IA
CROSS-REFERENCE TO RELATED APPLICATION
[0001] n/a
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT
[0002] n/a.
FIELD OF THE INVENTION
[0003] The present invention relates to communication networks, and more particularly to a
method, system and apparatus that provides for contextual control of inter-human
communication.
BACKGROUND OF THE INVENTION
[0004] The traditional public switched telephone network ("PSTN") operates on an
anonymous calling paradigm. The only requirement is the knowledge and use of a phone
number to establish a request (ring) for communications. This means that as long as a caller
knows the telephone number of the receiver, that caller can ring the receiver in an attempt to
establish audio communications with that receiver. There are many benefits to this model that
are well attested by the success of the PSTN today. Next generation Internet Protocol ("IP")
based communications technologies, unlike the PSTN, are developed under an open system
environment rooted in the Internet-centric paradigm. Accordingly, the Internet-centric paradigm
is not anonymous, but instead demands identification and authorization of the caller. Session
Initiation Protocol ("SIP") allows for full session establishment and management but requires a
degree of trust that is not typically available in the enterprise or provider network. SIP is a
proposed standard that may be used to initiate, modify, and terminate an interactive user session
that involves multimedia elements, such as voice (audio), video, instant messaging, online games

and virtual reality. In particular, SIP provides a signaling and call setup protocol for IP-based
communications that can support a superset of the call processing functions and features present
in the PSTN. The SIP protocol by itself does not define these features, but instead, focuses on
call setup and signaling. The SIP protocol does, however, enable the building of the PSTN
features in network elements known as proxy servers and user agents.
[0005] A user agent is the client application used with a particular network protocol; the
phrase is most commonly used in reference to those which access the World Wide Web
("WWW"). Web user agents range from web browsers to search engine crawlers, as well as
mobile phones, screen readers and Braille browsers used by people with disabilities. When
Internet users visit a web site, a text string is generally sent to identify the user agent to the
server. This text string forms part of the hypertext transfer protocol ("HTTP") request, prefixed
with user-agent and typically includes information such as the application name, version, host
operating system, and language. Internet bots, such as web crawlers, often also include a
uniform resource locator ("URL") and/or e-mail address so that the webmaster can contact the
operator of the bot. A bot is a common phrase on the Interact for a software program that is a
software agent. A bot interacts with other network services intended for people as if it were a
person and typically it is used to gather information.
[0006] A proxy server is a computer that offers a computer network service to allow clients
to make indirect network connections to other network services. A client connects to the proxy
server, then requests a connection, file, or other resource available on a different server. The
proxy server provides the resource either by connecting to the specified server or by serving it
from its memory cache.
2

[0007] The SIP protocol acts in concert with several other protocols and is only involved in
the signaling portion of a communication session. SIP acts as a carrier for the session
description protocol ("SDP"), which describes the media content of the session, e.g. what IP
ports to use, the codec being used, the specific media format, etc. In typical use, SIP "sessions"
are packet streams of the Real-time Transport Protocol ("RTP") where RTP is the carrier for the
actual voice or video content itself.
[0008] As multimedia collaborative communications emerge as commonplace, a result of
Internet-centric protocols and mobility technologies, it is desirable to have a system or
mechanism that can provide the function of the anonymous calling capabilities available to the
legacy PSTN circuit switched environment. In addition, there should be a method for filtering
against contextual media types.
[0009] One approach to provide security and to establish inter-domain trust on a session-by-
session basis is defined by the work of the Internet Engineering Task Force ("IETF") on the use
of Certificate Authorities. A Certificate Authority is an entity, which issues digital certificates
for use by other parties, and is an example of a trusted third party. A Certificate Authority will
issue a public key certificate that attests that the public key contained in the certificate belongs to
the person, organization, server, or other entity noted in the certificate. A Certificate Authority's
obligation in such schemes is to verify an applicant's credentials, so that users (e.g., relying
parties) can trust the information in the Certificate Authority's certificates. This approach
however requires many predefined logistics and systems that are complex to administer and may
hinder the mobility and portability of calls; moreover, they are simply not available or practical
in a typical anonymous model. There are also questions of scalability given the number of PSTN
calls that occur daily on an anonymous basis.
