Abstract:
Embodiments provide techniques for mobile route optimization authentication protocols. Embodiments allow for system control over whether route optimization is allowed or not allowed. A conditional allowance of route optimization solves several billing and security issues by allowing the system to impose appropriate charges for the route optimization feature or prevent route optimization where message flow using care-of addressing can be monitored.

Description:
PRIORITY 
       [0001]    This application is a continuation of and claims priority to U.S. patent application Ser. No. 13/385,643, filed on Feb. 28, 2012, which in turn is a continuation of U.S. Pat. No. 8,171,120, filed on Nov. 21, 2007, and which all claim priority to U.S. Provisional Patent Application Ser. No. 60/866,891 filed on Nov. 22, 2006, the disclosures of which are incorporated in their entirety by reference herein. 
     
    
     BACKGROUND 
       [0002]    Present-day Internet communications represent the synthesis of technical developments begun in the 1960s. During that time period, the Defense Department developed a communication system to support communication between different United States military computer networks, and later a similar system was used to support communication between different research computer networks at United States universities. 
       The Internet 
       [0003]    The Internet, like so many other high tech developments, grew from research originally performed by the United States Department of Defense. In the 1960s, Defense Department officials wanted to connect different types of military computer networks. These different computer networks could not communicate with each other because they used different types of operating systems or networking protocols. 
         [0004]    While the Defense Department officials wanted a system that would permit communication between these different computer networks, they realized that a centralized interface system would be vulnerable to missile attack and sabotage. To avoid this vulnerability, the Defense Department required that the interface system be decentralized with no vulnerable failure points. 
         [0005]    The Defense Department developed an interface protocol for communication between these different network computers. A few years later, the National Science Foundation (NSF) wanted to connect different types of network computers located at research institutions across the country. The NSF adopted the Defense Department&#39;s interface protocol for communication between the research computer networks. Ultimately, this combination of research computer networks would form the foundation of today&#39;s Internet. 
       Internet Protocols 
       [0006]    The Defense Department&#39;s interface protocol was called the Internet Protocol (IP) standard. The IP standard now supports communication between computers and networks on the Internet. The IP standard identifies the types of services to be provided to users and specifies the mechanisms needed to support these services. The IP standard also describes the upper and lower system interfaces, defines the services to be provided on these interfaces, and outlines the execution environment for services needed in this system. 
         [0007]    A transmission protocol, called the Transmission Control Protocol (TCP), was developed to provide connection-oriented, end-to-end data transmission between packet-switched computer networks. The combination of TCP with IP (TCP/IP) forms a system or suite of protocols for data transfer and communication between computers on the Internet. The TCP/IP standard has become mandatory for use in all packet switching networks that connect or have the potential for utilizing connectivity across network or sub-network boundaries. 
         [0008]    A computer operating on a network is assigned a unique physical address under the TCP/IP protocols. This is called an IP address. The IP address can include: (1) a network ID and number identifying a network, (2) a sub-network ID number identifying a substructure on the network, and (3) a host ID number identifying a particular computer on the sub-network. A header data field in the information packet will include source and destination addresses. The IP addressing scheme imposes a sensible addressing scheme that reflects the internal organization of the network or sub-network All information packets transmitted over the Internet will have a set of IP header fields containing this IP address. 
         [0009]    A router is located on a network and is used to regulate the transmission of information packets into and out of computer networks and within sub-networks. Routers are referred to by a number of names including Home Agent, Home Mobility Manager, Home Location Register, Foreign Agent, Serving Mobility Manager, Visited Location Register, and Visiting Serving Entity. A router interprets the logical address of an information packet and directs the information packet to its intended destination. Information packets addressed between computers on the subnetwork do not pass through the router to the greater network, and as such, these sub-network information packets will not clutter the transmission lines of the greater network. If an information packet is addressed to a computer outside the sub-network, the router forwards the packet onto the greater network. 
         [0010]    The TCP/IP network includes protocols that define how routers will determine the transmittal path for data through the network. Routing decisions are based upon information in the IP header and entries maintained in a routing table. A routing table possesses information for a router to determine whether to accept the communicated information packet on behalf of a destination computer or pass the information packet onto another router in the network or subnetwork. The routing table&#39;s address data enables the router to accurately forward the information packets. 
         [0011]    The routing table can be configured manually with routing table entries or with a dynamic routing protocol. In a dynamic routing protocol, routers update routing information with periodic information packet transmissions to other routers on the network. This is referred to as advertising. The dynamic routing protocol accommodates changing network topologies, such as the network architecture, network structure, layout of routers, and interconnection between hosts and routers. Internet Control Message Protocol (ICMP) information packets are used to update routing tables with this changing system topology. 
