Patent Publication Number: US-10771556-B2

Title: System and method for sharing unsupported document types between communication devices

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/154,884, filed Oct. 9, 2018, entitled SYSTEM AND METHOD FOR SHARING UNSUPPORTED DOCUMENT TYPES BETWEEN COMMUNICATION DEVICES, which U.S. patent application Ser. No. 16/154,884 is a continuation of U.S. patent application Ser. No. 15/680,702, filed on Aug. 18, 2017, entitled SYSTEM AND METHOD FOR SHARING UNSUPPORTED DOCUMENT TYPES BETWEEN COMMUNICATION DEVICES, now U.S. Pat. No. 10,097,638, issued on Oct. 9, 2018, which U.S. application Ser. No. 15/680,702 is a continuation of U.S. patent application Ser. No. 15/166,437, filed May 27, 2016, entitled SYSTEM AND METHOD FOR SHARING UNSUPPORTED DOCUMENT TYPES BETWEEN COMMUNICATION DEVICES, now U.S. Pat. No. 9,742,846, issued on Aug. 22, 2017. U.S. patent application Ser. No. 15/166,437 is a continuation of U.S. patent application Ser. No. 14/478,498, filed Sep. 5, 2014, entitled SYSTEM AND METHOD FOR SHARING UNSUPPORTED DOCUMENT TYPES BETWEEN COMMUNICATION DEVICES, now U.S. Pat. No. 9,356,997, issued on May 31, 2016, which is a continuation of U.S. patent application Ser. No. 13/789,020, filed Mar. 7, 2013, entitled SYSTEM AND METHOD FOR SHARING UNSUPPORTED DOCUMENT TYPES BETWEEN COMMUNICATION DEVICES, which is a continuation of U.S. patent application Ser. No. 13/079,665, filed Apr. 4, 2011, entitled SYSTEM AND METHOD FOR SHARING UNSUPPORTED DOCUMENT TYPES BETWEEN COMMUNICATION DEVICES, now U.S. Pat. No. 8,407,314, issued Mar. 26, 2013, the contents of which are incorporated herein in their entirety. 
    
    
     INCORPORATION BY REFERENCE 
     The present application incorporates by reference in their entirety U.S. Pat. No. 7,656,870, filed on Mar. 15, 2005, and entitled SYSTEM AND METHOD FOR PEER-TO-PEER HYBRID COMMUNICATIONS; U.S. Pat. No. 7,570,636, filed on Aug. 30, 2005, and entitled SYSTEM AND METHOD FOR TRAVERSING A NAT DEVICE FOR PEER-TO-PEER HYBRID COMMUNICATIONS; U.S. patent application Ser. No. 12/705,925, filed on Feb. 15, 2010, and entitled SYSTEM AND METHOD FOR STRATEGIC ROUTING IN A PEER-TO-PEER ENVIRONMENT; and U.S. patent application Ser. No. 12/728,024, filed on Mar. 19, 2010, and entitled SYSTEM AND METHOD FOR PROVIDING A VIRTUAL PEER-TO-PEER ENVIRONMENT. 
     BACKGROUND 
     Document sharing between devices typically relies on the ability of a device to open a document using an application that is present on the device. However, the device may not have a suitable application installed or such an application may not be available for that particular device. Accordingly, improvements are needed in sharing documents to address such issues. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which: 
         FIG. 1  is a simplified network diagram of one embodiment of an environment illustrating communication devices and a document server. 
         FIG. 2  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  for sharing a document that cannot be opened by the communication devices. 
         FIG. 3  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  to move to another page. 
         FIG. 4  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  to move to another page. 
         FIG. 5  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  to share and save edits to a page. 
         FIG. 6  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  for processing a document to be shared by a communication device. 
         FIG. 7  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  to share a page between communication devices. 
         FIG. 8  is a sequence diagram illustrating one embodiment of a process that may be executed within the environment of  FIG. 1  to move to another page. 
         FIG. 9  is a flow chart illustrating one embodiment of a method that may be executed by a communication device within the environment of  FIG. 1  to share a document with another communication device. 
         FIG. 10  is a flow chart illustrating one embodiment of a method that may be executed by a communication device within the environment of  FIG. 1  to obtain pages representing a document being shared from another communication device. 
         FIG. 11  is a flow chart illustrating one embodiment of a method that may be executed by a communication device within the environment of  FIG. 1  to edit a page and share the edited page. 
         FIG. 12  is a flow chart illustrating one embodiment of a method that may be executed by a communication device within the environment of  FIG. 1  to receive an edited page from another communication device. 
         FIG. 13  is a simplified network diagram of one embodiment of an environment illustrating devices and a document server. 
         FIG. 14  is a simplified network diagram of one embodiment of a hybrid peer-to-peer system within which the communication devices of  FIGS. 1 or 13  may operate. 
         FIG. 15 a    illustrates one embodiment of an access server architecture that may be used within the system of  FIG. 14 . 
         FIG. 15 b    illustrates one embodiment of an endpoint architecture that may be used by a device within the system of  FIG. 14 . 
         FIG. 15 c    illustrates one embodiment of components within the endpoint architecture of  FIG. 15 b    that may be used for cellular network connectivity. 
         FIG. 16 a    is a sequence diagram illustrating the interaction of various components of  FIG. 15 b    when placing a call. 
         FIG. 16 b    is a sequence diagram illustrating the interaction of various components of  FIG. 15 b    when receiving a call. 
         FIG. 17  is a sequence diagram illustrating an exemplary process by which an endpoint of  FIG. 14  may be authenticated and communicate with another endpoint. 
         FIG. 18  is a simplified diagram of one embodiment of a computer system that may be used in embodiments of the present disclosure as a communication device and/or an endpoint. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is directed to a system and method for document sharing between communication devices. It is understood that the following disclosure provides many different embodiments or examples. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
     Referring to  FIG. 1 , in one embodiment, an environment  100  is illustrated with two communication devices  102  and  104 . Examples of such communication devices include cellular telephones (including smart phones), personal digital assistants (PDAs), netbooks, tablets, laptops, desktops, workstations, and any other computing device that can communicate with another computing device using a wireless and/or wireline communication link. Such communications may be direct (e.g., via a peer-to-peer network, an ad hoc network, or using a direct connection), indirect, such as through a server or other proxy (e.g., in a client-server model), or may use a combination of direct and indirect communications. 
     The communication device  102  includes multiple applications  106   a - 106   c . The applications  106   a - 106   c  provide a user of the communication device  102  with the ability to interact with the communication device  102  in order to perform tasks in such areas as communication (e.g., voice and/or video calls, email, and text messaging), scheduling, games, photography, Internet access, and document viewing and/or manipulation. Document viewing and/or manipulation may be performed on various documents  108   a - 108   c  that are stored on or otherwise accessible to the communication device  102 . 
     In the present example, a particular one of the applications  106   a - 106   c  may be associated with one or more document types of the documents  108   a - 108   c . The term “document” as used herein includes any type of text, image, audio, and/or video file or combination of files, and may include files having multiple document types (e.g., an audio/video file or a text document with inline or linked images). A particular document  108   a - 108   c  generally has a document type associated with that document in the format of “document_name.document_type,” so the document  108   a  may be in the format of document_108a.xyz, where .xyz is one of many different document types. 
     The characteristics of a particular document  108   a - 108   c  are dependent on various parameters of that document type. For example, a text document may have formatting parameters, such as font attributes (e.g., bold, underline, and italics), paragraph attributes, and other attributes. An audio document may have a bit rate, length, and other attributes. A video document may have a resolution, frame rate, and other attributes. A document that combines multiple document types may have parameters that represent the document types and/or may link to another document. Accordingly, each document  108   a - 108   c  may be associated with corresponding information that enables the communication device  102  to use one of the applications  106   a - 106   c  to display, play, view, or otherwise handle that document (all of which are represented herein for purposes of clarity by the term “display” regardless of the document type (e.g., playing an audio file is referred to herein as displaying the audio file)). 
     If a document  108   a - 108   c  is not associated with an application  106   a - 106   c  of the communication device  102 , the document is not accessible to (e.g., cannot be opened by) the user of the communication device  102 . For example, if the document  108   a  has a document type of .xyz (document_108a.xyz) and none of the applications  106   a - 106   c  on the communication device  102  are capable of reading and displaying the document type .xyz, the document  108   a  will not be available to the user even though it is present on the communication device  102 . 