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[0010] What is desired is an arrangement under which trusted peer-to-peer SIP (or any
similar multimedia protocol) communications can be provided against contextual media types for
media session calls where users have complete control over the who, the where, the when and the
how of the media session.
SUMMARY OF THE INVENTION
[0011] It is to be understood that both the following summary and the detailed description
are exemplary and explanatory and are intended to provide further explanation of the invention
as claimed. Neither the summary nor the description that follows is intended to define or limit
the scope of the invention to the, particular features mentioned in the summary or in the
description.
[0012] This invention provides a method, system and apparatus for allowing media context
sensitive SIP signaling exchange (such as voice) and call establishment while denying or
challenging any other session description protocol ("SDP") extension dialogs which might not be
desired (such as instant messaging, video, Web broadcasting or pushing, data and/or application
sharing and the like) by a user. The method and apparatus may further include defining user
client media policy preferences, the user media policy preferences establishing the parameters
for evaluating a media session request received by a user client, and providing the user client
media policy preferences to a policy enforcement point device, the policy enforcement point
device evaluating the media session request received by the user client and applying the user
client media policy preferences to the media session request. The method and apparatus may
further include utilizing a user client portal to gain access to a media policy database, the media
policy database providing storage for user client media policy preferences.
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[0013] In accordance with one aspect, the present invention provides method for providing
trusted contextual communications, by defining user client media policy preferences, the user
media policy preferences establishing the parameters for evaluating a media session request
received by a user client, and providing the user client media policy preferences to a policy
enforcement point device, the policy enforcement point device evaluating the media session
request received by the user client and applying the user client media policy preferences to the
media session request. The method may further include utilizing a user client portal to gain
access to a media policy database, the media policy database providing storage for the user client
media policy preferences. The method may further include validating the user client media
policy preferences and storing the user client media policy preferences. The method may yet
further include receiving an incoming media session request for the user client.
[0014] In accordance with another aspect, the present invention provides a system for
providing trusted contextual communications in a communication network. The system for a
providing trusted contextual communications in a communication network having a user client
portal, the user client portal providing access to system media session policy preferences, a
policy decision function module, the policy decision function module providing identity
management and media session policy modification to the trusted contextual communications
system, and a domain trust table, the domain trust table storing media session policy preferences.
The apparatus may further include a policy enforcement point, the policy enforcement point
device applying the media session policy preferences upon receipt of a media session request.
The apparatus may further include a session initiation protocol proxy device, the session
initiation protocol proxy device capable of establishing connections between a first user client
and a second user client.
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[0015] In accordance with yet another aspect, the present invention provides storage medium
storing a computer program which when executed by a processing unit performs a method for
providing trusted contextual communications on a communication network, the method
comprising by defining user client media policy preferences, the user media policy preferences
establishing the parameters for evaluating a media session request received by a user client, and
providing the user client media policy preferences to a policy enforcement point device, the
policy enforcement point device evaluating the media session request received by the user client
and applying the user client media policy preferences to the media session request. The method
may further include utilizing a user client portal to gain access to a media policy database, the
media policy database providing storage for the user client media policy preferences. The
method may further include validating the user client media policy preferences and storing the
user client media policy preferences.
6

BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A more complete understanding of the present invention, and the attendant
advantages and features thereof, will be more readily understood by reference to the following
detailed description when considered in conjunction with the accompanying drawings wherein:
[0017] FIG. 1 is a block diagram of a trusted contextual communication system of an
embodiment of the present invention;
[0018] FIG. 2 is a block diagram of a trusted contextual communication system of another
embodiment of the present invention;
[0019] FIG. 3 is a block diagram of a trusted contextual communication system within an
enterprise or hosted environment of another embodiment of the present invention;
[0020] FIG. 4 is a block diagram of a trusted contextual communication system spanning SIP
domains within a common IdM and Policy domain of another embodiment of the present
invention;
[0021] FIG. 5 is a block diagram of a trusted contextual communication system spanning SIP
domains between two IdM and Policy domains of another embodiment of the present invention;
[0022] FIG. 6 is a block diagram of a trusted contextual communication system deployed
within a SDP firewall host in accordance with the principles of the present invention;
[0023] FIG. 7 is a detailed flowchart of an incoming media session process for trusted
contextual communication in accordance with the principles of the present invention; and
[0024] FIG. 8 is a detailed flowchart of an outgoing media session process for trusted
contextual communication in accordance with the principles of the present invention.
