Abstract:
Techniques are provided for leveraging narrowband connectivity (such as dial-up communications or other types of low bandwidth communications) to provision or configure broadband connectivity between a broadband access provider and a broadband device, such as a DSL modem or a cable modem. Specifically, because narrowband connectivity does not require advance configuration or provisioning by the host system of connectivity parameters for an access-seeking device, a modem at an access-seeking device may be leveraged to establish a narrowband connection between that device and a host system and to enable an exchange or negotiation of connectivity parameters necessary to enable future broadband connectivity. Thus, once established, the narrowband connection may be used as a conduit for communicating required provisioning information between the broadband-enabling host and the access-seeking device to enable broadband connectivity by the device in the future.

Description:
TECHNICAL FIELD 
       [0001]    This description relates to communicating between two systems. 
       BACKGROUND 
       [0002]    When two systems communicate, the systems may experience an unintended interruption of the communications session. To continue communications when faced with such an interruption, one system must initiate communications to reestablish the communications session. In fact, where one of the systems or the communication channel there between is secured, an interruption generally requires the system seeking access to resubmit authentication information before communications can be reestablished. Such interruptions often disrupt applications on one of the systems. 
       SUMMARY 
       [0003]    In one general aspect, enabling communications between a user system and an accessible system involves detecting a communications failure in a communications session between a user system and an accessible system. The communications session leverages a first connectivity type. A second communications session between the user system and the accessible system is established in which the second communications session leverages a second connectivity type that differs from the first connectivity type. The second communications session is established automatically in response to the detected communication failure on the session leveraging the first connectivity type. 
         [0004]    Implementations may include one or more of the following features. For example, the second communications session leveraging the second connectivity type may be established without requiring user manipulation. The first connectivity type may be broadband connectivity, the second connectivity type may be narrowband connectivity. 
         [0005]    Using the second communications session leveraging the second connectivity type to receive connectivity information regarding the detected communications failure, status or problem of the first connectivity type, status or problem of the user system, and status or problem of the accessible system and status or problem of a communication pathway between the user system and the accessible system leveraging the first connectivity type. 
         [0006]    The accessible system may be a secure system. When the accessible system is a secure system, the receipt of authentication information from the user system may be enabled. A token may be used to transparently establish the second communications session leveraging the second connectivity type such that at least one of the applications making use of the first communications session is unaffected by the interruption of the first communications session and the establishment of the second communications session. 
         [0007]    The availability of the first connectivity type for communications between the user system and the accessible system may be detected. A third communications session between the user system and the accessible system may be established in which the third communication session leverages the first connectivity type. The first connectivity type may be leveraged automatically in response to the detected availability of the first connectivity type. A token may be used to transparently establish the third communications session leveraging the first connectivity type such that at least one of the applications making use of the second communications session is unaffected by the interruption of the second communications session and the establishment of the third communications session. 
         [0008]    In another general aspect, enabling communications between a user system and an accessible system involves using a communications session of a first connectivity type between the user system and the accessible system. A second connectivity type is leveraged to enable communication of connectivity information to the accessible system regarding the first connectivity type. 
         [0009]    Implementations may include one or more of the features noted above and one or more of the following features. The communications session may be established automatically in response to a detected communication failure of another communications session leveraging the first connectivity type. 
         [0010]    Implementations of any of the techniques discussed above may include a method or process, an apparatus or system, or computer software on a computer-accessible medium. 
         [0011]    The details of one or more implementations set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0012]      FIGS. 1-3  are block diagrams illustrating exemplary communications systems capable of switching between a broadband connection and a narrowband connection. 
           [0013]      FIG. 4  is a block diagram depicting exemplary communications between a client system and a host system to switch between a broadband connection and a narrowband connection in the event of an interruption in the broadband connection. 
           [0014]      FIGS. 5A and 5B  are block diagrams illustrating exemplary communications between a client system and a host system to provide transparent switching between a broadband connection and a narrowband connection to provide uninterrupted access to the host system. 
           [0015]      FIG. 6  is a block diagram showing a communications system capable of reporting, without user intervention, a problem with a broadband connection. 
       
    
    
       [0016]    For brevity, several elements in the figures are represented as monolithic entities. However, as would be understood by one skilled in the art, these elements each may include numerous interconnected computers and components designed to perform a set of specified operations and/or dedicated to a particular geographical region. 
       DETAILED DESCRIPTION 
       [0017]    In the event of an unintentional interruption in communications using a broadband connection between a host system and a client system, a narrowband connection may be established and used until the broadband connection is reestablished. Once the broadband connection is reestablished, communications may use the broadband connection and the narrowband connection may be disconnected. 
         [0018]      FIG. 1  shows a communications system  100  that includes a client system  105  having a home-networking gateway  110  and multiple home-networked devices  115  (“devices”) connected to each other and to the home-networking gateway  110 . The communications system  100  enables the devices  115  to communicate with the host system  120  using the broadband communications device  130  or the narrowband communications device  135  of the home-networking gateway  110 . 
         [0019]    The devices  115 , the home-networking gateway  110 , and the communications devices  130  and  135  of client system  105  may be physically located in a personal residence (e.g., a single-family dwelling, a house, a townhouse, an apartment, or a condominium). However, the location of the home-networking gateway  110  in the personal residence does not necessarily preclude one or more of the devices  115  from being networked to the home-networking gateway  110  from a remote location. Similarly, the location of the home-networking gateway  110  in the personal residence does not necessarily preclude use of one or more of the devices  115  from outside of the personal residence or communication by those devices with the host system  120  through the home-networking gateway  110 . For instance, the devices  115  may include one or more portable computing devices that may be taken outside of the personal residence and still remain connected through a wireless access point to the home-networking gateway  110  located within the personal residence. 
         [0020]    The home-networking gateway  110  is located logically between the devices  115  and a host system  120  that is external to the client system  105 . The host system  120  may be, for example, an Internet access provider device, an Internet service provider device, an online system proxy server, or another external system device. 
