SessionContext Class Reference

#include <SessionContext.h>

Inheritance diagram for SessionContext:

List of all members.

---

Detailed Description

The sessionContext class implements the state machine that knows jow to track a call fork answer/offer and intervene when necessary to facilitatre NAT traversal.

This includes adjusting SDP and configuring the Media Relay when needed.

Public Member Functions
	SessionContext (const SipMessage &sipRequest, const NatTraversalRules *pNatRules, const UtlString &handle, MediaRelay *pMediaRelayToUse, const RegistrationDB *pRegistrationDB, CallTrackerInterfaceForSessionContext *pOwningCallTracker)
virtual	~SessionContext ()
virtual UtlContainableType	getContainableType (void) const
virtual unsigned	hash () const
virtual int	compareTo (UtlContainable const *rhsContainable) const
bool	handleRequest (SipMessage &message, const char *address, int port, bool bFromCallerToCallee)
void	handleResponse (SipMessage &message, const char *address, int port)
void	handleCleanUpTimerTick (void)
virtual bool	doesEndpointsLocationImposeMediaRelay (void) const
	Determines whether or not a media relay needs to be employed in the media session between the caller and the callee baed o ntheir relative location in the network.
virtual bool	allocateMediaRelaySession (const UtlString &handleOfRequestingDialogContext, tMediaRelayHandle &relayHandle, int &callerRelayRtpPort, int &calleeRelayRtpPort)
	Requests the allocation of a media relay session on the Smmitron.
virtual tMediaRelayHandle	cloneMediaRelaySession (const UtlString &handleOfRequestingDialogContext, tMediaRelayHandle &relayHandleToClone, bool doSwapCallerAndCallee)
	Requests the cloning of an existing media relay session.
virtual bool	deallocateMediaRelaySession (const UtlString &handleOfRequestingDialogContext, const tMediaRelayHandle &relayHandle)
	Requests the de-allocation of a previously allocated media relay session.
virtual bool	setMediaRelayDirectionMode (const UtlString &handleOfRequestingDialogContext, const tMediaRelayHandle &relayHandle, MediaDirectionality mediaRelayDirectionMode, EndpointRole endpointRole)
	Configures the directionality of the media relay.
virtual bool	linkFarEndMediaRelayPortToRequester (const UtlString &handleOfRequestingDialogContext, const tMediaRelayHandle &relayHandle, const MediaDescriptor *pMediaDescriptor, EndpointRole endpointRoleOfRequester)
	Establishes the requester as the media destination for the far-end's media relay port.
virtual bool	getMediaRelayAddressToUseInSdp (UtlString &mediaRelayAddressToUse, EndpointRole endpointRole) const
	Computes the media relay IP address to use when patching SDP originating from endpoint designated by endpointRole param.
virtual int	getRtpRelayPortForMediaRelaySession (const tMediaRelayHandle &handle, EndpointRole endpointRole)
	Used to query the RTP port that a given MediaRelaySession has allocated to the endpoint whose role is passed as a parameter.
virtual void	reportDialogTrackerReadyForDeletion (const UtlString &handleOfRequestingDialogContext)
	Used to notify the owning SessionContext that the dialog a DialogTracker non longer needs to be tracked and that the DialogTracker object is redy for deletion.
virtual bool	getPacketProcessingStatsForMediaRelaySession (const tMediaRelayHandle &handle, PacketProcessingStatistics &stats)
	Retrieves the packet processing statistics for a given media relay session designated by its handle.
const EndpointDescriptor &	getEndpointDescriptor (EndpointRole endpointRole) const
ssize_t	getNumberOfTrackedDialogs (void) const
DialogTracker *	getDialogTrackerForMessage (const SipMessage &message) const
Static Public Member Functions
static EndpointDescriptor *	createCallerEndpointDescriptor (const SipMessage &sipRequest, const NatTraversalRules &natTraversalRules)
	Creates an endpoint descriptor representing the caller.
static EndpointDescriptor *	createCalleeEndpointDescriptor (const SipMessage &sipRequest, const NatTraversalRules &natTraversalRules, const RegistrationDB *pRegistrationDB)
	Creates an endpoint descriptor representing the callee.
Static Public Attributes
static const UtlContainableType	TYPE = "SessionContext"
Private Types
enum	SdpRecipient {   SDP_TOWARDS_CALLER,   SDP_TOWARDS_CALLEE }
Private Member Functions
UtlString	getDiscriminatingTagValue (const SipMessage &message, bool bFromCallerToCallee) const
	< Class type used for runtime checking
UtlString	getDiscriminatingTagValue (const SipMessage &message) const
DialogTracker *	getDialogTrackerForTag (const UtlString &tag) const
void	addDialogTrackerToList (const UtlString &tag, DialogTracker *pNewDialogTracker)
bool	removeDialogTrackerFromListAndDelete (const UtlString &tag)
DialogTracker *	allocateNewDialogTrackerBasedOnReference (const UtlString &discriminatingTag)
ssize_t	deleteDialogTrackersReadyForDeletion (void)
Private Attributes
UtlString	mSystemIdentificationString
CseqData	mDialogFormingInviteCseq
UtlString	mDialogOriginalFromTag
DialogTracker *	mpReferenceDialogTracker
EndpointDescriptor *	mpCaller
EndpointDescriptor *	mpCallee
const NatTraversalRules *	mpNatTraversalRules
UtlString	mHandle
MediaRelay *	mpMediaRelay
UtlHashMap	mDialogTrackersMap
CallTrackerInterfaceForSessionContext *	mpOwningCallTracker
vector< UtlString >	mListOfDialogTrackersReadyForDeletion
Friends
class	SessionContextTest
Classes
struct	CseqData