7

DETAILED DESCRIPTION OF THE INVENTION
[0025] This invention provides a method, system and apparatus for allowing media context
sensitive SIP signaling exchange (such as voice) and call establishment while denying or
challenging any other session description protocol ("SDP") extension dialogs which might not be
desired (such as instant messaging, video, Web broadcasting or pushing, data and/or application
sharing and the like) by a user. In other words, since inter-human communications are a rather
personal matter, a user should decide or modify the permissible media and session types that a
calling party is allowed to make to that user. Accordingly, this invention allows for the
establishment of trusted peer-to-peer SIP communications by allowing only session and media
establishment that has been specified as permissible by the user. Consequently, additional media
session calls would require authorization either from the called party or from the session
management systems to allow for the establishment of the additional media session calls.
[0026] Referring now to the drawing figures in which like reference designators refer to like
elements, there is shown in FIG. 1, a block diagram of the basic architecture of a trusted
contextual communications ("TCC") system in accordance with the principles of die present
invention and designated generally as "100". The TCC system 100 comprises a user client portal
104, a policy decision function ("PDF") 106, a policy enforcement point ("PEP") 108 and a SIP
proxy 110. In general, a user client 102 is a computer system that accesses a (remote) service on
another computer using some kind of network. As used herein the term "user client" is meant to
include a wide range of computer-based systems, including but not limited to personal
computers, SIP-based phones, mobile phones, personal data assistants ("PDA") and like devices,
which use the SIP protocol or a similar protocol in a network environment.
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[0027] The user client portal 104 provides a user client 102 with the option to modify the
allowable media and session types at the appropriate level. For example, the user client 102 may
modify the policies at the domain, group or user specific levels conditioned upon allowance by a
central administrative policy manager, also known as a service administrator. The modified
policies may dictate, for example, that at the domain level, only voice media is permissible
(which could be the domain level default); at the group level, voice, video and instant messaging
media is permissible; while at the user level, in addition to all group level media being
permissible, web push or forcing and data collaboration are also permissible. These modified
user policies can be stored in a corresponding media policy database ("MPD") that may be
viewed as a specialized form of a security policy database ("SP"), which stores the security
policy of a network. In general, a security policy is a plan of action for tackling security issues,
or a set of regulations for maintaining a certain level of security in a network. A security policy
typically may be a high level document that states management commitment and intent in
relation to information security. A security policy may contain a company or an entity's
definition of information security and is supported by other policies (sub-policies), information
security objectives, procedures and other documents (e.g., references made to these documents).
[0028] In a similar way, the MPD stores the media policies that are to be applied to the
media and session types that are to be permissible to user clients and their corresponding session
callers. These media policies are "pushed" or provided to the identification management
("IdM") and policy PDF 106 for approval and validation, and storage in the central policy
repository that may include a domain trust table. The terms "push", "pushes", "pushing" and
"pushed" are used herein to broadly refer to a set of actions ranging from making data and
information available to a module, user, client, entity, network, subnetwork, device, apparatus,
9

system, subsystem or the like, to forcing or commanding that data or information be presented,
used, followed, obeyed, accessed, and the like. For example, in webpage pushing, a caller may
try to force a webpage to appear on a user client's communication device during a media session.
Similarly, in IM pushing, a caller may try to force an IM window popup (appear) on a user
client's communication device during a media session. Upon system validation and approval,
the user level MPD modifications are "pushed" or provided to the PEP 108 (e.g., SDP firewall
function).