         [0021]    The devices  115  may include one or more general-purpose computers (e.g., personal computers), one or more special-purpose computers (e.g., devices specifically programmed to communicate with the home-networking gateway  110  and/or the host system  120 ), or a combination of one or more general-purpose computers and one or more special-purpose computers. Other examples of devices  115  include a workstation, a server, an appliance (e.g., a refrigerator, a microwave, and an oven), an intelligent household device (e.g., a thermostat, a security system, a heating, ventilation and air conditioning (HVAC) system, and a stereo system), a device, a component, other physical or virtual equipment, or some combination of these elements capable of responding to and executing instructions within the system architecture. 
         [0022]    As illustrated by  FIG. 1 , examples of devices  115  may include, but are not limited to, a personal computer with a Windows™ OS  115   a , a Macintosh™ personal computer  115   b , a TV set-top box  115   c , a game device  115   d , a home appliance  115   e , a laptop or otherwise portable computer  115   f , a personal digital assistant (PDA)  115   g , and a wireless access point (WAP)  115   h . Some of the devices, such as a personal computer with Windows™ OS  115   a , a Macintosh™ personal computer  115   b , a TV set-top box  115   c , a game device  115   d , and a home appliance  115   e , typically communicate with the home-networking gateway  110  through a wired network. 
         [0023]    Some of the other devices, such as a laptop computer  115   f  and a PDA  115   g , typically communicate with the home-networking gateway  110  using a wireless access point  115   h . When a device communicates using wireless access point  115   h , the device may be referred to as a wireless device. Wireless devices may include, but may not be limited to portable devices. For example, a desktop personal computer, such as a personal computer with a Windows™ OS  115   a  or a Macintosh™ personal computer  115   b , may communicate using wireless access point  115   h . Typically, the wireless access point  115   h  is connected to home-networking gateway  110  through the wired network, such that the wireless access point  115   h  transmits to the home-networking gateway  110  communications received over a wireless communications pathway from wireless devices. 
         [0024]    A wireless communications pathway may use various protocols to communicate from a wireless device to a wireless access point  115   h . For example, the wireless communications pathway may use wireless technology based on the Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11 standard (such as 802.11b or 802.11a). The wireless communications pathway also may use wireless technology based on the Bluetooth approach for short range wireless communications, other personal area network (PAN) technologies, or other wireless technology, such as the HiperLan2 standard by the European Telecommunications Standards Institute (ETSI). 
         [0025]    Some of the devices  115 , such as personal computer with Windows™ OS  115   a , Macintosh™ personal computer  115   b , laptop computer  115   f , and PDA  115   g , include software for logging on to the host system  120  using a particular client application that is associated with, or that identifies, the user of the device. Such devices may be referred to as client devices. Other devices, such as home appliance  115   e , may include software for logging on to host system  120  without identifying an associated user of the device. Yet other devices, such as TV set-top  115   c  and game device  115   d , may be configured to function either as a client device or a non-client device depending on the function being performed. 
         [0026]    The home-networking gateway  110  may include a home gateway device, such as a gateway, a router, or another communication device. The home-networking gateway  110  also may include a digital hub capable of receiving broadcast video signals, receiving communication data (such as through a broadband connection), and distributing the signals and data to devices  115 . The home-networking gateway  110  may include another communications device and/or a home entertainment device, such as a stereo system, a radio tuner, a TV tuner, a portable music player, a personal video recorder, and a gaming device. 
         [0027]    The home-networking gateway  110  may communicate with the host system  120  over broadband communications links  140 . The home-networking gateway  110  typically connects to the host system  120  using a broadband communications device  130 . Examples of the broadband communications device  130  may include (and are not limited to) a cable modem  130   a  and a DSL modem  130   b . The broadband communications links  140  may include various types of communication delivery systems that correspond to the type of broadband communications device  130  being used. For example, if the home-networking gateway  110  includes a cable modem  130   a  to communicate with the host system  120 , the cable modem  130   a  typically uses the CMTS  140   a  to deliver and receive communications from the host system  120 . In contrast, the DSL modem  130   b  typically delivers and receives communications with the host system  120  through a Digital Subscriber Line Access Multiplexer (DSLAM)  140   b  and an Asynchronous Transfer Mode (ATM) network  140   c.    
         [0028]    The home-networking gateway also may communicate with host system  120  using a narrowband communications device  135 . Examples of the narrowband communications device  135  may include (and are not limited to) an analog modem  135   a  and a satellite modem  135   b . The home-networking gateway  110  uses the narrowband communications device  135  to communicate with the host system  120  through narrowband communications links  180 . The narrowband communications links  180  may include various types of communication delivery systems that correspond to the type of narrowband communications device  135  being used. For example, the analog modem  135   a  may use the Public Switched Telephone Network (PSTN)  180   a  (which also may be referred to as the Plain Old Telephone Service or POTS). When the home-networking gateway  110  includes a satellite modem  135   b , then the communications from a device  115  and an associated home-networking gateway  110  may be delivered to the host system  120  using a satellite dish  180   b  and a satellite  180   c.    
         [0029]    The communications system  100  may use various protocols to communicate between the devices  115  and the home-networking gateway  110  and between the home-networking gateway  110  and the host system  120 . For example, a first protocol may be used to communicate between the devices  115  and the home-networking gateway  110 , and a second protocol may be used to communicate between the home-networking gateway  110  and the host system  120 , where the first protocol and the second protocol may be the same or different protocols. As such, the home-networking gateway  110  may include different hardware and/or software modules to implement different home networking system protocols. 
         [0030]    The home-networking gateway  110  may include broadband configuration information  110   a  that may include information for establishing and/or using a broadband connection to communicate with the host system  120 . Broadband configuration information may include a media access control (MAC) address for the broadband communications device  130 ; a user account, a password, a realm string or another type of identifying information for the broadband account; and a network address (such as an Internet Protocol (IP) address) used to establish a broadband connection between the home-networking gateway  110  and the host system  120 . The broadband configuration information  110   a  may be stored in a table or a list on the home-networking gateway  110 . 
         [0031]    The home-networking gateway  120  also may store narrowband configuration information  110   b . The narrowband configuration information  110   b  may include connectivity parameters (such as a username and password), one or more access telephone numbers, and other information to establish a narrowband connection with the host system  120 . The home-networking gateway configuration information  110   b  may be stored in a table or a list on the home-networking gateway  110 . 