---

Member Enumeration Documentation

enum SdpRecipient [private]

Enumerator:

SDP_TOWARDS_CALLER
SDP_TOWARDS_CALLEE

---

Constructor & Destructor Documentation

SessionContext	(	const SipMessage &	sipRequest,
		const NatTraversalRules *	pNatRules,
		const UtlString &	handle,
		MediaRelay *	pMediaRelayToUse,
		const RegistrationDB *	pRegistrationDB,
		CallTrackerInterfaceForSessionContext *	pOwningCallTracker
	)

~SessionContext

(

)

[virtual]

---

Member Function Documentation

UtlContainableType getContainableType

(

void

)

const [virtual]

Implements UtlContainable.

unsigned hash

(

)

const [virtual]

Implements UtlContainable.

int compareTo

(

UtlContainable const *

rhsContainable

)

const [virtual]

Implements UtlContainable.

bool handleRequest	(	SipMessage &	message,
		const char *	address,
		int	port,
		bool	bFromCallerToCallee
	)

void handleResponse	(	SipMessage &	message,
		const char *	address,
		int	port
	)

void handleCleanUpTimerTick

(

void

)

bool doesEndpointsLocationImposeMediaRelay

(

void

)

const [virtual]

Determines whether or not a media relay needs to be employed in the media session between the caller and the callee baed o ntheir relative location in the network.

Implements SessionContextInterfaceForDialogTracker.

bool allocateMediaRelaySession	(	const UtlString &	handleOfRequestingDialogContext,
		tMediaRelayHandle &	relayHandle,
		int &	callerRelayRtpPort,
		int &	calleeRelayRtpPort
	)			[virtual]

Requests the allocation of a media relay session on the Smmitron.

Parameters:

[in]	handleOfRequestingDialogContext	- what it says
[out]	relayHandle	- handle to allocated media relay session
[out]	callerRelayRtpPort	- RTP port representing caller on the Symmitron. This is the RTP port the callee will be asked to send its media to.
[out]	calleeRelayRtpPort	- RTP port representing callee on the Symmitron. This is the RTP port the caller will be asked to send its media to.

Returns:

- true media relay session was properly allocated.

Implements SessionContextInterfaceForDialogTracker.

tMediaRelayHandle cloneMediaRelaySession	(	const UtlString &	handleOfRequestingDialogContext,
		tMediaRelayHandle &	relayHandleToClone,
		bool	doSwapCallerAndCallee
	)			[virtual]

Requests the cloning of an existing media relay session.

This cloning technique is utilized in scenarios where multiple unrelated dialogs use the same media relay session. The best example of such a scenario is a 3PCC call such as MOH.

Parameters:

[in]	handleOfRequestingDialogContext	- what it says
[in]	relayHandleToClone	- handle of media relay session to clone
[in]	doSwapCallerAndCallee	- indicates whether or not the roles of the caller and callee need to be inverted in the cloned session.

Returns:

- handle of the clone media relay session

Implements SessionContextInterfaceForDialogTracker.

bool deallocateMediaRelaySession	(	const UtlString &	handleOfRequestingDialogContext,
		const tMediaRelayHandle &	relayHandle
	)			[virtual]

Requests the de-allocation of a previously allocated media relay session.

