Abstract:
A system and method for dynamic egress routing through a default gateway in a network is disclosed. One aspect of the present invention includes providing a default gateway that manages routes to Internet egress points for a client. The default gateway includes a list of Internet egress points that correspond to the default gateway. A metric is applied to the list to determine the optimal path to an Internet egress point. The default gateway uses the optimal path to manage Internet access routing for the client. Another embodiment includes a system for managing routing to Internet egress points on a network having a default gateway configured to route data packets between the Internet egress points and a client. The default gateway determines the optimal path to the Internet egress points.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present invention is related to a patent application having Ser. No. ______, entitled: “System and Method for Expanding the Range of a Mesh Network”, filed concurrently with this application and having an attorney docket number 50037.0314US01. The present invention is also related to a patent application having Ser. No. ______, entitled: “System and Method for Using a Hop Limited Cast for Internet Egress Point Selection”, filed concurrently with this application and having an attorney docket number 50037.0316US01. The related applications are assigned to the assignee of the present patent application and are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Wireless communication between devices is becoming a more prevalent and accepted method of providing network communication. Wireless communication may take place on a mesh network comprised of mesh boxes or mesh-configured computing devices referred to as mesh nodes. A mesh network is a network topology in which mesh nodes are connected by self-forming connections as mesh nodes enter the network. In a large-scale well-connected mesh network, users expect to access any part of the mesh network from any other part of the mesh. Stated another way, users want to access the same resources from their desktop at home, from their laptop, from a coffee shop, from a kiosk at the library, or from a tablet at school. Assuming all the locations are connected to the same mesh network, this expectation of connectivity is reasonable.  
         [0003]     Wireless communication, however, may have several limitations that effect communication on a mesh network. These limitations may arise from the routing protocol of the mesh network. In order to communicate information between two distant mesh nodes, mesh nodes route through intermediate mesh nodes. A data packet routed through a mesh node is generally referred to as a hop. For example, if a data packet must traverse three mesh nodes before reaching a destination mesh node, the data packet will make two hops. Also, a data packet may have several paths through the mesh available for routing. Each of the several paths may have different connectivity. For example, one path may require a data packet to make eight hops while another path may only require two hops. In general, as hops on the mesh increase, latency increases; hence, the communication path between two mesh nodes cannot practically scale beyond a limited number of hops before connectivity falls below user expectations. Accordingly, there exists a need to identify the path through a mesh network with the fewest number of hops in order to minimize latency for devices communicating on a mesh network.  
       SUMMARY OF THE INVENTION  
       [0004]     Aspects of the present invention relate to a system and method for dynamic egress routing through a single default gateway in a mesh network. One aspect of the present invention includes a computer-implemented method for managing routing to Internet egress points on a network. By using a list of Internet egress points, a default gateway manages routes for a client. A metric is then applied to the list of Internet access points to determine the most optimal path. The optimal path is used to manage Internet access routing for the client.  
         [0005]     Another aspect includes a computer-readable medium that has computer-executable instructions for managing routing to Internet egress points on a network. The instructions include obtaining a list of paths from a default gateway to an Internet egress point. The instructions also include determining an optimal path and using the optimal path to manage Internet access routing for a client.  
         [0006]     Yet another aspect includes a system for managing routing to Internet egress points on a network. The system includes a default gateway configured to route data packets between the Internet egress points and a client The default gateway determines the optimal path to the Internet egress points. These and other embodiments will be evident as more fully set forth in the detailed description and claims below.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  illustrates an exemplary computing device that may be used in one exemplary embodiment of the present invention.  
         [0008]      FIG. 2  illustrates an exemplary mobile device that may be used in one exemplary embodiment of the present invention.  
         [0009]      FIG. 3  illustrates an exemplary mesh network that may be used in one exemplary embodiment of the present invention.  
         [0010]      FIG. 4  illustrates an exemplary mesh network that may be used in one exemplary embodiment of the present invention  
         [0011]      FIG. 5  illustrates a logical flow diagram of one aspect of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0012]     Embodiments of the present invention now will be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments for practicing the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Among other things, the present invention may be embodied as methods or devices. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. The following detailed description is, therefore, not to be taken in a limiting sense.  
         [0000]     Illustrative Operating Environment  
         [0013]     Referring to  FIG. 1 , an exemplary system for implementing the invention includes a computing device, such as computing device  100 . In a basic configuration, computing device  100  typically includes at least one processing unit  102  and system memory  104 . Depending on the exact configuration and type of computing device, system memory  104  may be volatile (such as RAM), non-volatile (such as ROM, flash memory, and the like) or some combination of the two. System memory  104  typically includes an operating system  105 , one or more applications  106 , and may include program data  107 . This basic configuration is illustrated in  FIG. 1  by those components within dashed line  108 .  