         [0032]    The home-networking gateway  110  also may store home-networking gateway configuration information  110   c  that may include identifying information associated with the home-networking gateway  110 , such as a MAC address. The home-networking gateway configuration information  110   c  also may include device information associated with each device, such as one of devices  115 , that may connect to the home-networking gateway  110 . The device information may include a device identifier for the device, such as its MAC address, a network address (such as a static IP address associated with the device or a dynamic IP address), or other type of hardware device identifier. The dynamic IP address may be assigned to a device by the home-networking gateway  110  or by some other network device through the Dynamic Host Configuration Protocol (DHCP) or another protocol that enables the dynamic allocation of an IP address to a device on a network. 
         [0033]    The device information associated with each device also may include, for example, the type of device (e.g., a client or a non-client device), the class of device (e.g., a gaming device, a personal computer, or a PDA), the type of platform (e.g., the type of hardware, such as a Macintosh™ personal computer, a Windows™-based personal computer, a PDA, a home appliance, or an entertainment device), and/or the operating environment (e.g., the operating system type and/or version). 
         [0034]    In addition, the device information may include a user-assigned name. The user-assigned name may be referred to as a familiar name or a nickname. For example, an identifier for a particular game device may be associated with the user-assigned name of “Billy&#39;s game device.” The device information also may include parental control information or other types of access restrictions that are associated with the device. 
         [0035]    The home-networking gateway configuration information  110   c  may include protocol information necessary to configure the home-networking gateway  110  to communicate with devices  115 , such as information describing how to establish communications with one or more of devices  115 , how to configure the wireless access point  115   h , or how to configure wireless devices, such as the laptop computer  115   h  or the PDA  115   g  using the wireless configuration information. Wireless configuration information may include a security key, such as a wired equivalent privacy (WEP) key that may be used to encrypt and decrypt transmitted data, and a wireless network name, such as a service set identifier (SSID) that identifies the particular network. The wireless configuration information may include other configuration information, such as a level of encryption (e.g., 40-bit encryption or 128-bit encryption) associated with a WEP key. 
         [0036]    The home-networking gateway configuration information  110   c  may include a list of devices that are permitted access to the home network. For example, the home-networking gateway configuration information  110   a  may include a list of MAC addresses that uniquely identify the devices that are permitted access to the home network. 
         [0037]    Additionally or alternatively, the home-networking gateway  110  may communicate with devices using only a wireless communications pathway. In other implementations, the home-networking gateway  110  may communicate with devices using only a wired communications pathway. 
         [0038]    In some implementations the broadband communications device  130  and/or the narrowband communications device  135  may be external to the home-networking gateway  110  in addition to, or in lieu of, the broadband communications device  130  and the narrowband communications device  135  included in the home-networking gateway  110 , as shown in  FIG. 1 . When a communications device is included in the home-networking gateway, the two devices may be said to be “integrated” (e.g., the home-networking gateway may be said to include an integrated communications device). Similarly, in some implementations, a wireless access point  115   h  may be included in the home-networking gateway  110  in lieu of, or in addition to, wireless access point  115   h  that is external to the home-networking gateway  110 , as shown in  FIG. 1 . 
         [0039]    The home-networking gateway  110  may be configured to automatically establish a narrowband connection between the client system  105  and the host system  120  in the event of an unintentional interruption in communications using a broadband connection established between the host system  120  and the client system  105 . The client system  105  may use the narrowband connection for communications with the host system  120  until the broadband connection is available/reestablished. Once broadband access is available, the home-networking gateway  110  may automatically reestablish broadband connectivity for communications between the client system  105  and the host system  120  and may disconnect the narrowband connection with the host system  120 . 
         [0040]    In some implementations, the home-networking gateway  110  may be configured to automatically establish the narrowband connection in the event of an unintended interruption of a broadband connection such that at least one of the applications making use of the broadband communications session is unaffected by the interruption and the reestablishment of the communications session using the narrowband connection. 
         [0041]    In some implementations, the home-networking gateway  110  also may be configured to provide, automatically without user manipulation, information regarding the problem(s) leading or incident to an interruption in the broadband connectivity. The home-networking gateway  110  may send a message to the host system  120  to report the problem with the broadband connection, or the home-networking gateway  110  may connect directly to a problem reporting system of the host system  120  to report the problem. 
         [0042]      FIG. 2  illustrates a communications system  200  including a client system  205  communicating with a host system  220 . In contrast with the communications system  100  of  FIG. 1 , the communications system  200  does not include as part of the client system  205  a home-networking gateway, such as home-networking gateway  110 . 
         [0043]    The host system  220  includes a host device  222  and a host controller  224 . The host device  222  and the host controller  224  each typically include one or more hardware components and/or software components. An example of a host device  222  is a general-purpose computer capable of responding to and executing instructions in a defined manner. Other examples include a special-purpose computer, a workstation, a server, a device, a component, or other physical or virtual equipment or some combination thereof capable of responding to and executing instructions. 
         [0044]    An example of the host controller  224  is a software application loaded on the host device  222  for commanding and directing communications enabled by the host device  222 . Other examples include a program, a piece of code, an instruction, a device, a computer, a computer system, or a combination thereof, for independently or collectively instructing the host device  222  to interact and operate as described. The host controller  224  may be embodied permanently or temporarily in any type of machine, component, physical or virtual equipment, storage medium, or propagated signal capable of providing instructions to the host device  222 . 
         [0045]    The client system  205  communicates with the host system  220  through communications links  230 . The communications link  230  may include or leverage communications pathways  232 ,  234 , enabling communications through the one or more delivery networks  236 . Examples of a delivery network include the Internet, the World Wide Web, WANs, LANs, analog or digital wired and wireless telephone networks (e.g., PSTN (“Public Switched Telephone Network”), ISDN (“Integrated Services Digital Network”), and DSL (“Digital Subscriber Line”) including various forms of DSL such as SDSL (“Single-line Digital Subscriber Line”), ADSL (“Asymmetric Digital Subscriber Loop), HDSL (“High bit-rate Digital Subscriber Line”), and VDSL (“Very high bit-rate Digital Subscriber Line), radio, TV, cable, satellite, and/or any other delivery mechanism for carrying data. Each of the communications pathways  232 ,  234  may include, for example, a wired, wireless, cable or satellite communications pathway. 