       The IP-Based Mobility System 
       [0012]    The Internet protocols were originally developed with an assumption that Internet users would be connected to a single, fixed network. With the advent of portable computers and cellular wireless communication systems, the movement of Internet users within a network and across network boundaries has become common. Because of this highly mobile Internet usage, the implicit design assumption of the Internet protocols has been violated. 
         [0013]    In an IP-based mobile communication system, the mobile communication device (e.g. cellular phone, pager, computer, etc.) is called a mobile node. Typically, a mobile node changes its point of attachment to a foreign network while maintaining connectivity to its home network. A mobile node may also change its point of attachment between sub-networks in its home network or foreign network. The mobile node will always be associated with its home network and sub-network for IP addressing purposes and will have information routed to it by routers located on the home and foreign network. Generally, there is also usually a correspondence node, which may be mobile or fixed, communicating with the mobile node. 
       IP Mobility Protocols 
       [0014]    During the formative years since the Internet was first established, Internet Protocol version 4 (1Pv4) was recognized and adopted as the standard version of the Internet Protocol. With the advent of mobile IP and proliferation of computers and computer systems linked to the Internet, various limitations in the 1Pv4 standard and associated procedures have developed and emerged. In response, new standards are evolving and emerging. 
         [0015]    The most pressing limitation in the 1Pv4 standard is the restriction on the number of possible IP addresses imposed by the 32-bit address field size. A newer standard, the Internet Protocol version 6 (IPV 6), increases the size of the available address space 400% to 128 bits, which vastly increases the number of available addresses. While the 32-bit address field provides 2 32  or approximately 4 billion IP address possibilities, a 128-bit field provides 2 128  (340×10 12 ) IP address possibilities. 
         [0016]    A number of benefits emerge from this vastly larger available address field. First, there is little chance of exhausting the number of IP addresses. Second, a large address field allows aggregation of many network-prefix routers into a single network-prefix router. Finally, the large address pool allows nodes to auto configure using simple mechanisms. One practical advantage as a result is elimination of designated foreign agents to route information packets to a visiting mobile node on a foreign network. 
       IP Mobility Care-of Addressing 
       [0017]    In a mobile IP network, nodes will transmit notification and discovery information packets onto the network to advertise their presence on the network and solicit advertisements from other nodes. While on a foreign network, a mobile node will be assigned a care-of address that will be used to route information packets to the foreign network and the attached mobile node. An advertisement from a router on the foreign network will inform a mobile node that is attached to a foreign network. The mobile node will typically create a care-of address on the foreign network, which it will transmit to its home network in an information packet to register the care-of address. Information packets addressed to the mobile node on the home network have the care-of address added. This information packet containing the care-of address will then be forwarded and routed to the mobile node on the foreign network by a router on the foreign network according to the care-of address. 
       Authentication, Authorization and Accounting (“AAA”) 
       [0018]    In an IP-based mobile communications system, the mobile node changes its point of attachment to the network while maintaining network connectivity. When a mobile node travels outside its home administrative domain, however, the mobile node must communicate through multiple domains in order to maintain network connectivity with its home network. While connected to a foreign network controlled by another administrative domain, network servers must authenticate, authorize and collect accounting information for services rendered to the mobile node. This authentication, authorization, and accounting activity is called “AAA”, and AAA servers on the home and foreign network perform the AAA activities for each network. 
         [0019]    Authentication is the process of proving one&#39;s claimed identity, and security systems on a mobile IP network will often require authentication of the system user&#39;s identity before authorizing a requested activity. The AAA server authenticates the identity of an authorized user and authorizes the mobile node&#39;s requested activity. Additionally, the AAA server will also provide the accounting function including tracking usage and charges for use of transmissions links between administrative domains. 
         [0020]    Another function for the AAA server is to support secured transmission of information packets by storing and allocating security associations. Security associations refer to those encryption protocols, nonces, and keys required to specify and support encrypting an information packet transmission between two nodes in a secure format. The security associations are a collection of security contexts existing between the nodes that can be applied to the information packets exchanged between them. Each context indicates an authentication algorithm and mode, a shared or secret key or appropriate public/private key pair, and a style of replay protection. 
       Route Optimization 
       [0021]    Route optimization allows the Mobile Node (MN) to establish a direct link a correspondent node instead of using a care-of address forwarding and encapsulation operation. Route optimization, as its name implies, optimizes the routing efficiency to a Mobile Node, and IPv6 protocol automatically establishes route optimization by default. Because the default procedures in IPv6 protocol, there is a lack of control over the selection and authorization of route optimization feature in the Mobile IPv6 protocol. In the prior art, there is no mechanism to control the route optimization feature. There is a need to control the route optimization feature to control billing options for subscriber charges. Moreover, there is also a security reason to prevent route optimization and force the user to forward transmissions through the home network for monitoring purposes, instead of permitting a direct link between the correspondent node and the mobile node (MN). There is a need for a mechanism to control the route optimization authorization feature. 
