Abstract:
A system and method enables Voice over IP (VoIP) session peering via Internet. A converged enterprise web server can receive a request from a caller to initiate a session, associate a Service Level Agreement (SLA) and address information of the caller with the request, and then provide the request to a receiver using a first communication protocol. After accepting from the receiver a response to the request if the caller is an allowed partner of the receiver based on the SLA, wherein the response is associated with address information of the receiver, the converged enterprise web server can establish the session between the caller and the receiver using a second communication protocol.

Description:
COPYRIGHT NOTICE 
     A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 
     FIELD OF INVENTION 
     The invention generally relates to real-time session peering between enterprise Voice over IP (VoIP) networks. 
     BACKGROUND 
     The Session Initiation Protocol (SIP) was initially designed to enable Internet users with personal computers or endpoints to set up real-time sessions that exchange voice, video, and/or data for free. However, the usage of SIP so far has been limited within closed IP networks, such as commercial carrier&#39;s IP Multimedia Subsystem (IMS), or Next Generation Networks (NGN), or enterprise Voice over IP (VoIP) networks. In addition, calls between enterprise SIP-based VoIP networks are infeasible, since a centralized Internet-wide SIP routing scheme is difficult to implement and maintain. 
     SUMMARY 
     In one embodiment, a Web Service, WS-SessionPeering is defined to assist real-time enterprise session peering, while leveraging existing enterprise address resources such as domain name, Hypertext Transfer Protocol (HTTP) Uniform Resource Locators (URLs), emails addresses and/or SIP URLs. Different from previously SIP-enabled end-to-end routing, enterprises can use a Web Service to facilitate the peering handshake prior to session setup. Peering networks can use WS-SessionPeering to facilitate routing, mutual authentication, Service Level Agreement (SLA) control, and exchanging of information necessary for ensuring real-time session establishment. Instead of relying on SIP routing schemes on the Internet, existing enterprise addressing such as enterprise HTTP URL with domain name can be used to reach directly to peer networks. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is an exemplary illustration of VoIP session peering via Internet between two enterprise VoIP networks, in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Closed IP networks use private IP addresses and deploy Network Address Translation/Port Address Translation (NAT/PAT) firewalls. The NAT/PAT firewalls perform private and public IP address mapping for SIP and Real-time Protocol (RTP) so that the session control and media packets traverse cross network boundaries. Almost all of these closed IP networks are isolated topology-hiding private networks. It is difficult to maintain a large global-reachable scheme for SIP routing throughout the whole Internet. In addition, there is no neutral organization that can provide support for all of those telecom carriers and isolated enterprise networks, even though the DNS-based Telephone Number Mapping (ENUM) servers can resolve the E.164 format URLs into domain name or exact IP address. As referred to herein, E.164 format is an international numbering plan for public telephone systems in which each assigned number contains a country code (CC). 
     Telecom carriers establish a limited number of direct network connections with others by deploying dedicated network gateways at the boundary and each has to configure static SIP routing scheme respectively. Hence, the connections among the carriers are limited to a finite number. Also, enterprises VoIP networks have to pay to carriers for making external call through traditional public switched telephone network (PSTN), public land mobile network (PLMN) or NGN/IMS, even though two enterprises each with own VoIP network and high speed Internet access cannot directly peer with each other. 
     Pure SIP-based enterprises VoIP peering needs a centralized third-party routing server to enable an enterprise VoIP SIP server to randomly add and maintain a new SIP route entry to a randomly new partner enterprise. However, such a centralized third-party routing server does not exist, or is difficult to maintain. Furthermore, there are limit resource of static IP addresses, available to support for every possible enterprise VoIP exposure. Also, the enterprise IP address usage tends to change over time and make it difficult for all other peering networks to refresh the routing data in a timely manner. 
     Some enterprises use Internet Service Providers (ISP) such as Skype to save phone cost. However, they have to initiate calls from PCs using a non-E.164 identity, e.g. Skype ID, and the calls to public telephone numbers (possibly in enterprise VoIP network) are charged. The additional ISP IDs adds to the complexity of existing commercial process. Although the non-voice communication means like instant messaging or emails via Internet are adopted for zero cost to assist business, most companies are still relying on public telecom carrier for real-time voice/video communication. 
     Furthermore, peer-to-peer (P2P) technology in SIP does not support non-centralized SIP routing. In addition, to support P2P SIP, the closed enterprise VoIP networks need to publish and open itself to the Internet with static addressing so that they can be contacted by other peers. This brings security concerns to today&#39;s closed-but-safe VoIP networks. Especially, the network is vulnerable to security threats when exposing its static addresses to Internet. 