[0029] In this embodiment, the PDF 106 comprises the lightweight directory access protocol
("LDAP"), and the IdM and policy features. The LDAP is a networking protocol for querying
and modifying directory services running over transmission control protoeol/internet protocol
("TCP/IP"). The PDF 106 provides the user level MPD policy modifications to the SDP firewall
(PEP) 108. In addition, the PDF 106 provides the application and network level identification
and authentication functions for the system 100.
[0030] A firewall is generally defined as a piece of hardware and/or software that functions
in a networked environment to prevent some communications forbidden by a security policy. A
firewall may sometimes be referred to as a border protection device ("BPD") or packet filter and
it has the basic task of controlling traffic between different zones of trust. These typical zones of
trust include the Internet (which is a zone with no trust) and an internal network (which is a zone
with high trust). The ultimate goal is to provide controlled connectivity between zones of
differing trust levels through the enforcement of a security policy and connectivity model based
on the least privilege principle. In this example, the user level MPD policy modifications are
applied by the SDP firewall 108 on a call by call basis. This configuration of PDF 106 and SDP
firewall (PEP) 108 may be referred to as a "provisioning model". In this model, the SDP
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firewall (PEP) 108 reports its decision-making capabilities to the PDF 108. The PDF 108 then
downloads relevant policies to the SDP firewall (PEP) 108, which in turn can make its own
decisions of which media sessions may proceed based on these policies. Alternatively, an
"outsourcing model" may be used where the policies are stored on the PDF 106 and whenever
the SDP firewall (PEP) 108 needs to make a decision, it sends all relevant information to the
PDF 106. The PDF 106 analyzes the information, makes a decision and relays it to the SDP
firewall (PEP) 108. The SDP firewall (PEP) 108 can then simply enforce that decision.
[0031] Continuing to refer to FIG. 1, the system 100 also includes a SIP proxy 110. The SIP
proxy 110 functions much like a "soft" private branch exchange ("PBX") in an IP network in
that it establishes connections (circuits) between the communication devices (e g., IP telephone
sets) of two users, maintains such connections as long as the users require them (e.g., channeling
voice signals between the users), and provides information for accounting purposes (e.g.,
metering call sessions).
[0032] The trusted contextual communications of the present invention scales by analyzing
the session request via the serving signaling proxy 110 or accelerated SDP firewall 108. In
incidents where there is established trust within a domain, then an extended anonymous trust
model outside of that domain will be available for specifically allowed session requests. It
should be noted that the trusted contextual communications invention may be used in
cooperation with external certificate authorities to enhance the end-to-end trust model.
[0033] FIG. 2 illustrates a block diagram of the basic architecture of a trusted contextual
communications ("TCC") system 200 in accordance with another embodiment of the present
invention. In this embodiment, the TCC system 200 is not coupled to a PDF 106, but instead
merges the PDF functionality into PEP 208. Accordingly, the TCC system 200 comprises a user
11

client portal 204, a PEP/PDF 208 and a SIP proxy 210. The user client portal 204 provides a
user client 202 with the option to modify the allowed media and session types at the appropriate
level. The components of TCC system 200 are similar to the components of TCC system 100
with the exception of the merger of PEP and PDF functions into PEP/PDF 208 and the storage of
the user and corresponding MPD policies in the SIP firewall policy base. As this embodiment
does not include the identification management (IdM) framework of system 100, the SIP proxy
210 will be responsible for handling the identification and authentication functions.