     An application may not be available on the communication device  102  for a number of reasons. One reason is that the application may not be supported on the communication device  102  (e.g., the application may use a proprietary document type and not be available for licensing on a particular operating system used by the communication device  102 ). Another reason is that the communication device  102  may have an operating system that does not provide access to certain functions needed by the application for security or other reasons and so the application may not be able to perform properly on that device even if available. 
     The communication device  104  includes applications  110   a - 110   c  that provide a user of the communication device  104  with the ability to interact with the communication device  104  in order to perform tasks in such areas as communication, scheduling, games, photography, Internet access, and document viewing and/or manipulation. Some or all of the applications  106   a - 106   c  and  110   a - 110   c  may be similar or identical. For example, the communication device  102  may include an application  106   a  that is also present in the applications  110   a - 110   c  of the communication device  104 . In other embodiments, the communication devices  102  and  104  may perform a similar or identical function with a different application. For example, the communication device  102  may open an image document having a particular document type (e.g., a GIF file) with a particular application  106   b , and the communication device  104  may open the same image document with another application  110   c . The communication device  104  may also store or access a plurality of documents  112   a - 112   c , each of which may have a document type that is associated with one or more of the applications  110   a - 110   c  as described with respect to the communication device  102 . 
     In the present example, the user of the communication device  102  wants to share the document  108   a  with the user of the communication device  104 . However, neither of the communication devices  102  and  104  is able to open the document. More specifically, the communication device  102  does not have an application  106   a - 106   c  capable of opening the document  108   a  of document type .xyz, and the communication device  104  does not have an application  110   a - 110   c  capable of opening the document  108   a . For purposes of example, the term “open” means able to read and correctly display the document  108   a  on a display of the communication device, where a display is whatever input/output device is used for the document type (e.g., a display may be visual display such as a screen and/or an audio display such as speakers or a headset). 
     It is understood that the communication device  102  may send the document  108   a  to the communication device  104  even though one or both of the communication devices  102  and  104  cannot open the document  108   a , but the sharing of the present example is a collaborative sharing where both users want to open the document  108   a . For example, the users of the communication devices  102  and  104  may want to view the document  108   a  while discussing it and/or may want to edit the document. Sharing of the communication device  102  or  104  itself (e.g., giving control of the communication device to the other communication device) may not be possible and, even if possible, may not be desirable due to security concerns. For example, it may be undesirable to allow the communication device  104  to access the file system of the communication device  102  just to share a document, as any document on the communication device  102  may then be viewed by the communication device  104 . 
     The environment  100  further includes a document server  114  that is coupled to the communication devices  102  and  104  via a network  120 . The document server  114  includes applications  116   a - 116   c  that provide the document server  114  with functionality for managing connections (including communicating with the communication devices  102  and  104 ) and processing documents (as will be described below). In some embodiments, the document server  114  may also include one or more applications for storing documents and/or pages  118   a - 118   c , either on the document server  114  or in another network accessible storage location (not shown). The documents/pages  118   a - 118   c  may be active (currently in use) or archived (stored and not currently in use). 
     The network  120  may be a single network or may represent multiple networks, including networks of different types. For example, the communication device  102  may be coupled to the document server  114  via a network that includes a cellular link coupled to a data packet network, and the communication device  104  may be coupled to the document server  114  via a data packet link such as a wide local area network (WLAN) coupled to a data packet network. Accordingly, many different network types and configurations may be used to couple the communication devices  102  and  104  to one another and to the document server  114 . 
     Exemplary network, system, and connection types include the internet, WiMax, local area networks (LANs) (e.g., IEEE 802.11a and 802.11g wi-fi networks), digital audio broadcasting systems (e.g., HD Radio, T-DMB and ISDB-TSB), terrestrial digital television systems (e.g., DVB-T, DVB-H, T-DMB and ISDB-T), WiMax wireless metropolitan area networks (MANs) (e.g., IEEE 802.16 networks), Mobile Broadband Wireless Access (MBWA) networks (e.g., IEEE 802.20 networks), Ultra Mobile Broadband (UMB) systems, Flash-OFDM cellular systems, and Ultra wideband (UWB) systems. Furthermore, the present disclosure may be used with communications systems such as Global System for Mobile communications (GSM) and/or code division multiple access (CDMA) communications systems. Connections to such networks may be wireless or may use a line (e.g., digital subscriber lines (DSL), cable lines, and fiber optic lines). 
     Communication among the communication device  102 , communication device  104 , and document server  114  may be accomplished using predefined and publicly available (i.e., non-proprietary) communication standards or protocols (e.g., those defined by the Internet Engineering Task Force (IETF) or the International Telecommunications Union-Telecommunications Standard Sector (ITU-T)), and/or proprietary protocols. For example, signaling communications (e.g., session setup, management, and teardown) may use a protocol such as the Session Initiation Protocol (SIP), while data traffic may be communicated using a protocol such as the Real-time Transport Protocol (RTP), File Transfer Protocol (FTP), and/or Hyper-Text Transfer Protocol (HTTP). A sharing session and other communications as described herein may be connection-based (e.g., using a protocol such as the transmission control protocol/internet protocol (TCP/IP)) or connection-less (e.g., using a protocol such as the user datagram protocol (UDP)). While document sharing is occurring, it is understood that other communications may occur, including, but not limited to, voice calls, instant messages, audio and video, emails, and any other type of resource transfer, where a resource represents any digital data. 
     It is understood that the sequence diagrams described herein illustrate various exemplary functions and operations that may occur within various communication environments. It is understood that these diagrams are not exhaustive and that various steps may be excluded from the diagrams to clarify the aspect being described. For example, it is understood that some actions, such as network authentication processes and notifications, may have been performed prior to the first step of a sequence diagram by one or both of the communication devices  102  and  104 . Such actions may depend on the particular type and configuration of each communication device  102  and  104 , including how network access is obtained (e.g., cellular or WLAN access). Other actions may occur between illustrated steps or simultaneously with illustrated steps, including network messaging for call maintenance (including handoffs), communications with other devices (e.g., email, text messages, and/or voice calls (including conference calls)), and similar actions. 
     Referring to  FIG. 2 , a sequence diagram illustrates one embodiment of a message sequence  200  that may occur in the environment of  FIG. 1  to share a document such as the document  108   a  having a document type of .xyz (e.g., document_108a.xyz). Both the communication device  102  and the communication device  104  have applications that can open a document type .abc and a document type .def, but not the document type .xyz. A single application (e.g., the applications  106   a  and  110   a ) may open the document types .abc and .def on a single communication device  102  and  104 , or separate applications may be used for the different document types (e.g., the applications  106   a  and  106   b , and the applications  110   a  and  110   b ). 
     In step  202 , the communication device  102  sends a request for a communication session to the document server  114 . It is understood that the actual format of the request depends on the configuration of the communication device  102  and the document server  114 . In step  204 , the communication device  102  and the document server  114  establish the communication session. In step  206 , the communication device  102  sends the document  108   a .xyz to the document server  114 . The communication device  102  also sends information to the document server  114  about the document_108a.xyz. Some or all of the information may be sent in the request of step  202  or in one or more separate messages. The information may include information about the document_108a.xyz itself and information to be used in converting the document. 
     The information about the document_108a.xyz may include parameters such as document type, number of pages if applicable, and size. The information to be used in converting the document may include a desired document type, a desired resolution, and whether the document is to be only viewable or both viewable and editable. The functional parameters of view only or view/edit may determine which document types are available for conversion. For example, a view only document may be converted to images, while a view/edit document may be converted to a document type that is commonly available. In the present example, the document types available for conversion are generally standards compliant so that viewers/editors are readily available. Furthermore, being standards compliant makes conversion of the document back into the .xyz document type or other documents types more readily available as an option. Being standards compliant may also provide additional portability of the document since more devices may be able to view the document without the need for additional conversions. 
     As stated previously, the communication devices  102  and  104  can both open .abc and .def document types. For purposes of example, .abc and .def are both standards compliant document types and so it is likely that both of the communication devices  102  and  104  either have this functionality or can obtain such functionality (e.g., by downloading an application). 