         [0014]     Computing device  100  may also have additional features or functionality. For example, computing device  100  may also include additional data storage devices (removable and/or non-removable) such as, for example, magnetic disks, optical disks, or tape. Such additional storage is illustrated in  FIG. 1  by removable storage  109  and non-removable storage  110 . Computer storage media may include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules or other data. System memory  104 , removable storage  109  and non-removable storage  110  are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computing device  100 . Any such computer storage media may be part of device  100 . Computing device  100  may also have input device(s)  112  such as keyboard, mouse, pen, voice input device, touch input device, etc. Output device(s)  114  such as a display, speakers, printer, etc. may also be included. All these devices are known in the art and need not be discussed at length here.  
         [0015]     Computing device  100  also contains communications connection(s)  116  that allow the device to communicate with other computing devices  118 , such as over a network or a wireless mesh network. Communications connection(s)  116  is an example of communication media. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. The term computer readable media as used herein includes both storage media and communication media.  
         [0016]     In one embodiment, applications  106  further include an application  120  for implementing mesh networking functionality in accordance with the present invention. The functionality represented by application  120  may be further supported by additional input devices,  112 , output devices  114 , and communication connection(s)  116  that are included in computing device  100  for establishing and maintaining a mesh network.  
         [0017]      FIG. 2  illustrates a mobile computing device that may be used in one exemplary embodiment of the present invention. With reference to  FIG. 2 , one exemplary system for implementing the invention includes a mobile computing device, such as mobile computing device  200 . The mobile computing device  200  has a processor  260 , a memory  262 , a display  228 , and a keypad  232 . The memory  262  generally includes both volatile memory (e.g., RAM) and non-volatile memory (e.g., ROM, Flash Memory, or the like). The mobile computing device  200  includes an operating system  264 , such as the Windows CE operating system from Microsoft Corporation or other operating system, which is resident in the memory  262  and executes on the processor  260 . The keypad  232  may be a push button numeric dialing pad (such as on a typical telephone), a multi-key keyboard (such as a conventional keyboard). The display  228  may be a liquid crystal display, or any other type of display commonly used in mobile computing devices. The display  228  may be touch-sensitive, and would then also act as an input device.  
         [0018]     One or more application programs  266  are loaded into memory  262  and run on the operating system  264 . Examples of application programs include phone dialer programs, email programs, scheduling programs, PIM (personal information management) programs, word processing programs, spreadsheet programs, Internet browser programs, and so forth. The mobile computing device  200  also includes non-volatile storage  268  within the memory  262 . The non-volatile storage  268  may be used to store persistent information which should not be lost if the mobile computing device  200  is powered down. The applications  266  may use and store information in the storage  268 , such as e-mail or other messages used by an e-mail application, contact information used by a PIM, appointment information used by a scheduling program, documents used by a word processing application, and the like.  
         [0019]     The mobile computing device  200  has a power supply  270 , which may be implemented as one or more batteries. The power supply  270  might further include an external power source, such as an AC adapter or a powered docking cradle that supplements or recharges the batteries.  
         [0020]     The mobile computing device  200  is shown with two types of external notification mechanisms: an LED  240  and an audio interface  274 . These devices may be directly coupled to the power supply  270  so that when activated, they remain on for a duration dictated by the notification mechanism even though the processor  260  and other components might shut down to conserve battery power. The LED  240  may be programmed to remain on indefinitely until the user takes action to indicate the powered-on status of the device. The audio interface  274  is used to provide audible signals to and receive audible signals from the user. For example, the audio interface  274  may be coupled to a speaker for providing audible output and to a microphone for receiving audible input, such as to facilitate a telephone conversation.  
         [0021]     The mobile computing device  200  also includes a radio interface layer  272  that performs the function of transmitting and receiving communications, such as radio frequency communications. The radio interface layer  272  facilitates wireless connectivity between the mobile computing device  200  and the outside world, via a communications carrier or service provider. Transmissions to and from the radio interface layer  272  are conducted under control of the operating system  264 . In other words, communications received by the radio interface layer  272  may be disseminated to application programs  266  via the operating system  264 , and vice versa.  