[0034] FIG. 3 illustrates a block diagram of the trusted contextual communications ("TCC")
system 300 deployed within an enterprise or hosted environment (e.g., FOO.com). In this
embodiment, the TCC system 300 includes a user client portal/secure sockets layer ("SSL")
virtual private network ("VPN")) 304, a PDF 306, a PEP 308 and a SIP proxy 310. The SSL is
used to provide privacy and integrity of the user client portal 304, and thus secure against an
unauthorized entity gaining access or control over the user client portal 304. In this embodiment
the functionality of user client portal 304, PDF 306, PEP 308 and SIP proxy 310 corresponds to
the functionality of user client portal 104, PDF 106, PEP 108 and SIP proxy 110 as previously
discussed with respect to FIG. 1. In this embodiment, the TCC system 300 further includes
various communication links 305, 307, 309 and 311, which provide signaling and SDP
interrogation among the user client portal 304, the PDF 306, the PEP 308, the SIP proxy 310 and
the user clients 302 and 312, and communication link 313 for a default media type (e.g., audio
only) selected by the user client 302. Therefore in this embodiment, the TCC system 300 would
permit anonymous inter-domain audio communications equivalent to the PSTN model. The
communication link 305 permits the user client 302 to utilize the user client portal 304 to push or
provide the user client media session preferences to the PDF 306. PDF 306 in turn uses
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communication link 307 to push the user client media session preferences, once approved by the
central administrative policy manager, to the SDP firewall (PEP) 308. The SIP proxy 310
references the user client media session preferences of SDP firewall (PEP) 308, and determines
whether a requested media session is permissible for die caller. In this way, the communication
links 311 provide for the signaling and SDP interrogation data to flow among the user client 302,
SIP proxy 310 and caller (user client 312). When caller (user client 312) has its trust established,
then the media session will include, at the least, the default media type selected by user client
302. In addition, specific domains of caller (user client 312) may be enabled for further
anonymous trust such as instant messaging ("IM") and video.
[0035] FiG. 4 ilustrates another embodiment of the trusted contextual communications ("TCC") system 300 spanning SIP domains within a common IdM and Policy domain. For
example, SIP proxy 310 could be FOO.com and have a sister domain called FOOFOO.com (SIP
proxy 314). Although each SEP domain would likely have its own SDP firewall (PEP) 308, 318,
the SIP domains could share a common IdM and Policy domain (PDF) 306. In this embodiment,
the TCC system 300 includes user client portals 304 and 316, a PDF 306, PEPs 308 and 318, and
SIP proxies 310 and 314. In this embodiment, the functionality of user client portal 304, PDF
306, PEP 308 and SIP proxies 310 and 314 corresponds to the functionality of user client portal
104, PDF 106, PEP 108 and SIP proxy 110 as previously discussed with respect to FIG. 1. In
this embodiment, the TCC system 300 further includes various communication links 305, 307,
309, 311 and 315, which provide signaling and SDP interrogation among the user client portals
304 and 316, the PDF 306, PEPs 308 and 318, and SIP proxies 310 and 314 and the user clients
302 and 312, and communication link 313 for a default media type (e.g., audio only) selected by
the user client 302 or user client 312. The functionality of communication links 305, 307, 309,
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311 and 313 corresponds to the functionality of communication links 305, 307, 309, 311 and 313
as previously discussed with respect to FIG. 3. In this embodiment, another communication link
315 provides for signaling and SDP interrogation between SIP proxies 310 and 314 (e.g.,
domains "FOO.com" and "F00F00.com"). This example also illustrates that the user client
portals 304, 316 implicitly control the SDP firewalls 308 and 318 via the dialog with PDF 306.
[0036] FIG. 5 illustrates another embodiment of the trusted contextual communications
("TCC") system 300 spanning SIP domains 310 and 314 between two IdM and Policy domains
306 and 320. For example, SIP proxy 310 could be F00.com and SIP proxy 314 could be
XYZ.com, a separate entity from F00.com. Accordingly, not only would each SIP domain
likely have its own SDP firewall (PEP) 308, 318, the SIP domain would most like have
individual IdM and Policy domains (PDF) 306 and 230. In this embodiment, the TCC system
300 includes user client portals 304 and 316, PDFs 306 and 320, PEPs 308 and 318, and SIP
proxies 310 and 314. In this embodiment, the functionality of user client portal 304, PDF 306,
PEP 308 and SIP proxies 310 and 314 corresponds to the functionality of user client portal 104.