     The document type into which the document_108a.xyz is to be converted may be selected in various ways. One way is that the communication device  102  can tell the document server  114  what document types are available on the communication device  102 . The document server  114  may then select a document type based on one or more defined criteria, such as which document types are most commonly used. Commonly used may be based on information such as what document types are most commonly requested by the particular communication device  102  or the operating system used by the communication device  102  and similar devices, or as generally requested from the document server  114  by all communication devices. Another way is for the communication device  102  to select a conversion option from the document server  114 . For example, the document server  114  may provide a list of available document types to the communication device  102  (e.g., either based on the document types supported by the communication device  102  or simply a list of all document types supported by the server) and the communication device  102  may inform the document server  114  which document type to use for the conversion. The communication device  102  and document server  114  may communicate to determine what document types are available and then automatically select the conversion document type or provide a list of options (if available) to the user of the communication device  102 . 
     Selection of view only or view/edit may modify the available options. For example, view only may result in the selection of a document type that produces images, while view/edit may result in the selection of a document type that allows easier editing. Examples of view only document types include .gif, .jpg, .png, and similar image document types. Examples of view/edit document types include .txt, .html, .pdf, and other document types that are generally more easily edited than an image file. However, it is understood that overlap between view only and view/edit document types may occur such as when, for example, an image file is edited. 
     In step  208 , the document server  114  converts the document  108   a . In the present example, document_108a.xyz is to be converted into view/edit document type .abc and has multiple pages in its native format of .xyz. The document server  114  converts the document_108a.xyz into multiple pages  118   a - 118   c  of document type .abc. There may not be a one-to-one correspondence between pages of the document_108a.xyz in its native format and the pages  118   a - 118   c  depending on the parameters used in the conversion. For example, if the document_108a.xyz is to be converted into a resolution of 768×1024 for display on the communication devices  102  and  104 , each page  118   a - 118   c  may contain more or less information than a page of the document_108a.xyz. Accordingly, the number of pages  118   a - 118   c  may vary for the same document_108a.xyz depending on the parameters used for conversion. 
     In the present example, the document server  114  stores each page  118   a - 118   c  in an individually accessible manner. For example, each page  118   a - 118   c  may be stored as a separate file on the document server  114  or in another network accessible storage location (not shown) and may be accessed using a path (e.g., a network address ending in the page name). In other embodiments, the pages  118   a - 118   c  may be stored in a single file and accessed by the document server  114  as requested. For example, a request may be received for page  118   b , and the document server  114  may then extract that page from the file and respond to the request. 
     In step  210 , the document server  114  may send one or more updates to the communication device  102 . The update, which may not be sent in some embodiments, may be used to notify the communication device  102  that the conversion process is occurring. Multiple updates may be sent to notify the communication device  102  of the progress of the conversion process. For example, separate updates may be sent to indicate that the conversion process is twenty-five percent complete, fifty percent complete, and seventy-five percent complete. 
     In step  212 , the document server  114  sends access information for one or more of the pages  118   a - 118   c  to the communication device  102 . For example, the document server  114  may send one or more links to the communication device  102  where each link represents a network address that may be used to access the pages  118   a - 118   c . Depending on the configuration of the document server  114  and/or the particular request, the document server  114  may send a single link (e.g., a link to the first page  118   a ), may send multiple links (e.g., a link to each of the pages  118   a - 118   c ), or may send other information (e.g., a link to a single page with information that enables the document server  114  to extract another desired page). In other embodiments, the document server  114  may send a base path and an index or other information that provides the communication device  102  with instructions needed to access each of the pages  118   a - 118   c . For example, the base path may indicate the path to a directory and the index may provide a list of page names or a range of page numbers. The communication device  102  may then append a page name or number to the base path in order to access a particular page. The document server  114  may also send other information to the communication device  102  such as the converted document type (e.g., .abc), the number of pages  118   a - 118   c , the resolution of the pages  118   a - 118   c , and/or a document identifier (ID). 
     In the present embodiment, in step  214 , the communication device  102  and the document server  114  terminate the communication session established in step  204  after the page access information is sent to the communication device  102 . Depending on the configuration of the communication device  102  and document server  114 , the termination may be initiated by either the communication device  102  and/or the document server  114 . In other embodiments, the communication session may remain open for later page transfers. 
     In step  216 , the communication device  102  sends some or all of the page access information to the communication device  104 . For example, if the communication device  102  received an index of pages  118   a - 118   c  from the document server  114 , the communication device  102  may send a link to a single page (e.g., page_118a.abc) to the communication device  104 . Alternatively, the communication device  102  may send a base path and a page identifier (e.g., a name or number) or an index of pages  118   a - 118   b  to the communication device  104 . 
     The communication device  102  may also send additional information, such as an instruction that the communication device  104  retrieve a particular page or simply whatever page is represented by the link (e.g., page_118a.abc). The instruction may be a request that must be approved by the user of the communication device  104  or may be a command that causes the communication device  104  to automatically select the referenced page_118a.abc. The communication device  102  may also send information to the communication device  104  such as a document and/or page prefix (e.g., document_108a and/or page_118a), the number of pages, and a mode type (e.g., view only or view/edit). In step  218 , the communication device  102  requests the page_118a.abc from the document server  114  and, in step  220 , the document server  114  sends the requested page_118a.abc to the communication device  102 . In step  222 , the communication device  104  requests the same page_118a.abc from the document server  114  and, in step  224 , the document server  114  sends the requested page_118a.abc to the communication device  104 . 
     As represented in steps  226  and  228 , respectively, the communication devices  102  and  104  may both display a portion of the document  108   a .xyz as represented by page_118a.abc. As will be described below, the communication devices  102  and  104  may move between the pages  118   a - 118   c , edit the pages  118   a - 118   c , save edited pages, and otherwise view and manipulate the pages  118   a - 118   c  even though neither of the communication devices  102  and  104  can open the original document_108a.xyz. 
     In some embodiments, the document server  114  may provide different document types for each of the communication devices  102  and  104 . For example, if the communication device  102  is able to open documents of document type .abc but not document type .def, and the communication device  104  is able to open documents of document type .def but not document type .abc, the document server  114  may provide pages_118a.abc-page_118c.abc and pages_118a.def-page_118c.def. In such embodiments, the communication device  102  may send the document prefix of document_108a to the communication device  104 , and the communication device  104  may request the appropriate document type from the document server  114 . With information such as the display resolution of the communication devices  102  and  104 , the document server  114  may create pages that contain the same information even though the document types are different. In other embodiments, the communication devices  102  and  104  may compensate based on information from the server. In still other embodiments, the document server  114  may communicate with one or both of the communication devices  102  and  104  and/or the communication devices  102  and  104  may communicate with each other to select page parameters. 
     It is understood that the communication device  102  and  104  may also be coupled via text chat, voice, video with voice, and/or other call types. For example, the users of the communication devices  102  and  104  may be involved in a voice call, and may then share the pages representing the document_108a.xyz for viewing and/or editing while still engaged in the voice call. The users may also audibly relay document locations (e.g., “turn to page 6”), at which time the other user may then instruct the corresponding communication device to select that location. 
     It is understood that variations may exist in the order of steps in the sequence  200 . For example, the communication device  102  may retrieve the page_118a.abc before notifying the communication device  104  to retrieve the page (i.e., step  218  may occur before step  216 ). 
     Referring to  FIG. 3 , a sequence diagram illustrates one embodiment of a message sequence  300  that may occur in the environment of  FIG. 1  to select another page for viewing/editing by the communication devices  102  and  104 . In the present example, the communication device  104  only has address information for the page currently being viewed, but not for pages that have not yet been viewed. 
     In step  302 , the communication device  102  sends access information for another page (e.g., page_118b.abc) to the communication device  104 . The page_118b.abc has not yet been accessed by the communication device  104  and has not been retrieved from the document server  114  by either of the communication devices  102  and  104 . The message of step  302  or a later message (not shown) may include a request that must be approved by the user of the communication device  104  or may be an instruction that causes the communication device  104  to automatically select the referenced page_118b.abc. 
     In step  304 , the communication device  102  requests the page_118b.abc from the document server  114  and, in step  306 , the document server  114  sends the requested page_118b.abc to the communication device  102 . In step  308 , the communication device  104  requests the same page_118b.abc from the document server  114  and, in step  310 , the document server  114  sends the requested page_118b.abc to the communication device  104 . As represented in steps  312  and  314 , respectively, the communication devices  102  and  104  may both display page_118b.abc. 