         [0046]    The client system  205  typically includes a general purpose computer  270  having an internal or external storage  272  for storing data and programs such as an operating system  274  (e.g., DOS, Windows®, Windows® 95, Windows® 98, Windows® 2000, Windows® NT, Windows® Millennium Edition, Windows® XP, OS/2, Macintosh OS, and Linux) and one or more application programs. Examples of application programs include authoring applications  276  (e.g., word processing, database programs, spreadsheet programs, presentation programs, and graphics programs) capable of generating documents or other electronic content; client applications  278  (e.g., an America Online (AOL) client, CompuServe client, America Online Instant Messaging (AIM) client, AOL TV (“television”) client, and an Internet service provider (ISP) client) capable of communicating with other computer users, accessing various computer resources, and viewing, creating, or otherwise manipulating electronic content; and browser applications  280  (e.g., Netscape&#39;s Navigator and Microsoft&#39;s Internet Explorer) capable of rendering standard Internet content. 
         [0047]    The general-purpose computer  270  also includes a central processing unit  282  (CPU) for executing instructions in response to commands from the client controller  283 . In one implementation, the client controller  225  includes one or more of the application programs installed on the internal or external storage  272  of the general-purpose computer  270 . In another implementation, the client controller  225  includes application programs externally stored in and executed by one or more device(s) external to the general-purpose computer  270 . 
         [0048]    The general-purpose computer typically includes a broadband communications device  284 , such as the cable modem  130   a  or the DSL modem  130   b  of  FIG. 1 , and a narrowband communications device  285 , such as a analog modem  135   a  and a satellite modem  135   b  of  FIG. 1 , for sending and receiving data. Other examples of a communications device  284  or  285  include a transceiver, a set-top box, a communication card, a satellite dish, an antenna, or another network adapter capable of transmitting and receiving data over the communications link  230  through a wired or wireless data pathway  232 . 
         [0049]    The general-purpose computer  270  also may include a TV (“television”) tuner  286  for receiving television programming in the form of broadcast, satellite, and/or cable TV signals. As a result, the client device  220  can selectively and/or simultaneously display network content received by communications device  284  or  285  and television programming content received by the TV tuner  286 . 
         [0050]    The general-purpose computer  270  typically includes an input/output interface  288  to enable a wired or wireless connection to various peripheral devices  290 . Examples of peripheral devices  290  include, but are not limited to, a mouse  291 , a mobile phone  292 , a personal digital assistant  293  (PDA), a keyboard  294 , a display monitor  295  with or without a touch screen input, and/or a TV remote control  296  for receiving information from and rendering information to subscribers. Other examples may include voice recognition and synthesis devices. 
         [0051]    Although  FIG. 2  illustrates devices such as the mobile telephone  292 , the PDA  293 , and the TV remote control  296  as being peripheral with respect to the general-purpose computer  270 , in another implementation, such devices may themselves include the functionality of the general-purpose computer  270  and operate as the client device  220 . For example, the mobile phone  292  or the PDA  293  may include computing and networking capabilities, and may function as a client device  220  by accessing the delivery network  230  and communicating with the host system  220 . Furthermore, the client system  205  may include one, some, all, or none of the components and devices described above. 
         [0052]    The client system  205  may be configured to automatically establish a narrowband connection with the host system  220  in the event of an unintentional interruption in communications using a broadband connection. The client system  205  may use the narrowband connection for communications with the host system  220  until the broadband connection is reestablished. Once broadband access is available, the client system  205  may automatically reestablish broadband connectivity for communications with the host system  220  and may disconnect the narrowband connection with the host system  220 . 
         [0053]    In some implementations, the client system  205  may be configured to automatically establish the narrowband connection in the event of an unintended interruption of a broadband connection such that at least one of the applications making use of the broadband communications session is unaffected by the interruption and the reestablishment of the communications session using the narrowband connection. For example, an application making use of the broadband communications may be unaffected by the interruption and reestablishment when the application is not affected operationally or when it is affected only by the potential of a change in processing speed or responsiveness to user manipulation. In such cases, the application does not fail, become inoperative, or report an error to the user of the application. A user of the application may become aware of a communication speed change that may result from switching from a broadband connectivity type to a slower narrowband connectivity type. The user may experience delay or greater response time in the application even though the user does not experience an application failure or operational error. 
         [0054]    Additionally, the client system  205  also may be configured to automatically report the problem with broadband connectivity. The client system  205  may send a message to the host system  220  to report the problem with the broadband connection or may directly connect to a problem reporting system of the host system  220  to report the problem. 
         [0055]      FIG. 3  shows an implementation of a communications system  300  that includes a client system  305 , a host system  320 , and a communications link  330 . The client system  305  may include one or more of an OS protocol stack  375 , a protocol server module  377 , a controller module  379 , an optional adapter interface  381 , a broadband communications device  384 , and a narrowband communications device  385 . The OS protocol stack  375  may be included as part of an operating system (“OS”). The OS protocol stack  375  may be designed for or capable of enabling the OS to encapsulate data for communication. In general, the OS protocol stack  375  may be implemented using a PPP (“Point-to-Point Protocol”) interface. For example, Windows™ OSs generally include a NDISWAN (“Network Device Interface Specification for Wide Area Networks”) component that functions as the PPP interface. In some Windows™ OSs and in some other types of OSs, a PPP Daemon (PPPD) may function as the PPP interface. 
         [0056]    The protocol server module  377  may be structured and arranged to interface with the client device OS protocol stack  375  and the controller module  379 . The protocol server module  377  enables the client system  310  and the host system  320  to communicate through the delivery network  336  using any one of several encapsulating protocols. 