PDF 106, PEP 108 and SIP proxy 110 as previously discussed with respect to FIG. 1. in this
embodiment, the TCC system 300 further includes various communication links 305, 307, 309,
311 and 315, which provide signaling and SDP interrogation among the user client portals 304
and 316, the PDF 306, PEPs 308 and 318, and SIP proxies 310 and 314 and the user clients 302
and 312, and communication link 313 for a default media type (e.g., audio only) selected by the
user client 302 or user client 312. The functionality of communication links 305, 307, 309, 311
and 313 corresponds to the functionality of communication links 305, 307, 309, 311 and 313 as
previously discussed with respect to FIGS. 3 and 4. In this embodiment, another communication
link 315 provides for signaling and SDP interrogation between SIP proxies 310 and 314 (e.g.,
14

domains FOO.com and XYZ.com). Similar to TCC system 300 illustrated in FIG. 4, this
example also illustrates that the user client portals implicitly control the SDP firewalls 308 and
318 via the dialog with PDFs 306 and 320.
[0037] FIG. 6 illustrates another embodiment of the trusted contextual communications
("TCC") system 300 deployed within a SDP firewall host. For example SIP proxy 310 could
remain F00.com and SIP proxy 314 could remain XYZ.com, a separate entity from F00.com,
as in FIG. 5, however, a third domain, PROTECTED.com has control over the user client portal
304, the IdM and Policy domains (PDF) 306 and the SDP firewall (PEP) 308. In this
embodiment, the functionality of user client portal 304, PDF 306, PEP 308 and SIP proxies 310
and 314 corresponds to the functionality of user client portal 104, PDF 106, PEP 108 and SIP
proxy 110 as previously discussed with respect to FIG. 1. The TCC system 300 further includes
various communication links 305, 307, 309, 311 and 315, which provide signaling and SDP
interrogation among the user client portal 304, the PDF 306, PEP 308 and SIP proxies 310 and
314 and the user clients 302 and 312, and communication link 313 for a default media type (e.g.,
audio only) selected by the usei client 302 or user client 312. The functionality of
communication links 305, 307, 309, 311 and 313 corresponds to the functionality of
communication links 305, 307, 309, 311 and 313 as previously discussed with respect to FIG. 5.
By placing the trusted contextual communication mechanism in the SDP firewall, a company
(e.g., PROTECTED.com") can stop all incoming media communications from entering its
communications network, and thereby provide a more secure communications network This
embodiment provides for blackballing all requests from a domain that may be known to be major
spamming domain.
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[0038] The operation of an embodiment of the trusted contextual communications system is
discussed with respect to the flowchart of FIG. 7. In step S100, the central administration
provisions domain level authorization and trust. In step S102, the user client 302 may access the
user client or personal agent portal 304. The user client 302 may modify the allowed media and
session types at the appropriate level by providing the user's preferences for handling calls from
specific parties (step S104). For example, the user client 302 may modify the policies at the
domain, group or user specific levels conditioned upon allowance by a central administrative
policy manager. These modified user and corresponding media policy database ("MPD")
settings or preferences are "pushed" or provided to the identification management ("IdM") and
policy PDF 306 (at step S106) for approval a and validation and storage in the central policy
repository (step S108). At step S110, a determination as to whether the MPD settings (e.g., user
client media policy preferences) were validated by the system. If not validated, the user client
302 is notified that the preferred MPD call policies were not acceptable (step S112). Otherwise,
at step S114, the preferred MPD settings are provided or "pushed" to the SDP firewall 308.
[0039] At step S116, an incoming call for the user client 302 arrives, and the identity trust
processing is performed. If the identity trust is not verified, then the incoming call request is
terminated at step S122. Otherwise, the SDP packet is interrogated at step S124 and the PDF
306 is consulted and the specific media preference for that specific caller is used. In the event
the caller is unknown, a default media (e.g., audio only) may be used (step S128). Additional
steps may include optimizing the performance of multiple calling instances form the same
known sources by introducing the concept of caching and tokens. For example, after a first time
call, the SDP firewall or proxy may provide a token to a caller, in order for the caller to use next
time they wish to call the user client. This means that the next time a call is made from the same
16

caller, the SDP firewall or proxy will see the token and automatically allow the call for the
proper media type based on previous policy establishment.