     It is understood that variations may exist in the order of steps in the sequence  300 . For example, the communication device  102  may retrieve the page_118b.abc before notifying the communication device  104  to retrieve the page (i.e., step  304  may occur before step  302 ). In some embodiments, the sequence  300  may be used for any page other than the currently viewed page. In other embodiments, the sequence  300  may be used for new (not yet viewed) pages and/or pages that are no longer cached if caching is performed. 
     Referring to  FIG. 4 , a sequence diagram illustrates another embodiment of a message sequence  400  that may occur in the environment of  FIG. 1  to select another page for viewing/editing by the communication device  102 . In the present example, the communication devices  102  and  104  store some or all previously viewed pages in memory. For example, the communication devices  102  and  104  may store the previous page or a previous number of pages (e.g., based on page count or an available amount of memory in the communication device). 
     In step  402 , while viewing page_118b.abc, the communication device  102  sends a page identifier for another page (e.g., page_118a.abc) to the communication device  104 . The page_118a.abc has been previously retrieved from the document server  114  by both of the communication devices  102  and  104 . The message of step  402  or a later message (not shown) may include a request that must be approved by the user of the communication device  104  or may be an instruction that causes the communication device  104  to automatically select the referenced page_118a.abc. In steps  404  and  406 , respectively, the communication devices  102  and  104  retrieve page_118a.abc from memory. As represented in steps  408  and  410 , respectively, the communication devices  102  and  104  may both display page_118a.abc. 
     It is understood that the sequences  300  and  400  may be combined depending on whether a page has expired (e.g., is no longer cached for a communication device) or other parameters. For example, one of the communication devices  102  and  104  may retrieve the page from memory while the other communication device retrieves the page from the document server  114 . The page identifier of step  402  may be a similar or identical message to that of step  302  of  FIG. 3 , and the communication device  104  may determine whether the page is cached before retrieving the page. The message sent from the communication device  102  to the communication device  104  may contain a flag or other indicator to notify the communication device  104  that the page has been previously viewed. 
     Referring to  FIG. 5 , a sequence diagram illustrates one embodiment of a message sequence  500  that may occur in the environment of  FIG. 1  when a page is edited. In the present example, both of the communication devices  102  and  104  may edit the page being viewed and the edits may be local only, may be sent to the other device, and/or may be sent to the document server  114 . 
     In step  502 , the communication device  102  edits the current page (e.g., page_118a.abc). For example, if the page_118a.abc is of document type .html or .pdf, the communication device  102  may be used to edit text and attributes of the page_118a.abc, as well as perform markups and other edits. If the page_118a.abc is an image file, the edits are limited to those possible with images. It is understood that the possible edits depend on the document type and the applications available on the communication device  102 . 
     In step  504 , the edited page or page edits may be sent to the communication device  104 . In some embodiments, the entire page with edits may be sent. In other embodiments, only edits may be sent and the communication device  104  may then apply those edits to its local version of page_118a.abc. In step  506 , the communication device  102  may send the edited page or page edits to the document server  114 . The document server  114  may then store the edited page with a user ID to indicate who made the edits. For example, the document server  114  may store the page_118a.abc as page_118a.abc.user 1  and save the revised page separately from the original page_118a.abc. This enables the document server  114  to provide a revision history and to retrieve earlier document versions. As represented in steps  510  and  512 , respectively, the communication devices  102  and  104  may both display the edited page_118a.abc. It is understood that the communication device  104  may also provide an alternate page view to display current local edits made by the communication device  104  but not yet sent to the communication device  102  or document server  114  in some embodiments. 
     In step  514 , the communication device  104  edits the current page (e.g., page_118a.abc) as described with respect to step  502  for the communication device  102 . As with the communication device  102 , the possible edits depend on the document type and the applications available on the communication device  104 . In step  516 , the edited page or page edits may be sent to the communication device  102 . In some embodiments, the entire page with edits may be sent. In other embodiments, only edits may be sent and the communication device  102  may then apply those edits to the page_118a.abc. In step  518 , the communication device  104  may send the edited page or page edits to the document server  114 . The document server  114  may then store the edited page with a user ID to indicate who made the edits. For example, the document server  114  may store the page_118a.abc as page_118a.abc.user 2  and save the revised page separately from the original page_118a.abc. 
     As represented in steps  522  and  524 , respectively, the communication devices  102  and  104  may both display the edited page_118a.abc. It is understood that the communication device  102  may also provide an alternate page view to display current local edits made by the communication device  102  but not yet sent to the communication device  104  or document server  114  in some embodiments. 
     Referring to  FIG. 6 , a sequence diagram illustrates one embodiment of a message sequence  600  that may occur in the environment of  FIG. 1  to process a document (e.g., the document_108a.xyz) to be shared by the communication device  102 .  FIG. 6  illustrates, for example, a more specific embodiment of steps  202 - 214  of  FIG. 2  using SIP for signaling and TCP/IP for document transfer. In some embodiments, the communication devices  102  and  104  in the present example may be endpoints in a peer-to-peer network as described below with respect to  FIG. 14 . 
     In step  602 , the communication device  102  sends a SIP INVITE message to the document server  114  containing document parameters as previously described. For example, the SIP INVITE may contain a request for document conversion (e.g., Content_Type=application/document-conversion, Content_Length=0) and other parameters, such as a desired resolution for converted pages. It is understood that this information need not be in the INVITE message, but may be contained in other SIP signaling messages, such as INFO messages. In step  604 , the document server  114  returns a  100  TRY. In step  606 , the communication device  102  and the document server  114  establish a TCP/IP communication session, which is used in step  608  to transfer the document_108a.xyz from the communication device  102  to the document server  114 . In step  610 , the document server  114  processes the document_108a.xyz into pages (e.g., page_118a.abc-page_108c.abc) as previously described. During step  612 , SIP UPDATE (or INFO) messages may be sent from the document server  114  to the communication device  102  to notify the communication device  102  that the document processing is underway and/or to provide status updates, such a percentage of the processing completed. 
     In step  614 , once the processing in completed, the document server  114  sends a  200  OK to the communication device  102  with the page information as previously described (e.g., path, number of pages, and document type). In step  616 , the communication device  102  responds to the  200  OK of step  614  with an ACK, and the document server  114  sends a BYE to the communication device  102  in step  618 . In step  620 , the communication device  102  and document server  114  may tear down the TCP/IP session. 
     Referring to  FIG. 7 , a sequence diagram illustrates one embodiment of a message sequence  700  that may occur in the environment of  FIG. 1  to share a page (e.g., the page_118a.abc) between the communication device  102  and the communication device  104 .  FIG. 7  illustrates, for example, using SIP signaling to set up a communication session for document sharing between the communication devices  102  and  104  in a more specific embodiment of step  216  of  FIG. 2 , as well as a more specific embodiment of steps  218 - 224  of  FIG. 2  using HTTP for page retrieval. In some embodiments, the communication devices  102  and  104  in the present example may be endpoints in a peer-to-peer network as described below with respect to  FIG. 14 . 
     In step  702 , the communication device  102  sends a SIP INVITE to the communication device  104  to set up a document sharing session. The INVITE contains page parameters to be used for document sharing as previously described. In step  704 , the communication device  104  returns a  100  TRY and, in step  706 , returns a  200  OK to indicate that it is prepared for the document sharing session. In step  708 , the communication device  102  sends an ACK to the communication device  104 . In step  710 , the communication device  102  sends an HTTP GET call to the document server  114  with parameters identifying the page to be retrieved. In step  712 , the document server  114  sends a  200  OK with page_118a.abc to the communication device  102 . In step  714 , the communication device  104  sends an HTTP GET call to the document server  114  with parameters identifying the page to be retrieved. In step  716 , the document server  114  sends a  200  OK with page_118a.abc to the communication device  104 . 
     It is understood that variations may exist in the order of steps in the sequence  700 . For example, the communication device  102  may retrieve the page_118a.abc before notifying the communication device  104  to retrieve the page (e.g., step  710  may occur before step  702 ). 
     Referring to  FIG. 8 , a sequence diagram illustrates one embodiment of a message sequence  800  that may occur in the environment of  FIG. 1  to share a new page between the communication device  102  and the communication device  104 .  FIG. 8  illustrates, for example, a more specific embodiment of steps  302 - 310  of  FIG. 3  using SIP signaling and HTTP for page retrieval. In some embodiments, the communication devices  102  and  104  in the present example may be endpoints in a peer-to-peer network as described below with respect to  FIG. 14 . 