         [0022]     In one embodiment, applications  266  further include an application  280  for implementing mesh networking functionality in accordance with the present invention. The functionality represented by application  280  may be further supported by structure in radio interface layer  272  that is included in mobile device  200  for establishing and maintaining a mesh network.  
         [0023]      FIG. 3  illustrates a mesh network  300  that may be used in one exemplary embodiment of the present invention. Mesh network  300  may comprise any topology of mesh nodes, Internet service providers and communication media. Also, the mesh network  300  may have a static or dynamic topology without departing from the spirit and scope of the present invention.  
         [0024]     The mesh network  300  includes one or more Internet service providers  310 , which provide Internet access points for one or more mesh nodes. Each mesh node may comprise any device that is connected to the mesh network  300 . The mesh node may transmit and receive data packets and also may pass data packets to other mesh nodes in accordance with the routing protocol of the mesh network  300 . The mesh node may be a fixed device or a mobile device. For example, the mesh node may include a computing device  312  that is similar to computing device  100  described above in conjunction with  FIG. 1 . The mesh node may also include a mobile computing device  314  that may be similar to mobile computing device  200  described above in conjunction with  FIG. 2 . Other embodiments may include other configurations of mesh nodes. For example, a mesh node may include a dedicated computer that only routes data packets from one mesh node to another such as the mesh box  316 .  
         [0025]     In one exemplary embodiment of the present invention, the mesh network  300  has a network topology in which mesh nodes are connected with several redundant connections between the mesh nodes. The mesh network  300  may include a full mesh where every mesh node is connected to every other mesh node in the mesh network. Mesh network  300  may also include a partial mesh topology where some mesh nodes are organized in a full mesh and other mesh nodes are only connected to one or two other mesh nodes. Other mesh topologies may include one or more subnets connected to the mesh network. These subnets may have a plurality of clients connected thereto. The various topologies for the mesh network  300  are endless and will not be further set forth herein.  
         [0026]     Reference number  318  indicates communication media between the mesh nodes. By way of example, and not limitation, communication media  318  may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Reference number  320  indicates communication media between Internet service provider  310  and one or more of the mesh nodes. The communication media  320  may include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media.  
         [0027]     In the mesh network  300 , mesh nodes may transmit and receive data packets from other mesh nodes and/or from the Internet. Routing tables typically determine what path a data packet traverses through the mesh network. The routing of a data packet is commonly determined at a source node. Stated another way, the node sending a data packet may determine the route a data packet takes through the mesh network. A data packet routed from a mesh node to reach another mesh node is typically referred to as a “hop.” For example, if mesh node  314  desires to transmit a data packet to mesh node  316 , the routing tables accessible to mesh node  314  may indicate routing will take place through mesh node  322 . Accordingly, the data packet will make two hops (node  314  to node  322  and node  322  to node  316 ). In general, latency increases proportionally with the number of hops a data packet must make to reach a mesh node. Also, routing tables may indicate several available paths for a data packet to traverse to reach a destination. Routing tables may also indicate that a destination mesh node is inaccessible because the number of hops is too great. Therefore, it is advantageous for each node to have access to routing tables with the most optimal path between nodes. It is also advantageous for each node to have access to routing tables that provide greater access to the mesh network.  
         [0000]     Illustrative Embodiments of Dynamic Egress Routing Through A Single Default Gateway  
         [0028]      FIG. 4  illustrates an exemplary mesh topology for one embodiment of the present invention. As stated above, the mesh network may have various topologies without departing from the spirit and scope of the present invention. The mesh topology in  FIG. 4  is for exemplary and explanatory purposes only and not for purposes of limiting the scope of the present invention as will be fully set forth in the claims below.  
         [0029]     Mesh network  400  includes mesh nodes  404 ,  406  and  408 . Mesh node  404  is referred to herein as default gateway  404  in that it provides clients  402  a default gateway to the mesh network  400 . Mesh nodes  406  and  408  are referred to herein as egress mesh nodes  406  and  408  in that they provide Internet egress points in the mesh network  400 .  
         [0030]     Clients  402  may include any type of computing device or mobile computing device capable of communication with a network. The clients  402  may be configured as a subnet wherein the subnet connects to a default gateway  404 . The subnet may include any type of topology set forth above in conjunction with  FIG. 3 . When clients  402  attempt to communicate with the Internet, the clients  402  use default gateway  404  to route data packets to the Internet. Default gateway  404  determines how to route communications between the clients  402  and the Internet as will be more fully set forth below.  