[0040] The operation of an outgoing call from the trusted contextual communications system
is discussed with respect to the flowchart of FIG. 8. In step S200, a user in the SIP domain
enters a remote domain SIP user identification or telephone number mapping ("ENUM")
identification and the initial request goes to the local registered proxy server 310 (step S202)
where it is analyzed by the proxy service 310 or SDP firewall 308 (step S204) for SDP syntax
dialogs that indicates the nature of the media session request. ENUM is a suite of protocols
seeking to unify the telephone system with the Internet by using E. 164 addresses with dynamic
delegation discovery system ("DDDS") and domain name system ("DNS"). The proxies
authorized session broker 306 compares the values with the domain trust table that exists within
the trusted contextual communications system (step S206). At step S208, if the authorized
session broker PDF 306 does not find the anonymous audio calls entry for the remote domain,
the session broker PDF 306 refuses to allow the proxy to forward the request on to its destination
domain (step S210). Upon finding the anonymous audio calls entry lor the remote domain, the
session broker PDF 306 then allows for the proxy 310 to forward the request on to its destination
domain (e.g., XYZ.com) at step S212.
[0041] At the receiving domain, the incoming request is in turn analyzed (step S214) and its
authorized session broker PDF 320 will reference its local domain trust table to validate
anonymous privileges (step S216). At step S218, if the authorized session broker PDF 320 does
not find the anonymous privileges valid, the session broker PDF 320 refuses to allow the proxy
314 to forward the request on to its ultimate destination (step S220). Upon validation the session
17

broker PDF 320 will in turn allow for the local proxy 318 to forward the session request to its
ultimate destination thereby completing the anonymous ring paradigm (step S224).
[0042] Once a communications media session has been established there may be a
requirement for additional media sessions. At this point, the called party (e.g., user client 312)
will be prompted by the authorization broker PDF 320 that such a request has been received (step
S224). The called party (e.g., user client 312) then has the ability to accept or deny the request
by the session broker intermediary PDF 320, not the calling party (step S228). If the called party
does not accept the prompt for the session broker PDF 320, the actual session request is not
forwarded by the local proxy 318 (step S230). Otherwise the local proxy 318 forwards the actual
session request and the media session is commenced (step S232). Afterwards, a cheek may he
made to determine if any additional media sessions have been requested (step S226). If no
additional media sessions have been requested the media session may be terminated at step S226.
[0043] Although the invention has been described in the various embodiments with respect
to STP/SDP communications, it is applicable to any similar multimedia protocols and
communications during a media session.
[0044] The present invention can be realized in hardware, software, or a combination of
hardware and software. An implementation of the method and system of the present invention
can be realized in a centralized fashion in one computing system or in a distributed fashion
where different elements are spread across several interconnected computing systems. Any kind
of computing system, or other apparatus adapted for carrying out the methods described herein,
is suited to perform the functions described herein.
[0045] A typical combination of hardware and software could be a specialized or general-
purpose computer system having one or more processing elements and a computer program
18

stored on a storage medium that, when loaded and executed, controls the computer system such
that it carries out the methods described herein. The present invention can also be embedded in a
computer program product, which comprises all the features enabling the implementation of the
methods described herein, and which, when loaded in a computing system is able to carry out
these methods. Storage medium refers to any volatile or non-volatile storage device.
[0046] Computer program or application in the present context means any expression, in any
language, code or notation, of a set of instructions intended to cause a system having an
information processing capability to perform a particular function either directly or after either or
both of the following a) conversion to another language, code or notation; b) reproduction in a
different material form. In addition, unless mention was made above to the contrary. It should be
noted that all of the accompanying drawings are not to scale. Significantly, this invention can be
embodied in other specific forms without departing from the spirit or essential attributes thereof,
and accordingly, reference should be had to the following claims, rather than to the foregoing
specification, as indicating the scope of the invention.
[0047] It will be appreciated by persons skilled in the art that the present invention is not
limited to what has been particularly shown and described herein above. A variety of
modifications and variations are possible in light of the above teachings without departing from
the spirit or essential attributes thereof, and accordingly, reference should be had to the following
claims, rather than to the foregoing specification, as indicating the scope of the of the invention.
[0048] It will be appreciated by persons skilled in the art that the present invention is not
limited to what has been particularly shown and described herein above. In addition, unless
mention was made above to the contrary, it should be noted that all of the accompanying
drawings are not to scale. A variety of modifications and variations are possible in light of the
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above teachings without departing from the scope and spirit of the invention, which is limited
only by the following claims.