     In step  802 , the communication device  102  sends a SIP INFO (or UPDATE) message to the communication device  104  to indicate that the communication device  104  should display another page (e.g., page_118b.abc). The INFO message contains page parameters to be used for retrieving the new page as previously described. In step  704 , the communication device  104  returns a  200  OK to acknowledge the INFO message. In step  806 , the communication device  102  sends an HTTP GET call to the document server  114  with parameters identifying the new page to be retrieved. In step  808 , the document server  114  sends a  200  OK with the page_118b.abc to the communication device  102 . In step  810 , the communication device  104  sends an HTTP GET call to the document server  114  with parameters identifying the new page to be retrieved. In step  812 , the document server  114  sends a  200  OK with the page_118b.abc to the communication device  104 . 
     It is understood that variations may exist in the order of steps in the sequence  800 . For example, the communication device  102  may retrieve the page_118b.abc before notifying the communication device  104  to retrieve the page (e.g., step  806  may occur before step  802 ). 
     Referring to  FIG. 9 , a flow chart illustrates one embodiment of a method  900  showing how a communication device (e.g., the communication device  102  of  FIG. 1 ) may share a document with another communication device (e.g., the communication device  104  of  FIG. 1 ). The method  900  uses a document server (e.g., the document server  114  of  FIG. 1 ) and a network accessible storage location, which may be the document server  114  in some embodiments. 
     In step  902 , the communication device  102  receives input indicating that a document (e.g., the document_108a.xyz) on the communication device  102  is to be shared with the communication device  104 . In step  904 , a determination is made as to whether the document type of document_108a.xyz is supported by the communication device  102 . If the document type is supported and the document_108a.xyz can be opened by the communication device  102  (e.g., one of the applications  106   a - 106   c  can open the document_108a), the method  900  moves to step  906  and ends. Although not shown, the document_108a may then be handled by the appropriate application  106   a - 106   c . If step  904  determines that the communication device  102  does not have access to an application required for use of the document type .xyz, the method  900  moves to step  908 . 
     In step  908 , the communication device  102  sends the document_108a.xyz and one or more document parameters to the document server  114  for processing as described previously. The document server  114  processes the document_108a.xyz into multiple pages (e.g., page_118a.abc-page_118c.abc) based on the one or more document parameters. Each of the pages is a document type (e.g., document type .abc) that is different from the document type .xyz and is supported by an application present on the communication device  102 . 
     In step  910 , the communication device  102  receives access information for page_118a.abc from the document server  114 , such as a network address that identifies a location of the page on the network accessible storage location. In step  912 , the communication device  102  sends information representing at least one parameter of page_118a.abc and the network address of page_118a.abc to the communication device  104 . Although not shown, it is understood that in some embodiments the communication device  102  may send a request to share the document_108a.xyz and/or the page_118a.abc and the communication device  104  may decline or accept the request. In step  914 , the communication device  102  uses the network address to retrieve page_118a.abc from the network accessible storage location. In step  916 , the communication device  102  displays page_118a.abc on a display that is coupled to or part of the communication device. 
     In step  918 , a determination may be made as to whether another page (e.g., the page_118b.abc) is to be viewed. For example, additional input may be received by the communication device  102 . If the determination indicates that another page is to be viewed, the method  900  returns to step  912 . If the determination indicates that there is not currently another page to view, the method  900  continues displaying the current page and moves to step  920 . In step  920 , a determination may be made as to whether the sharing session is over. If it is, the method  900  moves to step  922  and ends. If the session is to continue, the method  900  returns to step  918 . 
     It is understood that variations may exist in the order of steps in the method  900 . For example, the communication device  102  may retrieve the page_118a.abc before notifying the communication device  104  to retrieve the page (e.g., step  914  may occur before step  912 ). 
     Referring to  FIG. 10 , a flow chart illustrates one embodiment of a method  1000  showing how a communication device (e.g., the communication device  104  of  FIG. 1 ) may obtain pages (e.g., page_118a.abc through page_118c.abc) representing a document (e.g., document_108a.xyz) to be shared from another communication device (e.g., the communication device  102  of  FIG. 1 ). The method  1000  uses a document server (e.g., the document server  114  of  FIG. 1 ) and a network accessible storage location, which may be the document server  114  in some embodiments. 
     In step  1000 , the communication device  104  receives a message from the communication device  102 . The message indicates that the communication device  102  is requesting to share a document with the communication device  104 . Although not shown, it is understood that the communication device  104  may decline or accept the request in some embodiments. In step  1004 , the communication device  104  receives access information for page_118a.abc from the communication device  102  as previously described. The communication device  104  may also receive a notification to get the page identified in the access information from the communication device  102 . 
     In step  1006 , the communication device  104  retrieves page_118a.a from the network accessible storage location and, in step  1008 , displays page_118a.abc on a display that is coupled to or part of the communication device. In step  1010 , a determination may be made as to whether another page (e.g., page_118b.abc) is to be viewed. For example, a determination may be made as to whether another page notification has been received from the communication device  102 . If the determination indicates that another page (e.g., the page_118b.abc) is to be viewed, the method  1000  returns to step  1006 . If the determination indicates that there is not currently another page to view, the method  1000  continues displaying the current page and moves to step  1012 . In step  1012 , a determination may be made as to whether the sharing session is over. If it is, the method  1000  moves to step  1014  and ends. If the session is to continue, the method  1000  returns to step  1010 . 
     Referring to  FIG. 11 , a flow chart illustrates one embodiment of a method  1100  showing how a communication device (e.g., the communication device  102  or  104  of  FIG. 1 ) may edit and share a page (e.g., the page_118a.abc) with another communication device (e.g., the other of the communication devices  102  or  104  of  FIG. 1 ). It is understood that either communication device  102  or  104  may edit page_118a.abc and send the page to the other communication device. The sharing session in the present example does not limit editing to the communication device  102  that is sharing the document, nor does the session limit editing to a device that has control of the session (e.g., there is no “presenter” designation that is needed by a communication device to edit the document), although it is understood that these limitations may exist in some embodiments. Accordingly, while either communication device  102  or  104  can edit the page_118a.abc at any time during the session, the present example uses the communication device  102  as the communication device performing the edits. The method  1100  uses a document server (e.g., the document server  114  of  FIG. 1 ) and a network accessible storage location, which may be the document server  114  in some embodiments. 
     In step  1102 , the communication device  102  receives input to edit the currently displayed page_118a.abc and, in step  1104 , performs and displays the edits. In step  1106 , a determination is made as to whether to send the edited page or edits to the communication device  104 . If not, the method  1100  moves to step  1110 . If the edited page/edits are to be sent, the communication device  102  sends them to the communication device  104  in step  1108  and moves to step  1110 . The sending step  1108  may update the page_118a.abc on the communication device  104  in real time. It is noted that the edited page/edits are not sent through the document server  114  in step  1108  or otherwise retrieved by the communication device  104  from the document server  114 , but are sent from the communication device  102  to the communication device  104 . In step  1110 , a determination is made as to whether to send the edited page or edits to the document server  114  and/or the network accessible storage location. If not, the method  1100  moves to step  1114  and ends. If the edited page/edits are to be sent, the communication device  102  sends them to the document server  114  and/or the network accessible storage location in step  1112  before ending in step  1114 . 
     It is understood that variations may exist in the order of steps in the method  900 . For example, the communication device  102  may send the edited page_118a.abc to the document server  114  before sending it to the communication device  104  (e.g., steps  1110 / 1112  may occur before steps  1106 / 1108 ). 
     Referring to  FIG. 12 , a flow chart illustrates one embodiment of a method  1200  showing how a communication device (e.g., the communication device  102  or  104  of  FIG. 1 ) may receive and display an edited page (e.g., page_118a.abc) from another communication device (e.g., the other of the communication devices  102  or  104  of  FIG. 1 ). It is understood that either communication device  102  or  104  may receive the edited page_118a.abc from the other communication device. Accordingly, while either communication device  102  or  104  can edit the page_118a.abc at any time during the session and send it to the other communication device, the present example uses the communication device  104  as the communication device receiving the edits. In step  1202 , the communication device  104  receives the edited page_118a.abc and, in step  1204 , displays the edited page. 
