products.html, on Jul. 24, 1998, pp. 1-6.|
|2||Active Software, Inc., "Active Software's Integration Systems", printed from http://www.activesw.com/products/products.html, on Jul. 24, 1998.|
|3||Ascend Communications, Inc., "Access Control Product Information", 4 pages, 1997.|
|4||Ascend Communications, Inc., "Access Control Product Information", 4 pages, undated.|
|5||Ascend Communications, Inc., "Multi VPN from Ascend Communications: Breaking Down the Barriers to VPNs", White Paper, 1998.|
|6||Ascend Communications, Inc., "MultiVPN from Ascend Communications: Breaking Down the Barriers to VPNs," White Paper, 1998.|
|7||Ascend Communications, Inc., "Remote Access Network Security", printed from http://www.ascend.com/1103.html, on Jul. 24, 1998, pp. 1-8.|
|8||Bellovin, Steven M., "Problem Areas for the IP Security Protocols", Jul. 22-25, 1996, Proceedings of teh Sixth Usenix UNIX Security Symposium, San Jose, CA.|
|9||Bracho, Dr. Rafael, "Integrating the Corporate Computing Environment with Active Software," Nov. 18, 1998, Active Software, pp. 1-17.|
|10||Bracho, Dr. Rafael, "Mastering Corporate Computing with the ActiveWeb System," 1996, Active Software, Inc.|
|11||Dr. Rafael Bracho, "Integrating the Corporate Computing Environment with Active Software", Nov. 18, 1998, pp. 1-17.|
|12||Dr. Rafael Bracho, "Mastering Corporate Computing with the ActiveWeb(TM) System", Aug. 2, 1996.|
|13||Dr. Rafael Bracho, "Mastering Corporate Computing with the ActiveWeb™ System", Aug. 2, 1996.|
|14||IBM, "IBM Introduces new Subscriber Management System for Internet Service Providers," Dec. 2, 1998, IBM News, p. 1.|
|15||Rigney et al., "Remote Authentication Dial in User Service (RADIUS)," Network Working Group, RFC 2138, Apr. 1997, pp. 1-57.|
|16||Steven M Bellovin, "Problem Areas for the IP Security Protocols", Proceedings of the Sixth Usenix UNIX Security Symposium, Jul. 22-25, 1996, San Jose, CA.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US8272039 *||May 2, 2008||Sep 18, 2012||International Business Machines Corporation||Pass-through hijack avoidance technique for cascaded authentication|
|US8472966 *||Dec 30, 2005||Jun 25, 2013||Telecom Italia S.P.A.||Method of operating a wireless communications network, and wireless communications network implementing the method|
|US8588240||Oct 7, 2009||Nov 19, 2013||Cisco Technology, Inc.||Methods and systems for accounting in an access gateway|
|US8819191||Jul 12, 2011||Aug 26, 2014||Cisco Technology, Inc.||Efficient use of dynamic host configuration protocol in low power and lossy networks|
|US9325676||May 24, 2012||Apr 26, 2016||Ip Ghoster, Inc.||Systems and methods for protecting communications between nodes|
|US9348927||May 7, 2012||May 24, 2016||Smart Security Systems Llc||Systems and methods for detecting, identifying and categorizing intermediate nodes|
|US9515874||Jul 16, 2014||Dec 6, 2016||Cisco Technology, Inc.||Efficient use of dynamic host configuration protocol in low power and lossy networks|
|US20090075669 *||Dec 30, 2005||Mar 19, 2009||Daniele Franceschini||Method of operating a wireless communications network, and wireless communications network implementing the method|
|US20090276838 *||May 2, 2008||Nov 5, 2009||International Business Machines Corporation||Pass-through hijack avoidance technique for cascaded authentication|
|US20100085978 *||Oct 7, 2009||Apr 8, 2010||Rajesh Ramankutty||Methods and systems for accounting in an access gateway|
|International Classification||H04L29/06, G06F13/00|
|Cooperative Classification||H04L63/0892, H04L63/0281|
|European Classification||H04L63/02D, H04L63/08|