         [0057]    The protocol server module  377  may intercept and take over a communications session that the OS protocol stack  375  attempts to initiate with the host system  320  using a first protocol. For example, the OS protocol stack  375  may start a communications session intending to negotiate and exchange configuration data with the host system  320  using the first protocol. Instead, the protocol server module  377  may “spoof” the host system  320  and intercept the communications session from the OS protocol stack  375 , rather than having the OS protocol stack  375  communicate directly with the host system  320 . The spoofing typically is transparent to the OS protocol stack  375  and the host system  320 . By capturing the communications session at the protocol server module  377 , the protocol server module  377  may negotiate a separate or a substitute communications session with the host system  320  using a second protocol that is different from the first protocol. Based on this second protocol, data from the OS protocol stack  375  may be routed to the host system  320  over the separate or substitute communications session. Similarly, the protocol server module  377  may be used to spoof the OS protocol stack  375  from the perspective of the host system  320  such that the host system  320  may unknowingly and/or unintentionally transmit to the protocol server module  377  the configuration and/or other data that is destined for the OS protocol stack  375  under the second protocol. The protocol server module  377  then may transport this data to the OS protocol stack  375  using the first protocol. 
         [0058]    Data packets that are destined to be communicated between the OS protocol stack  375  and the host system  320  are translated by the protocol server module  377  between the first protocol and the second protocol. For example, when the data packets include encapsulation, the protocol server module  377  may translate the data packets by removing the encapsulation from the data packets. Additionally or alternatively, the protocol server module  377  may translate the data packets by encapsulating previously unencapsulated data packets or re-encapsulating previously encapsulated data packets using any one of several communications protocols. 
         [0059]    The protocol server module  377  may interface directly with the OS protocol stack  375 , or the client system  305  may further include an interface adapter  381  that the protocol server module  377  uses to interface with the OS protocol stack  375 . For instance, in some OSs in which the OS protocol stack  375  is implemented using a PPPD, the protocol server module  377  may interface directly with the PPPD without the need for an interface adapter  317 . By contrast, in other OSs, such as the Windows™ OS, in which the OS protocol stack  375  is implemented using NDISWAN, the adapter interface  381  may be used to interface the protocol server module  377  and the NDISWAN protocol stack. More specifically, for example, a WAN (“Wide Area Network”) Miniport adapter  381  may be used as a virtual modem to interface the protocol server module  377  and the NDISWAN. 
         [0060]    In one implementation, the protocol server module  377  may include a PPP (“Point-to-Point Protocol”) server module. When the protocol server module  377  functions as a PPP server module, it may capture a PPP communications session between the OS protocol stack  375  and the host system  320 . The PPP server module also negotiates a PPP communications session with the OS protocol stack  375 . The PPP server module may translate PPP data packets from the OS protocol stack  375  destined for the host system  320 . For example, the protocol server module  377  may translate the data packets by removing the PPP encapsulation. The data packets may include data packets in a format consistent with, for example, Internet Protocol (IP) data, Transmission Control Protocol (TCP) data, other data capable of being encapsulated by an encapsulating protocol, or a combination of these data formats. The data packets may include Layer Three data packets. After removing the PPP encapsulation, the PPP server module may encapsulate the packets in any one of several encapsulating protocols (e.g., PPP, UDP (“User Datagram Protocol”), L2TP (“Layer Two Tunneling Protocol”), and PPP over Ethernet (“PPPoE”)). Additionally, the protocol server module  377  may translate data packets from the host system  320  by removing the encapsulation from the data packets and encapsulating the packets in PPP, and then may transport the packets to the client device OS protocol stack  375 . 
         [0061]    The protocol server module  377  may be configured to enable the client system  305  to communicate with the host system  320  using various encapsulating protocols that are supported by the delivery network  336  and the host system  320 , regardless of whether these protocols are otherwise supported by the client system  305 . For instance, although a client system  305  may support only a PPP encapsulating protocol through its OS protocol stack  375 , the protocol server module  377  may function to enable the client system  305  to communicate through the delivery network  336  with the host system  320  using other encapsulating protocols. In a more specific example, the protocol server module  377  generally enables the client system having only a PPP protocol interface to communicate with the host system  320  using, for example, L2TP, PPP, PPPoE, UDP tunneling, token tunneling (e.g., a P3 tunnel), any other encapsulating protocols and tunneling mechanisms, or a combination of these encapsulating protocols and tunneling mechanisms. 
         [0062]    The protocol server module  377  may be implemented as a client application or as a software module within a client application. Examples of client applications include AOL (“America Online”) client, a CompuServe client, an AIM (“America Online Instant Messenger”) client, an AOL TV (“America Online Television”) client, and an ISP (“Internet Service Provider”) client capable of communicating with other computer users, accessing various computer resources, and viewing, creating, or otherwise manipulating electronic content). The encapsulation may be performed by the protocol server module  377 , or alternatively, it may be performed by a separate client application (e.g., PPP client, UDP client, PPPoE client, L2TP client, or AOL client). 
         [0063]    Additionally, the protocol server module  377  may be configured to enable the client system  305  to automatically switch between broadband and narrowband connections in the event of an unintentional interruption in communications using a broadband connection. The protocol server module  377  may be further configured in some implementations to enable the client system  305  to automatically establish the narrowband connection in the event of an unintended interruption of a broadband connection such that at least one of the applications making use of the broadband communications session is unaffected by the interruption and the reestablishment of the communications session using the narrowband connection. Additionally or alternatively, in some implementations, the protocol server module  377  may be configured to enable the client system  305  to automatically report the problem with broadband connectivity. 
         [0064]    The controller module  379  may be logically connected to the protocol server module  377  and may be structured and arranged to control communications between the OS protocol stack  375 , the protocol server module  377 , and the host system  320 . The controller module  379  may be implemented as a client application or as a software module within a client. Additionally, the controller module  379  may function to control the broadband communications device  384  and/or the narrowband communications device  385 . 
         [0065]    The broadband communications device  384  and the narrowband communications device  385  each typically has the attributes of and includes one or more of the communications devices described above with respect to communications devices  130  and  135  of  FIG. 1 . 