       SUMMARY 
       [0022]    Embodiments include a new route optimization authentication protocol. The current Mobile IPv6 protocols do not allow for optional control over the use of route optimization. Various embodiments allow for system control over whether route optimization is allowed or not allowed. The conditional allowance of route optimization solves several billing and security issues by allowing the system to impose appropriate charges for the route optimization feature or prevent route optimization where message flow (using care-of addressing) needs to be monitored through the home network. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The objects and features of various embodiments will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements and in which: 
           [0024]      FIG. 1  is a diagram of a mobile IP wireless communication network compatible with Mobile IPv6; and 
           [0025]      FIG. 2  is the message flow of one or more embodiments for authentication and authorization of the Mobile Node using the route optimization authentication option. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]      FIG. 1  shows an embodiment for a mobile IP cellular communication network compatible with Mobile 1Pv6 using various embodiments discussed herein. A home network  105  consists of an Authentication, Authorization, and Accounting server  110 . The server  110  is connected to a buss line  113  to a home agent (HA)  115 . Communication link  117  connects the HA  115  to the Internet  120 . A communication link  121  connects the Internet  120  to a Foreign Agent  130  on a visited network  125 . Communication link  129  connects the Foreign Agent  130  to the Mobile Node (MN)  135 , and this communication link includes a wireless connection. The Mobile Node  135  can be a communication device, such as a cellular phone, a computer, a router, a personal data assistant (PDA) and handheld terminal, or some other type of host. 
         [0027]    The Mobile Node  135  is associated with the Home Agent  115 . Information packets sent to the Mobile Node  135  on the home network  105  are routed to the Mobile Node  135  while linked to the foreign network  125 . The Home Agent  115  stores an address association in its memory corresponding to the location of the Mobile Node  135  on the foreign network  125 . The address association includes the Internet Protocol address of the Mobile Node  135  on the home network  105  and the care-of address corresponding to the topological location of the Foreign Agent  130 . As the Mobile Node  135  moves from network to network, the various routing tables and other data tables must be updated to maintain communication with the Mobile Node  135  thereby ensuring the correct routing of information packets. 
         [0028]    When Mobile Node  135  movement results in a change in connectivity, the Mobile Node&#39;s  135  care-of address must be updated so that the correct router associations on both the Home Agent  115  and the Foreign Agent  130  are maintained. Hand-off procedures involve assignment of a care-of address for the Home Agent  115  to transmit an information packet through the Internet  120 , so that the Foreign Agent  130  can route the information packet to the connected Mobile Node  135 . 
         [0029]    A correspondent node (CN)  145  is coupled to the Home Agent (HA)  115  through communication link  150 . When communicating to the MN  135 , the correspondent node (CN)  145  initially communicates through the Home Agent (HA)  115 . The Home Agent (HA)  115  uses care-of address and packet encapsulation to forward packets to the MN  135  through the visited network  125 . 
         [0030]    Route optimization allows the CN  145  to communicate directly with the MN  135  over communication link  153 , instead of communicating indirectly with MN  135  through communication link  150 , Home Agent  115 , and the care-of forwarding process through the visited network  125 . Such route optimization is always implemented as a mandatory feature in Mobile IPv6, but the route optimization needs to be controlled and authorized so that billings to the user can be adjusted if route optimization is allowed and security and monitoring features can be invoked by disallowing route optimization. By disallowing the route optimization, all messages between the correspondent node (CN)  145  and the mobile node (MN)  135  can be monitored at the home network  105 . 
         [0031]    In this manner, the route optimization authorization can be selectively activated or disallowed by the system protocols to accommodate these billing and security requirements of the system. The increased flexibility added to the system through the use of the discussed embodiments is significant, and the benefits achievable from the use of the discussed embodiments are substantial. 
         [0032]      FIG. 2  shows one embodiment of a message flow for authorization of route optimization during the authentication and authorization initialization process. Embodiments may also include a route optimization authorization as a purely periodic function or in response to a user or system initiated protocol. For the purposes of the discussed embodiments, the route optimization authorization will be explained in relation to the initialization process shown in  FIG. 2 . 
         [0033]    As set forth therein, in step  205 , the MN  135  generates a Binding Update (BU) message and transmits that message to the home agent (HA)  115 . The BU  205  message tells the Home Agent (HA)  115  where the mobile node (MN)  135  is located. This location information would provide the Home Agent (HA)  115  with information on the visited network  125  supporting the communications to the MN  135 . The care-of address information for this visited network  125  would be provided to the Home Agent (HA)  115 , so that message forwarding can be conducted by the Home Agent  115 . 