     Referring to  FIG. 13 , in another embodiment, an environment  1300  is illustrated that may be similar to the environment  100  of  FIG. 1  with the two communication devices  102  and  104  and the document server  114 . In the present example, the document server  114  includes a web interface  1302  and another interface  1304 , which may be any interface that can be used to couple the document server  114  to a networked device. For example, the web interface  1302  may be used to provide access to the documents/pages  118   a - 118   c  to a browser  1310 , such as a web browser on a computing device. The other interface  1304  may be used to provide access to the documents/pages  118   a - 118   c  to a television  1306  or other non-communication device  1308 , which may be any computing device. One example of the other interface  1304  is described in U.S. patent application Ser. No. 12/728,024, filed on Mar. 19, 2010, and entitled SYSTEM AND METHOD FOR PROVIDING A VIRTUAL PEER-TO-PEER ENVIRONMENT, which is hereby incorporated by reference in its entirety. 
     It is understood that the document server  114  may provide various document types of the original document_108a.xyz depending on the device that is requesting access. For example, the document_108a.xyz may be converted to .html pages for the browser  1310 , and may be converted to a suitable television format for the television  1306 . This enables devices other than the communication devices  102  and  104  to view the pages  118   a - 118   c  as viewed by the communication devices. In other embodiments, the other devices may also be able to edit the pages, view edited pages as stored on the document server  114 , and/or save edits to the document server  114 . In still other embodiments, the devices may be able to participate in direct sharing. 
     Referring to  FIG. 14 , one embodiment of a peer-to-peer hybrid system  1400  is illustrated. The system  1400  includes an access server  1402  that is coupled to endpoints  1404  and  1406  via a packet network  1408  that may form part or all of the network  120  of  FIG. 1 . In some embodiments, the endpoints  1404  and  1406  may represent peer-to-peer functionality present on the communication devices  102  and  104  of  FIG. 1 , and so the peer-to-peer architectures and functions described in this embodiment and following embodiments may be used with the preceding embodiments. 
     Communication between the access server  1402 , endpoint  1404 , and endpoint  1406  is accomplished using predefined and publicly available (i.e., non-proprietary) communication standards or protocols (e.g., those defined by the IETF or the ITU-T). For example, signaling communications (e.g., session setup, management, and teardown) may use a protocol such as SIP, while actual data traffic may be communicated using a protocol such as RTP. As will be seen in the following examples, the use of standard protocols for communication enables the endpoints  1404  and  1406  to communicate with any device that uses the same standards. The communications may include, but are not limited to, voice calls, instant messages, audio and video, emails, and any other type of resource transfer, where a resource represents any digital data. In the following description, media traffic is generally based on UDP, while authentication is based on the TCP/IP. However, it is understood that these are used for purposes of example and that other protocols may be used in addition to or instead of UDP and TCP/IP. 
     Connections between the access server  1402 , endpoint  1404 , and endpoint  1406  may include wireline and/or wireless communication channels. In the following description, it is understood that the term “direct” means that there is no endpoint or access server in the communication channel(s) between the endpoints  1404  and  1406 , or between either endpoint and the access server. Accordingly, the access server  1402 , endpoint  1404 , and endpoint  1406  are directly connected even if other devices (e.g., routers, firewalls, and other network elements) are positioned between them. In addition, connections to endpoints, locations, or services may be subscription based, with an endpoint only having access if the endpoint has a current subscription. Furthermore, the following description may use the terms “user” and “endpoint” interchangeably, although it is understood that a user may be using any of a plurality of endpoints. Accordingly, if an endpoint logs in to the network, it is understood that the user is logging in via the endpoint and that the endpoint represents the user on the network using the user&#39;s identity. 
     The access server  1402  stores profile information for a user, a session table to track what users are currently online, and a routing table that matches the address of an endpoint to each online user. The profile information includes a “buddy list” for each user that identifies other users (“buddies”) that have previously agreed to communicate with the user. Online users on the buddy list will show up when a user logs in, and buddies who log in later will directly notify the user that they are online (as described with respect to  FIG. 4 ). The access server  1402  provides the relevant profile information and routing table to each of the endpoints  1404  and  1406  so that the endpoints can communicate directly with one another. Accordingly, in the present embodiment, one function of the access server  1402  is to serve as a storage location for information needed by an endpoint in order to communicate with other endpoints and as a temporary storage location for requests, voicemails, etc., as will be described later in greater detail. 
     With additional reference to  FIG. 15 a   , one embodiment of an architecture  1500  for the access server  1402  of  FIG. 14  is illustrated. The architecture  1500  includes functionality that may be provided by hardware and/or software, and that may be combined into a single hardware platform or distributed among multiple hardware platforms. For purposes of illustration, the access server in the following examples is described as a single device, but it is understood that the term applies equally to any type of environment (including a distributed environment) in which at least a portion of the functionality attributed to the access server is present. 
     In the present example, the architecture includes web services  1502  (e.g., based on functionality provided by XML, SOAP, NET, MONO), web server  1504  (using, for example, Apache or IIS), and database  1506  (using, for example, mySQL or SQLServer) for storing and retrieving routing tables  1508 , profiles  1510 , and one or more session tables  1512 . Functionality for a STUN (Simple Traversal of UDP through NATs (Network Address Translation)) server  1514  is also present in the architecture  1500 . As is known, STUN is a protocol for assisting devices that are behind a NAT firewall or router with their packet routing. The architecture  1500  may also include a redirect server  1516  for handling requests originating outside of the system  1400 . One or both of the STUN server  1514  and redirect server  1516  may be incorporated into the access server  1402  or may be a standalone device. In the present embodiment, both the server  1504  and the redirect server  1516  are coupled to the database  1506 . 
     Referring to  FIG. 15 b   , one embodiment of an architecture  1550  for the endpoint  1404  (which may be similar or identical to the endpoint  1406 ) of  FIG. 14  is illustrated. It is understood that that term “endpoint” may refer to many different devices having some or all of the described functionality, including a computer, a VoIP telephone, a personal digital assistant, a cellular phone, or any other device having an IP stack upon which the needed protocols may be run. The architecture  1550  includes an endpoint engine  1552  positioned between a graphical user interface (GUI)  1554  and an operating system  1556 . The GUI  1554  provides user access to the endpoint engine  1552 , while the operating system  1556  provides underlying functionality, as is known to those of skill in the art. 
     The endpoint engine  1552  may include multiple components and layers that support the functionality required to perform the operations of the endpoint  1404 . For example, the endpoint engine  1552  includes a softswitch  1558 , a management layer  1560 , an encryption/decryption module  1562 , a feature layer  1564 , a protocol layer  1566 , a speech-to-text engine  1568 , a text-to-speech engine  1570 , a language conversion engine  1572 , an out-of-network connectivity module  1574 , a connection from other networks module  1576 , a p-commerce (e.g., peer commerce) engine  1578  that includes a p-commerce agent and a p-commerce broker, and a cellular network interface module  1580 . 
     Each of these components/layers may be further divided into multiple modules. For example, the softswitch  1558  includes a call control module, an instant messaging (IM) control module, a resource control module, a CALEA (Communications Assistance to Law Enforcement Act) agent, a media control module, a peer control module, a signaling agent, a fax control module, and a routing module. 
     The management layer  1560  includes modules for presence (i.e., network presence), peer management (detecting peers and notifying peers of being online), firewall management (navigation and management), media management, resource management, profile management, authentication, roaming, fax management, and media playback/recording management. 
     The encryption/decryption module  1562  provides encryption for outgoing packets and decryption for incoming packets. In the present example, the encryption/decryption module  1562  provides application level encryption at the source, rather than at the network. However, it is understood that the encryption/decryption module  1562  may provide encryption at the network in some embodiments. 
     The feature layer  1564  provides support for various features such as voice, video, IM, data, voicemail, file transfer, file sharing, class 5 features, short message service (SMS), interactive voice response (IVR), faxes, and other resources. The protocol layer  1566  includes protocols supported by the endpoint, including SIP, HTTP, HTTPS, STUN, RTP, SRTP, and ICMP. It is understood that these are examples only, and that fewer or more protocols may be supported. 