         [0066]    The communications link  330  may include communications pathways  332 ,  334  that enable communications through the one or more delivery networks  336 . The delivery network  336  that provides a direct or an indirect communications path between the client system  305  and the host system  320 , irrespective of physical separation. Examples of a delivery network  336  include the Internet, the World Wide Web, WANs, LANs, analog or digital wired and wireless telephone networks (e.g., PSTN (“Public Switched Telephone Network”), ISDN (“Integrated Services Digital Network”), and DSL (“Digital Subscriber Line”) including various forms of DSL such as SDSL (“Single-line Digital Subscriber Line”), ADSL (“Asymmetric Digital Subscriber Loop), HDSL (“High bit-rate Digital Subscriber Line”), and VDSL (“Very high bit-rate Digital Subscriber Line), radio, TV, cable, satellite, and/or any other delivery mechanism for carrying data. Each of the communications pathways  332 ,  334  may include, for example, a wired, wireless, cable or satellite communications pathway. 
         [0067]      FIG. 4  shows an exemplary process  400  between a client system  405  and a host system  420  that automatically switches between a broadband connection and a narrowband connection to provide network access in the event of a disruption of the broadband connection. The client system  405 , for example, may be an implementation of the home-networking gateway  110  or the client system  105  both of  FIG. 1 , the client system  205  of  FIG. 2 , or the protocol server module  377  or client system  305  both of  FIG. 3 . The host system  420 , for example, may be an implementation of the host system  320  of  FIG. 1 , the host system  220  of  FIG. 2 , or the host system  320  of  FIG. 3 . 
         [0068]    The procedure  400  begins when a communications session using a broadband connection is established between the host system  420  and the client system  405  (step  430 ). The establishment of the communications session may include having the host system  420  authenticate the client system  405  and/or and provide a communication address for the broadband connection. 
         [0069]    More specifically, the establishment of the communications session (step  430 ) may be initiated, for example, when the client system  410  submits a request for access to the host system  420 . The host system  420  may request authentication information from the client system  405 , which receives the authentication request and submits the requested authentication information. Authentication information may include a user identifier (such as, for example, a user name, a screen name, or a phone number) and access password (such as, for example, a subscriber password or personal identification number (“PIN”)), which may be used to authenticate the client system as authorized. The host system  420  receives the authentication information and authenticates the client system. 
         [0070]    During the establishment of the communications session (step  430 ), the host system  420  may provide a host-designated communications address to the client system  405 . The host-designated communications address may be, for example, an Internet Protocol address. Alternatively, the communications address may be a port that has been assigned by a Network Address Translator (NAT). The communications address may be a numerical or alphabetical address (such as a domain name). 
         [0071]    When the client system  405  and the host system  420  experience an interruption in the communications session (step  444 ), the client system  405  detects the interruption (step  447   c ). The interruption in the communications session may occur when the communications session fails—that is, the communication session is interrupted due to a disconnection between the client system  405  and the host system  420 . The communications session failure may occur because of a problem with the client system  405 , the host system  420 , or the communication pathway between the client system  405  and the host system  420 . 
         [0072]    When the client system  405  includes a home-networking gateway that includes an integrated broadband communications device, such as home-networking gateway  110  of  FIG. 1  that includes a DSL modem, the client system  405  may detect the interruption of the broadband connection by detecting the loss of the ATM link. When the client system  505  does not include a home-networking gateway with an integrated broadband communications device, the interruption in the broadband connection may be detected by, for example, a failure in an attempt to communicate with the host system  420  or the receipt of a notice of failure from an application running on the client system  405 . The client system  405  also may detect the interruption in the broadband connection when monitoring the broadband connection. For example, the client system  405  may periodically attempt to contact the host system  420  through the broadband connection (e.g., send a ping to the host system  420  and wait for a reply). When a response is not received from the host system  420 , the client system detects an interruption in the broadband connection with the host system  420 . 
         [0073]    Additionally or alternatively, the client system  405  may inform the user of the client system  405  about the interruption, for example, by displaying a message. Informing the user of the client system  405  of the interruption may be beneficial, for example, when the client system dials a modem to reestablish a connection with the host system so that the user is not surprised by the sound of the modem dialing. 
         [0074]    The client system  405  initiates a narrowband connection with the host system  420  and requests narrowband access from the host system (step  455   c ). This may be accomplished, for example, when the client system  405  uses a narrowband communications device to establish a narrowband connection, such as a dial-up connection, with the host system  420 . In some implementations, identification information (such as user name) may be sent to the host system  420  from the client system  405  when the narrowband connection is initiated. In other implementations, identification information may be sent later, as described below with respect to steps  457   h - 460   h.    
         [0075]    The host system  420  receives the request for narrowband access (step  455   h ). The receipt of the request for narrowband access may enable the host system  420  to detect the communications session interruption when the host system  420  has not yet otherwise detected the interruption of the communications session. 
         [0076]    The host system may request authentication information from the client system  405  (step  457   h ), and if so, the client system  405  receives the authentication request (step  457   c ) and submits authentication information using the narrowband connection (step  460   c ). This may be accomplished, for example, by submitting narrowband configuration information stored on the client system, such as narrowband configuration information  110   b  of  FIG. 1 . The host system  420  receives the authentication information (step  460   h ). 
         [0077]    If the host system  420  has not yet otherwise detected the interruption of the communications session, receiving authentication information from a client system  405  may enable the host system  420  to detect the communications session interruption. The steps  457   h - 460   h  may be referred to as sub-process  462 , which may be optionally performed. In some implementations, the request for narrowband access from the client system  405  may include authentication information so as to obviate the need for sub-process  462 . 
         [0078]    The host system  420  authenticates the client system  405  (step  464   h ). 
         [0079]    The client system  405  and the host system  420  exchange communications using the narrowband connection (step  470 ). Optionally, the client system  405  may provide, without user intervention, information regarding the problem(s) leading or incident to an interruption in the broadband connection to the host system  420  (step  474   c ). This may be accomplished, for example, by the client system  405  sending an electronic mail message or other type of communication to the host system  420  to provide the information regarding the broadband connection. For example, the client system  405  may send an electronic mail (“email”) message to a designated email address to report the loss of the broadband connection. The client system  405  may include information about the trouble or about the connection within the email message. For example, the client system  405  may include diagnostic information about the broadband device in the email message. Alternatively or additionally, the client system  405  may report the loss of the broadband connection directly to the host system  420  by connecting to an application program or host service for that purpose (e.g., a trouble-reporting application for technical support or a call center). The client system  405  also may connect directly to a problem reporting system of the host system  420  to provide the information. 
         [0080]    When the broadband connection again becomes available (step  475 ) and the client system  405  detects availability of the broadband connection (step  477   c ), the client system  405  initiates the establishment of communications using the broadband communications (step  490 ) and disconnects the narrowband connection (step  495   c ). The client system  405  may detect the availability of the broadband connection, for example, by periodically trying to establish a broadband connection with the host system. When the client system  405  includes a home-networking gateway with an integrated DSL modem, such as the home-networking gateway  110  depicted in  FIG. 1 , the home-networking gateway may be able to detect the availability of the broadband connection based on the reestablishment of the underlying ATM link. When the client system  405  does not include a home-networking gateway with an integrated broadband communications device, the client system  405  may use an active monitoring process to detect the availability of the broadband connection. One example of an active monitoring process is when the client system  405  periodically tries to contact the host system  420  through the broadband connection (e.g., sends a ping to the host system  420  and waits for a reply). When the client system  405  receives a response from the host system  420 , the client system determines that the broadband connection is available. 
         [0081]      FIGS. 5A and 5B  depict a process  500  to provide transparent reconnection of a communications session between the client system  505  and the host system  520  when the broadband connection is interrupted. The client system  505 , for example, may be an implementation of the home-networking gateway  110  or the client system  105  both of  FIG. 1 , the client system  205  of  FIG. 2 , the protocol server module  377  or client system  305  both of  FIG. 3 , or the client system  410  of  FIG. 4 . The host system  520 , for example, may be an implementation of the host system  120  of  FIG. 1 , the host system  220  of  FIG. 2 , the host system  320  of  FIG. 3 , or the host system  420  of  FIG. 4 . 
         [0082]    The procedure  500  begins when a communications session using a broadband connection is established between the host system  520  and the client system  505 , as described previously with respect to step  430  of  FIG. 4  (step  530 ). 
         [0083]    The client system  505  requests a reconnection token (step  535   c ), which may be used to reestablish communications between the client system  505  and the host system  520  after an unintentional interruption of the communications session. The reconnection token may be valid only for two submissions and may be valid only for a period of time, usually a short period of time, following an interrupted communications session. 
         [0084]    The host system  520  receives the token request (step  535   h ). The host system  520  generates the reconnection token (step  537   h ). The generation of the reconnection token may include relating the reconnection token to the host-designated communications address, storing the reconnection token, the host-designated communication address and the relationship between the reconnection token and address. 
         [0085]    The host system  520  provides the reconnection token to the client system (step  538   h ), which receives (step  538   c ) and stores the token (step  540   c ). 
         [0086]    When the client system  505  and the host system  520  experience an interruption in the communications session (step  545 ), the client system  505  or the host system  520  may detect the interruption (steps  547   c  and  547   h ). However, to enhance security, it may be possible to limit detection of the interruption to the host system, thus reducing the opportunities for spoofing of authentic tokens. 
         [0087]    When the host system  520  detects the interruption based on criteria other than receipt of an access request or token from a disconnected client system (step  547   h ), the host system reserves the communications address used in the interrupted communications session during the period of interruption (step  550   h ). The host system may limit the duration of the reservation for a specific period of time (which may be referred to as the lifespan of the token) that is measured from the time of communications session interruption. This may be accomplished, for example, by having a list or table of issued reconnection tokens and storing the client system to which the reconnection token was issued and the time of interruption, if any, for each issued reconnection token. 
         [0088]    If, during the lifespan of the reconnection token, the host system  520  receives a request for access from the client system  505  without the client system submitting the reconnection token, the host system  520  may take any of several actions, including terminating the session immediately, continuing to wait for the submission of the reconnection token or the expiration of the lifespan of the reconnection token, and providing access using a host-designated communication address that is not the same as the reserved communication address. 
         [0089]    The client system  505  detects an unintentional interruption of the broadband connection, such as described previously with respect to step  447   c  of  FIG. 4  (step  547   c ). The client system  505  initiates a narrowband connection with the host system  520  and requests narrowband access from the host system, such as described previously with respect to step  455   c  of  FIG. 4  (step  555   c ). The host system  520  receives the request for narrowband access (step  555   h ) and requests authentication information from the client system  505  (step  557   h ), such as described previously with respect to steps  455   h  and  457   h  of  FIG. 4 . 
         [0090]    The client system  505  receives the authentication request (step  557   c ) and submits the reconnection token using the narrowband connection with the host system  520  (step  560   c ). More specifically, the client system may determine whether a reconnection token exists, retrieve the reconnection token from storage, and send the reconnection token to the host system. The reconnection token may be submitted automatically in lieu of or in addition to authentication information, unprompted, or in response to a request from the host system. Such a process generally preempts or replaces the display of a user interface soliciting reconnection or reauthentication information from a user. 
         [0091]    Alternatively, the client system  505  may submit the reconnection token when the client system  505  initiates the narrowband connection and requests access to the host system  520 . 
         [0092]    The host system  520  receives the authentication information in the form of the token (step  560   h ). If the host system  520  has not yet otherwise detected the interruption of the communications session, receiving authentication information from a client system  505  using a reconnection token may enable the host system  520  to detect the communications session interruption. 
         [0093]    Referring also to  FIG. 5B , the host system  520  responds to receipt of authentication information by authenticating the client system (step  565   h ), which may involve determining whether the reconnection token submitted by the client system is valid (such as, by comparing the received reconnection token with a list of issued tokens, by looking up the reconnection token in a table that lists all valid reconnection tokens, or, if the reconnection token is time-limited or use-limited, determining whether it is expired). The host system  520  then provides access using the same communications address which was used in the interrupted broadband communications session in order to reestablish communications with the client system  505  (step  567   h ). 
         [0094]    The client system  505  receives reconnection access such that at least one of the client applications making use of the communication session does not experience a disruption despite the communications session interruption; that is, at least one client application is unaffected by the interruption and the associated reconnection, which has been described previously with respect to  FIG. 2  (step  567   c ). Moreover, some operating systems may terminate a client application upon loss of a connection to the host system on which the client application depends. An operating system on the client system  505 , however, may be prevented from terminating a client application by masking the loss of the connection, for instance, using a local protocol module that “spoofs” the operating system protocol stack and host system, as described with respect to  FIG. 3 . 