         [0031]     The clients  402  will request the address of the default gateway  404  and the default gateway  404  will provide each client  402  with its address. The request may include a DHCP request (dynamic host configuration protocol) and the address may include an Internet Protocol (“IP”) address and/or a default gateway address. Other processes are contemplated as long as data packets are capable of being routed between the clients  402  and the default gateway  404 . When clients  402  attempt to communicate with the Internet, the default gateway  404  will decide which egress mesh node  406  or  408  to route through in order to reach the Internet. For example, in  FIG. 4 , egress mesh node  406  is three hops from default gateway  404  and egress mesh node  408  is four hops from default gateway  404 . If the decision of default gateway  404  was based solely on hop count, routing would occur through egress mesh node  406 . However, hop count may be only one of many parameters to determine an optimal route to the Internet as is more fully described below in conjunction with  FIG. 5 .  
         [0032]      FIG. 5  represents a logical flow diagram of one embodiment of the present invention. As an illustration, the process  500  may occur at default gateway  404 ; however, it is contemplated that any mesh node on a mesh network may perform the process  500 . The process  500  starts at starting block  502  and flows to block  504  where an egress point descriptor is selected from an Internet egress point store  506 . The egress point descriptor may include the address and/or route to an Internet egress point. It is contemplated that the egress point descriptor may comprise other data to describe an egress point of the mesh network. Also, the egress point descriptor store may include one or more egress point descriptors that describe one or more routes to an egress point. For example, default gateway  404  may include an egress point descriptor store having one or more stored Internet egress point descriptors such as an egress point descriptor of the egress point associated with the egress mesh node  406 . Default gateway  404  may then select an egress point descriptor from the store  506 . The store  506  may include any type of storage so long as at least default gateway  404  has access to the store  506 .  
         [0033]     Block  508  indicates the step of calculating the route metric for a route to an Internet egress point. Generally, the route metric may be calculated in various ways depending on the routing protocol of the mesh network. In one embodiment, the routing metric includes a rating or identifier that indicates the efficiency of a route to an Internet egress point. The routing metric may consider several factors in order to rate a path to an Internet egress point. For example, such factors may include the hop count or latency between the default gateway and the Internet egress point associated with the egress mesh node  406 . Other factors may include the amount of interference, the signal strength, the transmission capacity, the casting capacity and/or the throughput between the default gateway  404  and the Internet egress point associated with egress mesh node  406 .  
         [0034]     In one embodiment, the route metric calculation takes advantage of the MCL protocol (mesh connectivity layer). Stated another way, the MCL acts as an optimal route calculation engine; the MCL does not need to actually route the data. In such a situation, default gateway  404  will select an egress point descriptor as identified by block  504 . The MCL may then calculate the routing metric through Link Quality Source Routing. Other protocols are contemplated as long as the routes to the Internet egress points can be rated. Once the egress routing metric has been calculated, the default gateway  404  is given access to the egress routing metric. The route identified by the metric may be stored in a hierarchy of routes or any other type of store known in the art. The process  500  continues to block  510 .  
         [0035]     Block  510  indicates the step of selecting the optimal route through the mesh network. The optimal route may be indicated by the route metric. Again, this selection may occur by selecting the optimal route from a hierarchy of routes. This selection may also include selecting the optimal route from a plurality of unsorted routes. The process  500  continues to block  512 .  
         [0036]     Block  512  identifies the step of determining if routing is permitted to the Internet egress point having the optimal route. A default gateway may send a request to the optimal egress point for permission to use the optimal egress point. In the situation where the optimal egress point is already serving several clients, the optimal egress point may deny permission to route through the egress point. For example, default gateway  404  may send a request to egress mesh node  406  asking permission to use the Internet service provider associate with egress mesh node  406 . Egress mesh node  406  may be serving fifteen clients at the time of the request. Accordingly, egress mesh node  406  may deny default gateway  404  access to the Internet egress point. In such a situation the process  500  selects a second egress route and continues by looping back to step  510 . In one embodiment of the present invention, the second egress route is the second most optimal route to the Internet egress point. This process continues until routing to an Internet egress point is permitted. Once routing is permitted, the process  500  continues to block  514  where the routing tables are updated with the most optimal route. The default gateway may then use the routing tables to optimally route information between the Internet and the clients.  
         [0037]     The process  500  may be static or dynamic without departing from the spirit and scope of the present invention. Stated another way, the process  500  may only run during predetermined intervals, such as when a client attempts to communicate with the Internet or a node on the mesh network. The process  500  might also be dynamic, meaning that the routes could be continuously updated as the characteristics of the mesh network change.  
         [0038]     The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.