         [0034]    The Home Agent  115  will transmit an authorization (AUTH) message  210  over communication link  113  to the AAA server  110 . The AAA server  110  is the authorization, authentication and accounting server that maintains (as its name would imply) authentication information, accounting information, and authorization information for users associated with home network  105 . The authorization (AUTH) message  210  will inquire from AAA server  110  whether the Mobile Node MN  135  initiating the Binding Update message  210  has been authenticated, and if so, if that MN  135  has an active account that is authorized to support mobile communications under Mobile IPv6 and whether route optimization is permitted to that Mobile Node (MN)  135 . Also, accounting information and status codes can be provided for particular mobile nodes on the system. The authorization AUTH  210  message contains all the required identification information for the AAA server  110  to conduct its analysis of the Mobile Node MN  135 . 
         [0035]    In response to the authorization AUTH  210  message, the AAA server  110  will respond to the Home Agent  115  with an authorization AU Reply message  215 . The AU Reply  215  message will provide the Home Agent  115  with an indicator of whether route optimization is authorized under Mobile 1Pv6 protocols, and whether or not route optimization is authorized for the mobile node MN  135 . 
         [0036]    If the communication protocol does not support communication to the Mobile Node MN  135  under Mobile 1Pv6, then route optimization will not be supported. The AAA server  110  will indicate that route optimization is not supported in the AU Reply message  215 . The AU Reply  215  may include a separate attribute that indicates “MIPs=No” to show that Mobile IPv6 communications are not supported by the system for communications with Mobile Node MN  135 . 
         [0037]    If the communication protocol supports communication to the Mobile Node (MN)  135  under Mobile 1Pv6, then the AAA server  110  will designate in the AU Reply message  215  whether route optimization is authorized or not. The AU Reply message  215  could include a separate attribute in the AU Reply  215  that indicates “MIPs=Y” to show Mobile IPv6 protocols support communication with Mobile Node  135  and RO=Y to indicate that route optimization is supported for communications to Mobile Node MN  135 . If route optimization is not supported to Mobile Node MN  135  for this type of communication, then the attributes would be set at “MIPs=Y” and “RO=N” to show Mobile 1Pv6 is supported, but route optimization is not authorized to Mobile Node MN  135 . 
         [0038]    As an alternative, there are codes in the AU Reply  215  that can be set to indicate whether route optimization is authorized or not authorized. For instance, a status code could be set to a value of less than 128 if route optimization is not authorized or above 128 if route optimization is authorized. This code would use as pre-existing attribute value in the AU Reply  215  packet, instead of creating a new attribute or modifying the existing data packet structure used in Mobile IPv6 protocols. Other types of codes or flags can be used in the existing packet structure of the Mobile IPv6 packet to indicate whether Mobile 1Pv6 is supported and whether or not route optimization is authorized. 
         [0039]    After receiving the AU Reply  215  message, the home agent  115  communicates a Binding Update acknowledgement (BU Ack)  220  message to the Mobile Node  135 . This BU Ack  220  message includes an indication of whether route optimization is supported or not. The indication of route optimization authorization can be shown as a separate attribute (e.g. “R.O. Y” or “R.O.=N”) for a Mobile 1Pv6 packet or as a value for a pre-existing attribute (attribute&lt;128 means “RO No” or Attribute&gt; 128  means “RO=Yes”) in the Mobile 1Pv6 packet. 
         [0040]    As an additional option, a code message can be communicated to the Mobile Node MN  135  from the home agent  115  to indicate whether route optimization is authorized and supported. The code message can indicate “MIPv6 authorization successful, but Route Optimization is Not Allowed,” “MIPv6 authorization not successful,” or “MIPv6 authorization successful and Route Optimization Allowed” depending on the communication protocol supported and the route optimization authorization. 
         [0041]    If communications involving the Mobile Node  135  are supported under Mobile IPv6 and Route Optimization is authorized, then route optimization signaling messages (MSG  1 , MSG 2 , MSG 3  and MSG 4 ) are transmitted between the MN  135 , the home agent HA  115 , and the correspondent node CN  145  to initialize and initiate the route optimization communications. Specifically, if route optimization is authorized based on the receipt of the BU Ack  220  message, the Mobile Node  135  responds to the Home Agent HA  115  with MSGI at step  222 . The Home Agent HA  115  transmits a message MSG 2   225  to the correspondent node  145 , and the correspondent node  145  responds to the Home Agent HA  115  with message MSG 3   230 . The home agent HA  115  then signals the Mobile Node MN  135  with message MSG 4  to complete the route optimization initialization communications. Thereafter, the route optimization communication traffic is transmitted directly between the Mobile Node MN  135  and the correspondent node CN  145  as shown in step  240 . If route optimization is not permitted, then the communication traffic to the Mobile Node MN  135  from the correspondent node CN  145  is transmitted through the home agent HA  115  as shown in step  245 . 
         [0042]    While embodiments have been particularly shown and described with respect to various embodiments, it will be readily understood that minor changes in the details of various embodiments may be made without departing from the spirit of the embodiments.