     In one embodiment, a new Web Service, WS-SessionPeering is defined to assist realtime enterprise session peering, while leveraging existing enterprise address resources such as domain name, HTTP Uniform Resource Locators (URLs), emails addresses and/or SIP URLs. Different from previously SIP-enabled end-to-end routing, enterprises can use a Web Service to facilitate the peering handshake prior to session setup. Peering networks can use WS-SessionPeering to facilitate routing, mutual authentication, Service Level Agreement (SLA) control, and exchanging of information necessary for ensuring real-time session establishment. Instead of relying on SIP routing schemes on the Internet, existing enterprise addressing like enterprise HTTP URL with domain name can be used to reach directly to peer networks. 
     For example, the originating user, or caller, can click-to, or dial, the business identity such as email address of a destination or receiver, instead of having to remember to dial the receiver&#39;s business phone number/extension or the ISP IDs such as Skype. A user&#39;s business email address can be used for session destination, instead of the E.164 phone number, in order to avoid introducing a new addressing scheme. 
     In one embodiment, a Web Service is used to assist VoIP Peering between any enterprise networks while leverage existing enterprise Internet addressing scheme and resources, such as domain name, HTTP URL, and email. There is no need to open static VoIP network addresses (for SIP/RTP) to the Internet. This semi-closed VoIP network exposure approach can dynamically allocate resource upon request. This approach does not rely on carrier&#39;s walled-garden IP networks and telephone numbering schemes, saving cost and making more business sense. In addition, this approach provides easy integration with enterprise service-oriented architecture (SOA) application infrastructure, at the web service layer rather than SIP, and enables close relationship to business partners. 
     In one embodiment, instead of opening static always-on SIP/RTP addresses to public internet, the method employs a secure procedure to open dynamic connections for enterprise VoIP peering. For a new peering session via Internet, the enterprise VoIP NAT/PAT firewall temporarily opens pin-holes for SIP that does session control, and for RTP that bears real-time media packets. Then, the enterprise VoIP NAT/PAT firewall closes the pin-holes right after session ends, thus making these networks semi-closed and more secure. 
     Compared to the Public Switched Telephone Network (PSTN) or carrier VoIP enabled calls, VoIP session peering via Internet is more cost effective. VoIP session peering via Internet can perform authentication and SLA control between peering enterprises, instead of at SIP level. In addition, any enterprise networks via Internet are reachable, there is no need to pre-define SIP routing schemes and static public addresses. VoIP session peering via Internet also provides a cost-effective way of adapting to existing company network, reusing company resources such as web server, VoIP application server, and NAP/PAT firewall. Furthermore, VoIP session peering via Internet can reuse company URL and users email address to do VoIP peering. There is no additional addressing, and no longer heavily relying upon carrier owned E.164 phone numbers and routing schemes. VoIP session peering via Internet provides easy integration into a company SOA infrastructure to facilitate better interoperability between real-time communication applications and enterprise business applications. VoIP session peering via Internet also provides better security by using semi-closed network approach compared to the static network exposure to Internet. VoIP session peering via Internet also provides more flexible and extensible way to separate peering procedure from underlying SIP procedure. In summary, VoIP session peering via Internet provides better support dynamic business partnerships between businesses. 
     In one embodiment, WS-SessionPeering is defined for VoIP peering with public available Web Services Description Language (WSDL) definition, so that all enterprise web servers understand each other using this web service. A default HTTP URL pattern can be defined for accessing the web service, such as http://www.enterpise_domain_name.com/SessionPeering. The enterprise web server, which can support the WS-SessionPeering Web Service and related procedures, may co-exist with the VoIP SIP application server within a converged container. 
     In one embodiment, WS-SessionPeering can be accessed via a public HTTP URL address and interact with enterprise resources. 
       FIG. 1  is an exemplary illustration of VoIP session peering via Internet between two enterprise VoIP networks. As shown in  FIG. 1 , a caller  102  can use WS-SessionPeering to interact with a receiver  112  through peer enterprise Web Server to mutually authenticate each other, enforce Service Level Agreement (SLA) and exchange address information necessary for establishing session peering. The enterprise Web Server  103  or  113  can interact with enterprise directory server (Lightweight Directory Access Protocol (LDAP), exchange, etc.) to resolve the users identity to mapping convert the destined employee&#39;s business address (such as email) to a VoIP phone number, so that the receiver  112  can be reached via VoIP calls. 