     The speech-to-text engine  1568  converts speech received by the endpoint (e.g., via a microphone or network) into text, the text-to-speech engine  1570  converts text received by the endpoint into speech (e.g., for output via a speaker), and the language conversion engine  1572  may be configured to convert inbound or outbound information (text or speech) from one language to another language. The out-of-network connectivity module  1574  may be used to handle connections between the endpoint and external devices (as described with respect to  FIG. 12 ), and the connection from other networks module  1576  handles incoming connection attempts from external devices. The cellular network interface module  1580  may be used to interact with a wireless network. 
     With additional reference to  FIG. 15 c   , the cellular network interface module  1580  is illustrated in greater detail. Although not shown in  FIG. 15 b   , the softswitch  1558  of the endpoint architecture  1550  includes a cellular network interface for communication with the cellular network interface module  1580 . In addition, the cellular network interface module  1580  includes various components such as a call control module, a signaling agent, a media manager, a protocol stack, and a device interface. It is noted that these components may correspond to layers within the endpoint architecture  1550  and may be incorporated directly into the endpoint architecture in some embodiments. 
     Referring again to  FIG. 15 b   , in operation, the softswitch  1558  uses functionality provided by underlying layers to handle connections with other endpoints and the access server  1402 , and to handle services needed by the endpoint  1404 . For example, as is described below in greater detail with respect to  FIGS. 16 a  and 16 b   , incoming and outgoing calls may utilize multiple components within the endpoint architecture  1550 . 
     Referring to  FIG. 16 a   , a sequence diagram  1600  illustrates an exemplary process by which the endpoint  1404  may initiate a call to the endpoint  1406  using various components of the architecture  1550 . Prior to step  1602 , a user (not shown) initiates a call via the GUI  1554 . In step  1602 , the GUI  1554  passes a message to the call control module (of the softswitch  1558 ) to make the call. The call control module contacts the peer control module (softswitch  1558 ) in step  1604 , which detects the peer (if not already done), goes to the routing table (softswitch  1558 ) for the routing information, and performs similar operations. It is understood that not all interactions are illustrated. For example, the peer control module may utilize the peer management module (of the management layer  1560 ) for the peer detection. The call control module then identifies a route for the call in step  1606 , and sends message to the SIP protocol layer (of the protocol layer  1566 ) to make the call in step  1608 . In step  1610 , the outbound message is encrypted (using the encryption/decryption module  1562 ) and the message is sent to the network via the OS  1556  in step  1612 . 
     After the message is sent and prior to receiving a response, the call control module instructs the media control module (softswitch  1558 ) to establish the needed near-end media in step  1614 . The media control module passes the instruction to the media manager (of the management layer  1560 ) in step  1616 , which handles the establishment of the near-end media. 
     With additional reference to  FIG. 16 b   , the message sent by the endpoint  1404  in step  1612  ( FIG. 16 a   ) is received by the endpoint  1406  and passed from the OS to the SIP protocol layer in step  1652 . The message is decrypted in step  1654  and the call is offered to the call control module in step  1656 . The call control module notifies the GUI of an incoming call in step  1658  and the GUI receives input identifying whether the call is accepted or rejected (e.g., by a user) in step  1660 . In the present example, the call is accepted and the GUI passes the acceptance to the call control module in step  1662 . The call control module contacts the peer control module in step  1664 , which identifies a route to the calling endpoint and returns the route to the call control module in step  1666 . In steps  1668  and  1670 , the call control module informs the SIP protocol layer that the call has been accepted and the message is encrypted using the encryption/decryption module. The acceptance message is then sent to the network via the OS in step  1672 . 
     In the present example, after the call control module passes the acceptance message to the SIP protocol layer, other steps may occur to prepare the endpoint  1406  for the call. For example, the call control module instructs the media control module to establish near-end media in step  1674 , and the media control module instructs the media manager to start listening to incoming media in step  1676 . The call control module also instructs the media control module to establish far-end media (step  1678 ), and the media control module instructs the media manager to start transmitting audio in step  1680 . 
     Returning to  FIG. 16 a   , the message sent by the endpoint  1406  (step  1672 ) is received by the OS and passed on to the SIP protocol layer in step  1618  and decrypted in step  1620 . The message (indicating that the call has been accepted) is passed to the call control module in step  1622  and from there to the GUI in step  1624 . The call control module then instructs the media control module to establish far-end media in step  1626 , and the media control module instructs the media manager to start transmitting audio in step  1628 . 
     Referring to  FIG. 17  (and using the endpoint  1404  as an example), a sequence diagram  1700  illustrates an exemplary process by which the endpoint  1404  may authenticate with the access server  1402  and then communicate with the endpoint  1406 . As will be described, after authentication, all communication (both signaling and media traffic) between the endpoints  1404  and  1406  occurs directly without any intervention by the access server  1402 . In the present example, it is understood that neither endpoint is online at the beginning of the sequence, and that the endpoints  1404  and  1406  are “buddies.” As described above, buddies are endpoints that have both previously agreed to communicate with one another. 
     In step  1702 , the endpoint  1404  sends a registration and/or authentication request message to the access server  1402 . If the endpoint  1404  is not registered with the access server  1402 , the access server will receive the registration request (e.g., user ID, password, and email address) and will create a profile for the endpoint (not shown). The user ID and password will then be used to authenticate the endpoint  1404  during later logins. It is understood that the user ID and password may enable the user to authenticate from any endpoint, rather than only the endpoint  1404 . 
     Upon authentication, the access server  1402  updates a session table residing on the server to indicate that the user ID currently associated with the endpoint  1404  is online. The access server  1402  also retrieves a buddy list associated with the user ID currently used by the endpoint  1404  and identifies which of the buddies (if any) are online using the session table. As the endpoint  1406  is currently offline, the buddy list will reflect this status. The access server  1402  then sends the profile information (e.g., the buddy list) and a routing table to the endpoint  1404  in step  1704 . The routing table contains address information for online members of the buddy list. It is understood that steps  1702  and  1704  represent a make and break connection that is broken after the endpoint  1404  receives the profile information and routing table. 
     In steps  1706  and  1708 , the endpoint  1406  and access server  1402  repeat steps  1702  and  1704  as described for the endpoint  1404 . However, because the endpoint  1404  is online when the endpoint  1406  is authenticated, the profile information sent to the endpoint  1406  will reflect the online status of the endpoint  1404  and the routing table will identify how to directly contact it. Accordingly, in step  1710 , the endpoint  1406  sends a message directly to the endpoint  1404  to notify the endpoint  1404  that the endpoint  1406  is now online. This also provides the endpoint  1404  with the address information needed to communicate directly with the endpoint  1406 . In step  1712 , one or more communication sessions may be established directly between the endpoints  1404  and  1406 . 
     Additional details of endpoints and endpoint functionality, including routing and NAT traversal functionality that may be used to establish and maintain a sharing session as described herein, are provided in U.S. Pat. No. 7,656,870, filed on Mar. 15, 2005, and entitled SYSTEM AND METHOD FOR PEER-TO-PEER HYBRID COMMUNICATIONS; U.S. Pat. No. 7,570,636, filed on Aug. 30, 2005, and entitled SYSTEM AND METHOD FOR TRAVERSING A NAT DEVICE FOR PEER-TO-PEER HYBRID COMMUNICATIONS; and U.S. patent application Ser. No. 12/705,925, filed on Feb. 15, 2010, and entitled SYSTEM AND METHOD FOR STRATEGIC ROUTING IN A PEER-TO-PEER ENVIRONMENT, as previously incorporated by reference in their entirety. 
     Referring to  FIG. 18 , one embodiment of a computer system  1800  is illustrated. The computer system  1800  is one possible example of a system component or computing device such as a communication device, a document server, an endpoint, and/or an access server. The computer system  1800  may include a controller (e.g., a central processing unit (“CPU”))  1802 , a memory unit  1804 , an input/output (“I/O”) device  1806 , and a network interface  1808 . The components  1802 ,  1804 ,  1806 , and  1808  are interconnected by a transport system (e.g., a bus)  1810 . A power supply (PS)  1812  may provide power to components of the computer system  1800 , such as the CPU  1802  and memory unit  1804 . It is understood that the computer system  1800  may be differently configured and that each of the listed components may actually represent several different components. For example, the CPU  1802  may actually represent a multi-processor or a distributed processing system; the memory unit  1804  may include different levels of cache memory, main memory, hard disks, and remote storage locations; the I/O device  1806  may include monitors, keyboards, and the like; and the network interface  1808  may include one or more network cards providing one or more wired and/or wireless connections to the network  120  ( FIG. 1 ) and/or the network  1408  ( FIG. 14 ). Therefore, a wide range of flexibility is anticipated in the configuration of the computer system  1800 . 