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WE CLAIM;
1. A method for providing trusted contextual communications on a communication
network, the method comprising:
defining user client media policy preferences, the user media policy preferences
establishing the parameters for evaluating a media session request received by a user client; and
providing the user client media policy preferences to a policy enforcement point device,
the policy enforcement point device evaluating the media session request received by the user
client and applying the user client media policy preferences to the media session request.
2. The method of Claim 1, wherein defining user client media policy preferences
includes utilizing a user client portal to gain access to a media policy database, the media policy
database providing storage for the user client media policy preferences.
3. The method of Claim 1, wherein defining user client media policy preferences
includes validating the user client media policy preferences.
4. The method of Claim 3, wherein validating the user client media policy
preferences includes storing the user client media policy preferences in a domain trust table.
5. The method of Claim 1, further comprising receiving an incoming media session
request for the user client.
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6. The method of Claim 5, further comprising applying identity trust processing to
the incoming media session request for the user client.
7. The method of Claim 5, further comprising interrogating a session description
protocol data packet from the incoming media session request for the user client.
8. The method of Claim 6, further comprising providing a token to a caller of the
user client, the token providing an automatic media session connection.
9. A system for providing trusted contextual communication system on a
communication network, the system comprising:
a user client portal, the user client portal providing access to system media session policy
preferences;
a policy decision function module, the policy decision function module providing identity
management and media session policy modification to the trusted contextual communications
system; and
a domain trust table, the domain trust table storing the system media session policy
preferences.
10. The system of Claim 9 wherein the policy decision function module includes a
policy enforcement point, the policy enforcement point device applying the media session policy
preferences upon receipt of a media session request.
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11. The system of Claim 10 wherein the policy enforcement point is a session
description protocol firewall, the session description protocol firewall applying the media session
policy upon receipt of the media session request.
12. The system of Claim 9 wherein the media session policy preferences are user
client media policy preferences.
13. The system of Claim 9 further including a session initiation protocol proxy
device, the session initiation protocol proxy device capable of establishing connections between
a first user client and a second user client.
14. The system of Claim 9 further including a second policy decision function
module, the second policy decision function module providing identity management and media
session policy modification to the trusted contextual communications system.
15. The system of Claim 9 further including a second user client portal, the second
user client portal providing access to system media session policy preferences.
16. A storage medium storing a computer program which when executed by a
processing unit performs a method for providing trusted contextual communications on a
communication network, the method comprising:
defining user client media policy preferences, the user media policy preferences
establishing the parameters for evaluating a media session request received by a user client; and
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providing the user client media policy preferences to a policy enforcement point device,
the policy enforcement point device evaluating the media session request received by the user
client and applying the user client media policy preferences to the media session request.
17. The storage medium of Claim 16, wherein defining user client media policy
preferences includes utilizing a user client portal to gain access to a media policy database, the
media policy database providing storage for the user client media policy preferences.
18. The storage medium of Claim 16, wherein defining user client media policy
preferences include validating. the user client media policy preferences.
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19. The storage medium of Claim 18, wherein validating the user client media policy
preferences includes storing the user client media policy preferences in a domain trust table.
20. The storage medium of Claim 16, further comprising receiving an incoming
media session request for the user client.

This invention provides a method, system and apparatus for allowing media context
sensitive SIP signaling exchange (such as voice) and call establishment while denying or
challenging any other session description protocol ("SDP") extension dialogs which might not be
desired (such as instant messaging, video, Web broadcasting or pushing, data and/or application
sharing and the like) by a user. The method and apparatus may further include defining user
client media policy preferences, the user media policy preferences establishing the parameters
for evaluating a media session request received by a user client, and providing the user client
media policy preferences to a policy enforcement point device, the policy enforcement point
device evaluating the media session request received by the user client and applying the user
client media policy preferences to the media session request. The method and apparatus may
further include utilizing a user client portal to gain access to a media policy database, the media
policy database providing storage for user client media policy preferences.