         [0095]    In some implementations, the client system  505  may receive reconnection access using the same session identifier that was associated with the interrupted session (step  567   c ). 
         [0096]    The client system  505  and the host system  520  exchange communications using the narrowband connection (step  570 ). Optionally, the client system  505  may provide, without user intervention, information regarding the problem(s) leading or incident to an interruption, with the broadband connection to the host system  520 , as described previously with respect to step  474   c  of  FIG. 4 . When the broadband connection again becomes available (step  576 ) and the client system  505  detects availability of the broadband connection (step  577   c ), the client system  505  submits to the host system  520  the reconnection token using the broadband connection (step  580   c ). In some implementations, the host system  520  may detect availability of the broadband connection (step  577   c ) and request from the client system  510  authentication information and/or the reconnection token. In response, the client system  510  submits the reconnection token using the broadband connection (step  580   c ). 
         [0097]    The host system  520  receives authentication information from the client system  505  in the form of the reconnection token (step  580   h ), authenticates the client system  505  (step  585   h ), and provides access using the reserved communication address (step  587   h ). To provide access to the client system  505  using the reserved communication address, the host system  520  may disconnect the narrowband connection with the client system  510  that used the reserved communication address. 
         [0098]    In some implementations, the client system  505  may receive reconnection access using the same session identifier that was associated with the interrupted session. 
         [0099]    The client system  505  receives reconnection access transparent to at least one client application (step  587   c ), as described previously with respect to step  567   c . The client system  505  and the host system  520  exchange communications using the broadband connection (step  590 ). 
         [0100]    In some implementations, a single-use reconnection token may be used. In such a case, when the narrowband connection is established for communications between the host system  520  and the client system  505  (steps  555   c - 570   c ), the client system  505  may request and be provided a second reconnection token from the host system in a manner the same as or similar to that described previously in steps  535   c - 540   c . The client system  505  may use the second reconnection token to transparently connect to the host system using the reestablished broadband connection when the broadband connection becomes available (step  580   c ). 
         [0101]      FIG. 6  illustrates a communications system  600  capable of reporting, without user intervention, a problem with a broadband connection between a client system and a broadband access provider. The communications system  600  includes a client system  605  that has a home-networking gateway  610  and a client device  615 , a host system  620 , and a broadband access provider  650 , and a network  655 . 
         [0102]    The client system  605  may be an implementation of the client system  105  of  FIG. 1 . The home-networking gateway  610  generally maintains a persistent broadband connection to broadband access provider  650 . The broadband persistent connection may be a connection using, for example, a cable modem, such as cable modem  130   a  of  FIG. 1 , or a DSL modem, such as DSL modem  130   b  of  FIG. 1 . 
         [0103]    The broadband access provider  650  provides client system  610  with access to network  655 , which may be an implementation of network  236  of  FIG. 2  or network  336  of  FIG. 3 . The broadband access provider  650  may be a host system similar to the host system  120  of  FIG. 1 , the host system  220  of  FIG. 2 , the host system  320  of  FIG. 3 , the host system  420  of  FIG. 4 , or the host system  520  of  FIGS. 5A and 5B . However, the broadband access provider  650  receives notification of an interruption, or other type of problem, with the broadband connection between the broadband access provider  650  and the client system  605  from the host system  620 . 
         [0104]    When the client system  605  detects an interruption of the broadband connection with the broadband access provider  650 , the client system  605  establishes a transient connection (such as a narrowband or dial-up connection) with the host system  620  using communications link  630 , which may be an implementation of communications links  230  of  FIG. 2 . The communications link  630  may include communications pathways  632  and  634  enabling communications through the one or more delivery networks  636 . 
         [0105]    The client system  605  and the host system  620  may exchange communications that include authentication messages used to establish a trusted connection. The client system  605  notifies the host system  620  of the interruption of the broadband connection with the broadband access provider  650 . For example, the client system  605  may send an email message or other type of communication to the host system  620 . The client system also may connect with a trouble reporting application of the host system  620  to report a problem with the broadband connection. The client system  605  may include diagnostic or other information, for example, obtained from the broadband communications device with the notification. 
         [0106]    The host system  620  notifies the broadband access provider  650  of the problem with the broadband connection. In some implementations, the host system  620  may establish a persistent connection with the broadband access provider  650 , and it may provide that broadband access provider  650  with information needed to rectify the reported problem, which information may or may not be obtained or solicited from the client system  605 . A persistent connection may be particularly beneficial when the number of notifications or other types of communications routed between the broadband access provider  650  and the host system  620  is greater than the capacity afforded by a transient connection that requires authentication to be performed when a connection is established. 
         [0107]    The host system  620  and the broadband access provider  650  may be owned or controlled by the same or different legal entities. Generally, the host system  620  and the broadband access provider  650  are different legal entities. 
         [0108]    Although the techniques have been described using a host system and a client system, the techniques and concepts extend to systems communicating other than in a client and host relationship and therefore are applicable to other contexts. For example, the benefits may be applicable to systems that are accessible by a user system, such as a system in a point-to-point communications system or a trusted computer system that is not necessarily engaged in a host-client relationship with a user system. A system that is accessible by a user system may be referred to as an accessible system. 
         [0109]    Although techniques have been described using a broadband connection and a narrowband connection, the techniques and concepts may be applicable to other types of connections. 
         [0110]    The techniques and concepts are applicable to communications devices other than a gateway or a home-networking gateway. For example, a router, a digital hub, a general-purpose computer, or a single-purpose configuration management device may perform the functions described as being performed by the gateway. The gateway also may be referred to as a local proxy device. 
         [0111]    Implementations may include a method or process, an apparatus or system, or computer software on a computer medium. It will be understood that various modifications may be made that still fall within the following claims. For example, advantageous results still could be achieved if steps of the disclosed techniques were performed in a different order and/or if components in the disclosed systems were combined in a different manner and/or replaced or supplemented by other components.