     The enterprise Web Server  103  or  113  can instruct the VoIP SIP server  104  or  114  to interact with NAT/PAT firewalls to temporarily open pin-holes for incoming/outgoing peering session upon call setup. Here, a pin-hole describes a port that is opened through a firewall to allow a particular application to gain controlled access to the protected network. For incoming calls routed from the NAT/PAT firewall&#39;s pin-hole allocated, the enterprise Web Server  113  can instruct the VoIP SIP server  114  to temporarily accept it according to SLA; For outgoing call requests accepted by peering Web Server, the enterprise Web Server  103  can instruct the VoIP SIP Server  104  to route call out to peering NAT/PAT firewall&#39;s pin-hole&#39;s public address through own NAT/PAT firewall pin-hole. 
     The SIP Application server can interact with the web server and NAT/PAT firewall for various functions. For example, a SIP Uniform Resource Identifier (URI) parameter can be defined as
         sip:employe_id@enterpirse_domain.com?peer.       

     If a different HTTP URL for accessing the WS-SessionPeering is used (e.g. hosted VoIP), it can appear as a parameter in SIP URI:
         sip:employe_id@enterprise_domain.com?peer;url=http://hosting_domain_name/SessionPeering       

     The SIP Application Server recognizes the session peering request available in above SIP URI and then initiate request to the Web Server for peering request, instead of applying normal routing to carrier&#39;s network. 
     In an example scenario, as shown in  FIG. 1 , Henry at A company (henry@A.com) got to know Bob at B company (bob@B.com) via a business project, where they exchanged name cards. Henry&#39;s telephone address not only has regular E.164 phone numbers, but also his public VoIP phone address that is peering callable: sip:henry@A.com?peer. Bob also has a public VoIP phone address that is peering callable: sip:bob@B.com?peer. 
     The following is an exemplary peering procedure, in accordance with one embodiment of the present invention.
         The caller  102 , Bob, would like to contact with the receiver  112 , Henry, so he inputs sip:henry@hp.com?peer on his SIP desk phone and pressed the dial button.   B company&#39;s SIP VoIP application server  104 , which can be a part of a B company&#39;s converged VoIP Application Server  101 , recognizes this is a VoIP peering call, so it directly the NAT/Pat firewall to open pin-holes for Internet connection.   B company&#39;s SIP VoIP application server  104  reports the pin-hole addresses and receiving address sip:henry@A.com?peer to the Web Server at http://www.B.com/SessionPeering and requests to make a Internet peering call.   B company&#39;s Session Peering Web Server  103  contacts A company&#39;s Session Peering Web Server at http://www.hp.com/SessionPeering via sending WS-SessionPeering request with above information provided.   A company&#39;s Web Server  113  does SLA check to see whether B company is an allowed partner according to provisioned company SLA policy. If yes, it directs the request to A company&#39;s VoIP SIP application server  114 .   A company&#39;s SIP Application server  114  instructs the NAT/PAT firewall to allocate temporary pin-holes for public access to Internet and report to Web Server.   A company&#39;s Web Server  113  responds to B company&#39;s Web Server  103  with own pin-hole public address information.   B company&#39;s Web Server  103  asks the SIP application to route the call to A company&#39;s destination NAT/PAT server&#39;s public address, through B company&#39;s NAT/PAT Server&#39;s pin-holes.   A company&#39;s SIP server  114  recognizes the incoming call and resolves the email address, mapping it to Henry&#39;s desk SIP phone.   Henry&#39;s desktop phone rings and Henry answers the call.   Upon end of the call, the NAT/PAT firewall closes the pin-hole and SIP server notifies Web Server of session ending in both networks.   According to the information collected, each Web Server may record something like “B company Bob calls A company Henry at 10:30 AM for 5:50” for necessary business tracking needs.       

     In one embodiment, the address with peering indication can actually be exchanged in electronic format, such as a .vcf format (a file format standard for electronic business cards), and can be click-to-dialed directly. In the above example, the SIP URI can also be clicked on the webpage or Outlook address book, if the enterprise VoIP solution supports click-to-dial. The Web Server and SIP application server can be integrated on converged VoIP Server. In addition, internal interfaces, such as the interface between SIP and Web Server, and the interface between SIP Server and NAT/PAT firewall, can be defined to assist the VoIP session peering via Internet. 
     The present invention may be conveniently implemented using a conventional general purpose or a specialized digital computer or microprocessor programmed according to the teachings of the present disclosure. Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software art. 
     In some embodiments, the present invention includes a computer program product which is a storage medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the present invention. The storage medium can include, but is not limited to, any type of disk including floppy disks, optical discs, DVD, CD-ROMs, microdrive, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data. 
     The foregoing description of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art. The code examples given are presented for purposes of illustration. It will be evident that the techniques described herein may be applied using other code languages, and with different code. 
     The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalence.