Accessing local network resources in a multi-interface system

A method is provided for selectively routing data packets on a client device having of plurality of network interfaces for communicating over a network. The method comprising the following steps. It is determined if the data packets should be routed to a network server accessible by a corresponding one of the network interfaces to access local resources offered thereon. If the data packets should be routed to the network server, the data packets are routed directly to the network server via the corresponding network interface. Otherwise, the data packets are routed via a default route. A client device configured to implement the method is also provided.

The present invention relates generally to multi-interface communication systems and specifically to accessing network resources that are not available over a default network interface when implementing such systems.

BACKGROUND

Multi-interface communication systems allow client devices to use multiple network interfaces as if they were a single network interface. This is achieved by providing a network component that acts as an agent for the client device. The client device can be configured to use any number of network interfaces at the same time, as well as move traffic between interfaces.

Examples of multi-interface communication systems are provided in U.S. patent application Ser. No. 13/004,652, titled “Communication Between Client and Server Using Multiple Networks” by Manku et al. (hereafter referred to as “Manku”) and U.S. Pat. No. 7,539,175, titled “Multi-Access Terminal with Capability for Simultaneous Connectivity to Multiple Communication Channels” by White et al.

In the multi-interface communication system, network traffic generated by applications running on the client device, or network traffic generated by other systems that is routed through the client device, is directed to a virtual network interface using routing rules. The traffic is encapsulated using one of a number of different encapsulation protocols. Using one of a variety of scheduling algorithms, the encapsulated traffic is sent out on one or more of the network interfaces, destined for an endpoint of the system. In many cases, this endpoint is in a different network location than a traditional network endpoint, had the client device used the network interface directly, as is standard in the art. Unfortunately, this process prevents the client device from accessing network resources that are only accessible via networks that are connected to one of the non-default network interfaces independent of the encapsulation system. These resources are termed local resources. Examples of local resources include captive portals, protected servers, application marketplaces, network information pages, and many others.

SUMMARY OF THE INVENTION

The present invention allows applications on clients running multi-interface software or hardware, or unmodified client devices located behind a client router running multi-interface software or hardware, to readily access resources that are only accessible through a network interface that is not the default interface for the system without requiring the application to have a specialized configuration.

In accordance with an aspect of the present invention, there is provided a method by which local network resources can be accessed transparently by applications in a multi-interface network encapsulation system.

Also in accordance with a further aspect of the present invention, there is provided a method by which local network resources available on a non-default network interface can be accessed transparently by applications in a multi-interface operating system.

In accordance with an aspect of the present invention, there is provided a method for selectively routing data packets on a client device having of plurality of network interfaces for communicating over a network, the method comprising the steps of: determining if the data packets should be routed to a network server accessible by a corresponding one of the network interfaces to access local resources offered thereon; if the data packets should be routed to the network server, routing the data packet directly to the network server via the corresponding network interface; otherwise, routing the data packets via a default route.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For convenience, like numerals in the description refer to like structures in the drawings. Referring toFIG. 1, a standard network environment is illustrated generally by numeral100.

The network environment100comprises a client device102, a first access point104, a second access point106, a network108, first and second network servers109aand109b, and a target server110. The client device102connects to the first network server109awhen using the first network access point104, and the network server109ais only available to client102when communicating using the first access point104. That is, network server109acannot be accessed from the second access point106. The client device102connects to the second network server109bwhen using the second network access point106, and the network server109bis only available to client102when communicating using network access point106. In this diagram, both network server109aand network server109bare examples of local network resources.

In the present embodiment, the network108is a Wide Area Network (WAN) such as the Internet. However, as is known the art, the network108can be comprised of a series of interconnected networks, depending on the implementation. In other scenarios, it may be a single network, a private network, or other non-typical network deployments.

The client device102can be a personal computing device such as a portable computer, tablet computer, smartphone, personal digital assistant (PDA) or the like. Alternatively, the client device102can be a computing device, such as a modem or a router, to which the personal computing device communicates. The client device102is configured with a first network interface and a second network interface for transmitting data to the first network server109aand the second network server109bvia the first access point104and the second access point106, respectively.

The first access point104and the second access point106can be any access points, such as Ethernet, Wi-Max, Digital Subscriber Loop (DSL), cable, satellite, cellular, Wi-Fi and the like. For ease of the explanation only, the first access point104is a cellular base station for communicating with the client device102over a cellular network. As is known in the art, the cellular base station104provides a data packet service such as GSM-based High Speed Packet Access (HSPA).

Similarly, for ease of explanation only, the second access point106is a Wi-Fi access point. The Wi-Fi access point106can be viewed as a Wireless Local Area Network (WLAN) that provides a gateway to the network108.

The target server110is a remote computing device from which the client device102may request information and to which the client device102may transmit information via the network108. The target server110may be a web server or any other device, such as a mail server, SIP server, and the like, connected to the network108, with which the client device102wishes to communicate. Target server110is accessible via either the first access point104or the second access point106.

Referring toFIG. 2, a multi-interface network environment as described by Manku is illustrated generally by numeral200. The multi-interface network environment200further comprises a proxy server209. The client device102can connect to the network108via one or both of the first network access point104or the second network access point106in order to communicate with the proxy server209. Traffic is encapsulated by a virtual interface on the client device and scheduled for transmission using corresponding ones of the network interfaces. Since the data can be broken into packets or segments and scheduled for transmission to the proxy server209via both the first access point104and the second access point106, the overall bandwidth available to the client device102can be improved.

The proxy server209is a server configured to receive data from the client device102via both the first access point104and the second access point106, reassemble it, and transmit it to the target server110. The proxy server209is also configured to receive data from the target server110and transmit it to the client device102via both the first access point104and the second access point106.

It will be appreciated that a tunnel212is created between the client device102and the proxy server209. The tunnel212includes the traffic sent over both the first access point104and the second access point106. As such, the traffic in this implementation passes through the proxy server209before reaching the target server110. The traffic is unable to reach the first or second network servers109aand109bas described with reference toFIG. 1because proxy server209is not able to reach either network server109aor109b.

Thus local resources provided by the first and second network servers109aand109bmay not be accessible to the client device. For example, consider that the second network server109bimplements a captive portal. Captive portals prevent traffic flow until predefined requirements are satisfied by the user, typically through their web browser. Accordingly, the captive portal can be used to deny the client device102access to the network108via the Wi-Fi access point106until the user enters validation credentials or payment information. If the data is unable to reach the second network server109bbecause it is passing through a proxy server209that is not able to communicate with the second network server109b, the client device102may not be able to pass data through the Wi-Fi access point106and it may not be apparent to the user why this is the case.

Thus, routing logic is provided at the virtual interface of the client device102. The routing logic is configured to determine whether the traffic sent from an application executing on the personal computing device is to be encapsulated by the virtual interface and transmitted across one or more of the multiple interfaces or sent directly to the network interface104or106for transmission, thereby bypassing the encapsulation system.

Referring toFIG. 3, software modules executing on the client device102in accordance with one embodiment of the invention are illustrated generally by numeral300. The software modules include standard applications302, dedicated applications304, a plurality of web proxies306, a packet router308, a virtual interface310, and a plurality of network interfaces312. The network interfaces312are the components of the client device102that connect to the network access points104and106as illustrated inFIG. 1.

The standard applications302are configured to transmit data across the network108using the multi-interface system. Accordingly, the packet router308is configured to transmit data packets from the standard applications302to the virtual interface310for encapsulation and scheduling across the plurality of network interfaces312.

The dedicated applications304are configured to transmit data to one of the web proxies306. Each of the web proxies306are configured to correspond with one of the network interfaces312. Thus, the web proxy306for which the dedicated application304is configured to transmit data is selected based on the target network interface312. Further, the web proxies306use standardized proxy protocols, like SOCKS for example, to communicate with the preconfigured applications304, thus allowing standard network libraries to be used. Each web proxy306can support many preconfigured applications304, allowing multiple preconfigured applications to access local network resources at any time.

The packet router308includes a routing table and is configured to receive data from the web proxies306and transmit it to the corresponding network interface312, bypassing the virtual interface310. Thus, the dedicated applications304can transmit data outside of the multi-interface system.

Continuing the previous example of a captive portal being used to validate the user on a Wi-Fi network, a dedicated web-browser can be provided to authenticate the user of the client device102to a Wi-Fi access point. When the client device102initially attempts to establish a connection using the Wi-Fi interface, it determines that it is being directed to a portal using any one of a number of known portal detection schemes. The user is notified that the connection to the Wi-Fi access point cannot be established and is directed to use the dedicated web-browser. Using the dedicated web-browser, the data is transmitted, via the corresponding web proxy306, to the packet router308. The packet router308identifies the data as coming from the web proxy306associated with the Wi-Fi interface312and routes the data accordingly. Since the data bypasses the virtual interface310, the user is able to authenticate him or herself and the client device102can establish the connection using the Wi-Fi interface. From this point forward, the user can use the standard applications302, unless it is desired to access other local resources provided by the network server109b. During this time, other standard applications302continue to use the virtual interface310without interruption. That is, traffic will continue to be transmitted to the 3G interface312until the Wi-Fi interface312can establish the connection with the Wi-Fi access point.

Other dedicated applications304can be used to access the network resources in a similar manner to the dedicated web-browser. For example, instead of a web proxy, other application protocols could be supported by implementing proxy applications for them. A similar infrastructure to that described above, including a dedicated application configured to communicate with an application-specific proxy, could be used to communicate with the packet router308.

Referring toFIG. 4, software modules executing on the client device102in accordance with a second embodiment of the invention are illustrated generally by numeral400. The software modules include applications402, a packet router408, a virtual interface410, and a plurality of network interfaces412. Unlike the previous embodiment, the present embodiment does not use web proxies306to offload traffic from the tunnel. Rather, in the present embodiment, the virtual interface is configured to rewrite the packet source address, thereby affecting the packet routing, as will be described below.

The virtual interface410is configured with a static, private Internet protocol (IP) address, such as 192.168.1.1/24 for example. The IP address assigned to the virtual interface is different from the IP addresses on all other network interfaces. In the present embodiment, the IP address for the Wi-Fi interface is 1.1.1.1/24 and the IP address for the 3G interface is 2.2.2.2/24.

The virtual interface410is also configured with a subnet mask that allows for a greater number of IP addresses than there are network interfaces412. Each of the network interfaces412are mapped to one of the addresses in the subnet defined by the subnet mask. For example, a Wi-Fi interface and a 3G interface could be mapped to IP addresses 192.168.1.2 and 192.168.1.3, respectively. These mapped addresses are not actually assigned to the network interfaces412, they are just stored in a mapping table in the virtual interface for later use when assigning packets to the network interfaces412.

The packet router408includes a routing table. Referring to Table 1 below, a sample routing table is shown. The packet router408is configured to route packets originating from IP address 192.168.1.2 to the Wi-Fi interface and packets originating from IP address 192.168.1.3 to the 3G interface. The packet router408is further configured to route packets to either the Wi-Fi interface or the 3G interface if that is, in fact, their actual destination. Remaining packets are routed to the virtual interface410.

In the context of an encapsulation system where encapsulated packets are passed to the proxy server209, the virtual interface410is able to communicate directly with the proxy server209over the network interfaces412by setting a specific route to the IP address of the proxy server209on the particular network interface412by which the traffic should leave. This is known as a host route. The host route forces all traffic destined to the IP address of the proxy server209out of the network interface412, because it is evaluated as being more specific than the default route, which directs all other traffic to the virtual interface410. The virtual interface410sets the host routes on startup, allowing it to communicate directly with proxy server209. If the client device102is expected to have multiple interfaces412, then the network server209will be configured with one IP address per network interface412, allowing the virtual interface410to communicate directly with proxy server209over each network interface412, as each network interface412will have a host route to a different IP address on the proxy server209. This allows the virtual interface410to select which network interface412the tunnelled traffic will leave by sending the packets destined to the relevant IP address specified in the host route on the relevant network interface412.

For example, if the proxy server209has been assigned the addresses 172.20.0.1 and 172.20.0.2, the client102would update the routing table shown in Table 1 to include 2 additional entries, as shown in Table 2. This forces any traffic destined to the first address, 172.20.0.1, to leave via the Wi-Fi interface, and any traffic destined to the second address, 172.20.0.2, to leave via the 3G interface. This makes it possible for the encapsulation system running on client102to schedule encapsulated packets out either the 3G or the Wi-Fi interface.

Further, each network interface412is configured with a network address translation (NAT) rule which specifies that all of the packets leaving the network interface412will have their source address replaced with the actual IP address of the network interface412. This rewriting substitution is performed by the client device102, using a firewall or other similar packet manipulation mechanism, for example.

When the application402sends a packet, the use of a default routing rule will cause the packet to be routed to the virtual interface410. Once the virtual interface410has received a packet, it processes the packet, classifies the packet into one of several categories, and then determines over which network interface412the packet should be sent.

If the packet does not need to be offloaded, it is encapsulated and scheduled as defined by the virtual interface410. If, however, the packet needs to be offloaded to access the local services provided by the network servers, the source address of the packet will be rewritten from the IP address assigned to the virtual interface410to the virtual IP address that has been mapped to the corresponding network interface412. Continuing the above example, the address for Wi-Fi would be rewritten to 192.168.1.2, and the address for 3G would be rewritten to 192.168.1.3.

Referring toFIG. 5a, a flow chart illustrating steps taken by the client device102to rewrite the source address for transmitting the packet is illustrated generally by numeral500. Continuing the previous example, at step502, a packet is received at the packet router408having a source IP address of 192.168.1.1. At step504, the packet is passed to the virtual interface410accordingly based on the routing information defined in Table 1.

At step506, it is determined whether or not the packet is to be offloaded from the tunnel. The process of determining whether to offload a packet from the tunnel can be controlled using a variety of settings that are configured via a policy applied either locally or remotely. It is possible to select packets that are to be offloaded from the tunnel based on the protocol type, the destination IP address of the packet, the originating application of the packet, the destination port of the packet, or any other field in the packet. It is also possible to use any attribute of the packet, including size, frequency of arrival, or other attribute not necessarily encoded in the packet.

Continuing the previous example of the Wi-Fi portal, it is possible for the network interface to look up the originating process of each connection, and map a custom web browser used to communicate with the portal to a specific IP address and port. This can be done by examining the list of open sockets and mapping the socket the packet came from with the process ID associated with the originating socket. Next, the process ID is mapped to the name of the application which is associated with this process ID. Using a specific application with a known piece of information about it, including name, user ID, binary image, or any other process identifier, makes it possible to determine if a packet is coming from a socket owned by the specific web browser that is handling the Wi-Fi portal communication. When the system sees packets matching this IP and port, it is possible to route them out the Wi-Fi interface while sending all other traffic over the existing 3G interface by rewriting the source address of this packet to the address that is mapped to the Wi-Fi interface, while rewriting the source address of all other packets to the address that is mapped to the 3G interface. Continuing the previous example, packets from the custom web browser handling Wi-Fi portal communications would have their source address rewritten to 192.168.1.2 to direct them to the Wi-Fi interface, while all other packets would have their source address rewritten to 192.168.1.3 to direct them to the 3G interface.

Extending on the previous mechanism of mapping a packet to a process, another example of mapping an incoming packet to a process could use a kernel module or kernel driver that would be able to determine the origin process of a packet. Mapping a packet to a process is known in the art, and is used by the Windows kernel to implement application-based firewalls. Yet another mechanism to accomplish this would be to extend the IP stack to add hooks to expose which process has created each socket. Further, it would be possible to replace the entire IP stack with one optimized to provide this information to the virtual interface for simplified packet to process matching.

If the packet is not to be offloaded, then at step508, the packet is encapsulated and scheduled to be transmitted across the tunnel. If the packet is to be offloaded to the Wi-Fi interface, then at step510the source IP address will be rewritten to 192.168.1.2 by the virtual interface410to make it appear that the packet originated from that IP address. This operation may require certain checksums to be recalculated, based upon the structure of a header containing the IP address that was changed.

At step512, the packet is sent back to the packet router408. The packet router408examines the new packet, determines that it originated from IP address 192.168.1.2, and passes the packet to the Wi-Fi network interface. At step514, the packet passes through the OS-specific NAT mechanism, and its source address is rewritten again, this time to contain the actual IP address of the Wi-Fi interface412. From this point on, the packet appears to have come directly from the Wi-Fi interface, and is transmitted on to the network108as normal.

Referring toFIG. 5b, a flow chart illustrating steps taken by the client device102to rewrite the source address for a received packet is illustrated generally by numeral550. At step552, after some period of time, a packet returns from the network108, and is received by the Wi-Fi interface. At step554the system determines that the packet matches a flow for which it is performing address rewriting. This is accomplished using an internal table that contains all outgoing flows that have been rewritten, and the packet is matched against this table. This precise step will vary based upon the implementation of the NAT, and the details of NAT design are known to those skilled in the art. The NAT changes the destination address of the arriving packet to the mapped IP address of the Wi-Fi interface, which is 192.168.1.2. At step556, once the address has been rewritten, the packet is passed to the packet router408. At step558, the packet router sends the packet to the virtual interface410, based on the routing table. At step560, the virtual interface410examines the packet, records any relevant information about the packet, and rewrites the destination address to be 192.168.1.1. At step562the packet is passed back to the packet router408, which recognizes that the packet is destined for an open application socket, and at step564sends the packet to the application402.

However, some operating systems may not be able to readily replace source and destination IP address as described above. Accordingly, in a third embodiment, IP header-fields other than the IP address can be used to manipulate routing decisions. For example, the Linux kernel enables packet routing based not only upon the IP address, but also on other fields such as the Terms of Service (ToS) fields in an IP packet. By mapping different values to the ToS fields, it is possible to route packets in a similar manner as discussed above with regard to IP address replacement. Thus, client devices102that do not support source address routing may be similarly configured, but using a different IP header field that is supported. This can be extended to include classifying packets based on any field in the packet, using Layer 7 inspection. Prepending a custom header, which is ignored by the network interface412, would make it possible to route the packet based on any field in the packet without modifying the packet itself.

Further, on some operating systems, it is possible to mark a packet in an out-of-band manner, that the packet router408would use to determine which interface412the packet should be sent to. This would enable the virtual interface410to route packets using any field in the packet in systems that might not otherwise support routing based upon source IP addresses.

In a fourth embodiment, the virtual interface410is set as a default interface for the client device102. Accordingly, the virtual interface410captures all of the traffic generated from or destined for the applications402and acts as a transparent protocol proxy. When a connection is made from a client application402to a destination server110, the virtual interface410will see the connection request message. Instead of forwarding this connection request on, the virtual interface410will respond to the client application402as if it were the destination server110. Concurrently, the virtual interface410will establish a connection to the destinations server110over one of the specific network interfaces. This connection request will be properly routed because the connection from virtual interface410will originate from the source of the network interface412which this connection has been determined to be assigned to. This assignment is performed in the same manner described in previous embodiments. The use of the previously discussed source address routes will ensure this packet is routed to the proper network interface. The virtual network interface410will then route any incoming data from application402over the newly established connection between virtual network interface410and the destination server110.

As an example of the above embodiment, when a TCP connection is made to a target server 8.8.8.8 by a web browser, the virtual interface410will receive a TCP SYN packet, and send a TCP SYN-ACK back to the application. At the same time, the virtual interface410will establish an independent TCP connection to the target server 8.8.8.8 originating from the Wi-Fi interface because this connection has been determined to be one with a captive portal. Once the web browser starts passing traffic to the virtual interface410, it will use the newly created TCP connection with 8.8.8.8 to pass the traffic to the server over the Wi-Fi network interface. It appears as though the virtual interface410initialized the connection from the perspective of the server 8.8.8.8, but from the application's perspective it is communicating directly with the server and not the virtual interface410.

In this embodiment, the virtual interface410will see all of the traffic that passes between the application402and the network server110. This allows the virtual interface410to record what each application402is doing, monitor communication behaviour for congestion, latency, and the like, and make advanced scheduling decisions to potentially move the communication to another network interface412if the observed network parameters suggest this is necessary. It is not sufficient for each application402to add a host route to the network server109out the specific interface412the application402wishes to use. In this case, if there exists a host route to the network server109out a specific network interface412, then the virtual interface410would not see any of traffic as it would pass directly out the specified network interface. This is because a host route takes precedence over the default route to the virtual interface410. Thus, the embodiment of using virtual interface410as an IP proxy instead of simply using host routes for every network server109enables the virtual interface410to see all of the packets without issue.

Optionally, the virtual interface410can probe out different network interfaces412to determine with which network interface412the destination server110is associated. If the client is attempting to communicate with a destination server110on a network different from the proxy server209, it is possible the destination server110may not available through the encapsulation tunnel. Accordingly, the traffic should be routed via the first access point104or the second access point106. It may also not possible to know a priori which of the first access point104or the second access point106can access the destination server110, if it can be access at all.

By having the virtual interface410act as a transparent protocol proxy, it will appear to the application402that a connection to the destination server110has been made. In the meantime, the virtual interface410attempts to connect to the destination server via the network interface412. If any of the network interfaces412successfully facilitate a connection to the destination server110, then the traffic can be exchanged with the application402. If none of the network interfaces are able to facilitate a connection with the destination server110, the virtual interface410sends a close message to the application402and it will appear to the application as if the destination server110closed the connection prior to sending any data. In both cases, it is transparent to the application402.

In a fifth embodiment a similar paradigm of capturing all of the outbound network traffic at the virtual interface410is described. However, instead of writing specialized routing rules to route packets to the proper network interfaces412, a kernel module is used to write packets directly to the network interface412. This behaviour uses the same metrics for identifying packets as belonging to a particular flow, however instead of manipulating the routing table in the packet router408to have the packet be sent to a specific network interface the kernel module is able to write the packet directly to the network interface driver using functions that are only exposed in the kernel of the operating system. This enables the system to bypass the routing decisions that are made, ensuring that the packets are sent out the proper network interface412without manipulating the routing table. Each packet has its source address modified prior to writing it to the network interface412, to ensure that the returning packets are properly processed by the virtual interface410before they continue on to the application402. The use of NAT is maintained, as the address rewriting rules are typically applied immediately before the packet is sent out network interface412. Since the source address was rewritten, once the returning packets have been translated through the NAT rule they are passed to the virtual interface410for inspection before they are passed on to the application402.

Further, in addition to multi-interface communications systems, client devices that are equipped with multiple network interfaces but only transmit on a single interface need to decide which interface will be used to transmit traffic. Traditional scheduling algorithms for multi-interface client devices simply select the lowest cost interface to use, and all traffic generated by the client device is sent out the lowest cost interface. Examples of this approach can be found in the Android, iPhone, and Windows Phone 7 network interface selection algorithm. In these systems, the operating system chooses the lowest cost interface, and then disables all the other available interfaces, making it appear to applications on the device that there is only a single interface. Unfortunately, this process prevents the client device from accessing network resources that are only accessible via networks that are connected to one of the network interfaces not selected for use. Here, the local resources are inaccessible not because the traffic is routed through an encapsulation system to a network endpoint that is independent of the client, but because the client is no longer connected to the other local networks due to the operation of the operating system. In this case, the cause of the inaccessibility is different, but the end result is the same; client devices may be denied access to resources they would otherwise be able to access.

Therefore, in a sixth embodiment, packets can be routed to one of the first access point104or the second access point106without the presence of a multi-interface communication system that uses encapsulation. Here, as in the previous embodiments, packets are read from a virtual network interface410and are scheduled across one of the available network interfaces412. However, instead of evaluating the rule506as to whether or not the packet should be offloaded from the tunnel, step504proceeds directly to step510whereby the source IP address of the packet is replaced to identify the target network interface of the device. This allows client applications running on a multi-interface network system to obtain the advantages of per-interface scheduling without requiring the presence of an encapsulation system. In this embodiment, it may be necessary for the virtual interface410to override the default behaviour of the operating system in order to keep all of the network interfaces412active. Thus, applications are able to access local network resources that would not otherwise be available due to the default behaviour of the network selection algorithm on devices not running a multi-interface encapsulation system.

In the embodiments described above, the routing logic is implemented as part of the virtual interface310,410. A skilled person in the art will appreciate that this is not a limitation. Rather, the routing logic may also be implemented on its own or as part of another device or module and is in communication with the virtual interface310,410to instruct it accordingly.

Using the foregoing specification, the invention may be implemented as a machine, process or article of manufacture by using standard programming and/or engineering techniques to produce programming software, firmware, hardware or any combination thereof.

Any resulting program(s), having computer-readable instructions, may be stored within one or more computer-usable media such as memory devices or transmitting devices, thereby making a computer program product or article of manufacture according to the invention. As such, the term “software” or “modules” as used herein is intended to encompass a computer program existent as instructions on any computer-readable medium such as on any memory device or in any transmitting device, that are to be executed by a processor.

Examples of memory devices include hard disk drives, diskettes, optical disks, magnetic tape, semiconductor memories such as FLASH, RAM, ROM, PROMS, and the like. Examples of networks include, but are not limited to, the Internet, intranets, telephone/modem-based network communication, hard-wired/cabled communication network, cellular communication, radio wave communication, satellite communication, and other stationary or mobile network systems/communication links. The client device102does not need to be mobile and the first and second access points104and106do not need to provide a wireless connection to the network.

A machine embodying the invention may involve one or more processing systems including, for example. CPU, memory/storage devices, communication links, communication/transmitting devices, servers, I/O devices, or any subcomponents or individual parts of one or more processing systems, including software, firmware, hardware, or any combination or subcombination thereof, which embody the invention as set forth in the claims.

Using the description provided herein, those skilled in the art will be readily able to combine software created as described with appropriate general purpose or special purpose computer hardware to create a computer system and/or computer subcomponents embodying the invention, and to create a computer system and/or computer subcomponents for carrying out the method of the invention.