     The computer system  1800  may use any operating system (or multiple operating systems), including various versions of operating systems provided by Microsoft (such as WINDOWS), Apple (such as Mac OS X), UNIX, and LINUX, and may include operating systems specifically developed for handheld devices, personal computers, and servers depending on the use of the computer system  1800 . The operating system, as well as other instructions (e.g., for the endpoint engine  1552  of  FIG. 15 b    if an endpoint), may be stored in the memory unit  1804  and executed by the processor  1802 . For example, if the computer system  1800  is one of communication devices  102  and  104  or one of the endpoints  1404  and  1406 , the memory unit  1804  may include instructions for performing some or all of the message sequences and methods described with respect to  FIGS. 2-12 and 16   a - 17 . 
     Accordingly, in one embodiment, a method for sharing a document may comprise receiving, by a first communication device, input indicating that a document on the first communication device is to be shared with a second communication device; determining, by the first communication device, that the document is a first document type and that the first communication device does not have access to an application required to display the first document type; sending, by the first communication device, information representing at least one parameter to be used in processing the document to a document server; sending, by the first communication device, the document to the document server for processing into a plurality of pages based on the at least one parameter, wherein each of the plurality of pages is a second document type that is different from the first document type, and wherein the second document type is supported by an application present on the first communication device; receiving, by the first communication device from the document server, access information corresponding to a first page of the plurality of pages, wherein the address information identifies a location of the first page on a network accessible storage location; retrieving, by the first communication device, the first page from the network accessible storage location using the access information; sending, by the first communication device, information representing at least one parameter of the first page and access information for the first page to the second communication device; displaying, by the first communication device, the first page on a display; selecting, by the first communication device, a second page of the plurality of pages; sending, by the first communication device, information requesting the second page to the network accessible storage location; retrieving, by the first communication device, the second page from the network accessible storage location; sending, by the first communication device, information needed to obtain the second page from the network accessible storage location to the second communication device; and displaying, by the first communication device, the second page on the display. The method may further comprise receiving, by the first communication device from the document server, a plurality of network addresses corresponding to the plurality of pages, wherein each of the plurality of network addresses identifies the location of one of the plurality of pages on the network accessible storage location. Sending the information needed to obtain the second page from the network accessible storage location to the second communication device may include sending a network address that corresponds to the second page from the plurality of network addresses. The method may further comprise receiving, by the first communication device from the document server, an index of the plurality of pages, wherein the access information received from the document server includes a base network address of the plurality of pages, and wherein the first communication device is configured to retrieve any of the plurality of pages using the index and the base network address. Sending the information needed to obtain the second page from the network accessible storage location to the second communication device may include sending the base network address and index information corresponding to the second page. Sending, by the first communication device, information needed to obtain the second page from the network accessible storage location to the second communication device may include instructing the second communication device to retrieve the second page. The method may further comprise performing, by the first communication device, an edit to the first page to create a modified first page; and sending, by the first communication device, the edit to the second communication device. Sending the edit may include sending the modified first page. The method may further comprise sending, by the first communication device, the modified first page to the document server. The method may further comprise receiving, by the first communication device, an edit to the first page from the second communication device, wherein the edit creates a modified first page. The information representing at least one parameter to be used in processing the document may include the first document type, a display resolution of the first communication device, and at least one of the second document type and a share mode, wherein the share mode identifies a view only mode or a view/edit mode. The method may further comprise receiving, by the first communication device from the document server, information corresponding to the plurality of pages, wherein the information includes a total number of pages and the second document type. Sending, by the first communication device, information representing at least one parameter of the first page and the access information of the first page to the second communication device may include sending a total number of pages, a page prefix, and at least one of the second document type and a share mode, wherein the share mode identifies a view only mode or a view/edit mode. The method may further comprise receiving, by the first communication device, an update from the document server between the step of sending the document to the document server for processing and the step of receiving the access information by the first communication device from the document server, wherein the update identifies that the processing is in progress. The network accessible storage location may be the document server. Signaling between the first and second communication devices and between the first communication device and the document server may be Session Initiation Protocol signaling. The first and second communication devices may be peer-to-peer devices that communicate directly with each other and the method may further comprise establishing, by the first communication device, a peer-to-peer session with the second communication device prior to sending the information representing at least one parameter of the first page and the access information of the first page to the second communication device. The second communication device may not have access to an application required for use of the first document type and the document may not be able to be opened on the second communication device, and the second document type may be supported by an application present on the second communication device. 
     In another embodiment, a method for sharing a document may comprise receiving, by a first communication device, a message from a second communication device indicating that a document on the second communication device is to be shared with the first communication device, wherein the document is a first document type and the first and second communication devices do not have access to an application required to display the first document type; receiving, by the first communication device from the second communication device, information corresponding to a first page of a plurality of pages that represent the document, wherein each of the plurality of pages is a second document type that is different from the first document type, and wherein the second document type is supported by an application present on the second communication device, and wherein the information includes access information representing a network address corresponding to the first page of the plurality of pages that identifies a location of the first page on a network accessible storage location; retrieving, by the first communication device, the first page from the network accessible storage location using the network address; displaying, by the first communication device, the first page on a display; receiving, by the first communication device from the second communication device, information corresponding to a second page of the plurality of pages; retrieving, by the first communication device, the second page from the network accessible storage location; and displaying, by the first communication device, the second page on the display. The information corresponding to the second page may include a network address of the second page, wherein the first communication device does not know the network address of the second page until it receives the information from the first communication device. The information corresponding to the second page may include an instruction to retrieve the second page. The method may further comprise performing, by the first communication device, an edit to the first page to create a modified first page; and sending, by the first communication device, the edit to the second communication device. Sending the edit may include sending the modified first page. The information corresponding to the first page may include a total number of pages, a page prefix, and at least one of the second document type and a share mode, wherein the share mode identifies a view only mode or a view/edit mode. The first and second communication devices may be peer-to-peer devices that communicate directly with each other and the method may further comprise establishing, by the first communication device, a peer-to-peer session with the second communication device prior to receiving, by the first communication device, the message from the second communication device. 
     In yet another embodiment, a communication device may comprise a network interface configured to send and receive communications via a wireless network; a controller coupled to the network interface; and a memory coupled to the controller, the memory having a plurality of instructions stored thereon for execution by the controller, the instructions including instructions for: receiving input indicating that a document on the first communication device is to be shared with a second communication device; determining that the document is a first document type and that the communication device does not have access to an application required to open the first document type; sending information representing at least one parameter to be used in processing the document to a document server; sending the document to the document server for processing into a plurality of pages based on the at least one parameter, wherein each of the plurality of pages is a second document type that is different from the first document type, and wherein the second document type is supported by an application present on the communication device; receiving access information corresponding to a first page of the plurality of pages from the document server, wherein the address information identifies a location of the first page on a network accessible storage location; retrieving the first page from the network accessible storage location using the access information; sending information representing at least one parameter of the first page and access information for the first page to the second communication device; displaying the first page on a display; receiving input selecting a second page of the plurality of pages; sending information requesting the second page to the network accessible storage location; retrieving the second page from the network accessible storage location; sending information needed to obtain the second page from the network accessible storage location to the second communication device; and displaying the second page on the display. The instructions may further include instructions for establishing a peer-to-peer session with the second communication device prior to sending the information representing at least one parameter of the first page and access information for the first page to the second communication device. The communication device may communicate via the wireless network and the instructions may further comprise instructions for establishing a wireless communication link with the wireless network prior to sending the information representing at least one parameter to be used in processing the document to the document server. The communication device may communicate via the wireline network and the instructions may further comprise instructions for establishing a wireline communication link with the wireline network prior to sending the information representing at least one parameter to be used in processing the document to the document server. 
     While the preceding description shows and describes one or more embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure. For example, various steps illustrated within a particular sequence diagram or flow chart may be combined or further divided. In addition, steps described in one diagram or flow chart may be incorporated into another diagram or flow chart. Furthermore, the described functionality may be provided by hardware and/or software, and may be distributed or combined into a single platform. Additionally, functionality described in a particular example may be achieved in a manner different than that illustrated, but is still encompassed within the present disclosure. Therefore, the claims should be interpreted in a broad manner, consistent with the present disclosure.