Parameters:

[in]	handleOfRequestingDialogContext	- what it says
[in]	relayHandle	- handle of media relay session to de-allocate

Returns:

- true media relay session was properly de-allocated.

Implements SessionContextInterfaceForDialogTracker.

bool setMediaRelayDirectionMode	(	const UtlString &	handleOfRequestingDialogContext,
		const tMediaRelayHandle &	relayHandle,
		MediaDirectionality	mediaRelayDirectionMode,
		EndpointRole	endpointRole
	)			[virtual]

Configures the directionality of the media relay.

Note that the directionality specified in the 'mediaRelayDirectionMode' parameter is referenced from the caller.

Parameters:

[in]	handleOfRequestingDialogContext	- what it says
[in]	relayHandle	- handle of media relay session on which to apply the direction mode
[in]	mediaRelayDirectionMode	- direction mode to apply to media relay session referenced to the originator of the request.
[in]	endpointRole	- role of the originator of the request.

Returns:

- indicates whether or not the direction was set successfully.

Implements SessionContextInterfaceForDialogTracker.

bool linkFarEndMediaRelayPortToRequester	(	const UtlString &	handleOfRequestingDialogContext,
		const tMediaRelayHandle &	relayHandle,
		const MediaDescriptor *	pMediaDescriptor,
		EndpointRole	endpointRoleOfRequester
	)			[virtual]

Establishes the requester as the media destination for the far-end's media relay port.

Parameters:

[in]	handleOfRequestingDialogContext	- what it says
[in]	relayHandle	- handle of media relay session to apply the change
[in]	pMediaDescriptor	- pointer descriptor containing information about the requestor
[in]	endpointRoleOfRequester	- role of requestor.

Returns:

- indicates whether or not the destination was set successfully.

Implements SessionContextInterfaceForDialogTracker.

bool getMediaRelayAddressToUseInSdp	(	UtlString &	mediaRelayAddressToUse,
		EndpointRole	endpointRole
	)			const [virtual]

Computes the media relay IP address to use when patching SDP originating from endpoint designated by endpointRole param.

Parameters:

[out]	mediaRelayAddressToUse	- will contain the Symmitron address to use when patching SDP
[in]	endpointRole	- role of endpoint making the request.

Returns:

true if media relay's native IP address is to be used. false if media relay's public IP address is to be used

Implements SessionContextInterfaceForDialogTracker.

int getRtpRelayPortForMediaRelaySession	(	const tMediaRelayHandle &	handle,
		EndpointRole	endpointRole
	)			[virtual]

Used to query the RTP port that a given MediaRelaySession has allocated to the endpoint whose role is passed as a parameter.

Parameters:

[in]

handle

- handle of media relay session to query ]param [in] endpointRole - role of endpoint for which to retrieve RTP port

Returns:

- PORT_NONE if failed, otherwise RTP port number

Implements SessionContextInterfaceForDialogTracker.

void reportDialogTrackerReadyForDeletion

(

const UtlString &

handleOfRequestingDialogContext

)

[virtual]

Used to notify the owning SessionContext that the dialog a DialogTracker non longer needs to be tracked and that the DialogTracker object is redy for deletion.

Parameters:

[in]

handleOfRequestingDialogContext

- what it says

Implements SessionContextInterfaceForDialogTracker.

bool getPacketProcessingStatsForMediaRelaySession	(	const tMediaRelayHandle &	handle,
		PacketProcessingStatistics &	stats
	)			[virtual]

Retrieves the packet processing statistics for a given media relay session designated by its handle.

Parameters:

[in]	handle	- handle of media relay session for which to obtain packet processing stats
[out]	stats	- structure that will receive the requested stats information

Returns:

true operation succeeds, false otherwise

Implements SessionContextInterfaceForDialogTracker.

const EndpointDescriptor & getEndpointDescriptor

(

EndpointRole

endpointRole

)

const

ssize_t getNumberOfTrackedDialogs

(

void

)

const

DialogTracker * getDialogTrackerForMessage

(

const SipMessage &

message

)

const

EndpointDescriptor * createCallerEndpointDescriptor	(	const SipMessage &	sipRequest,
		const NatTraversalRules &	natTraversalRules
	)			[static]

Creates an endpoint descriptor representing the caller.

Parameters:

[in]	sipRequest	- request from which caller endpoint descritptor will be initialized
[in]	natTraversalRules	- rules containing valuable topology info to initialize descriptor

Returns:

new EndpointDescriptor instance representing the caller. The invoker of this method is responsible for deleting the instance once it is done with it.

EndpointDescriptor * createCalleeEndpointDescriptor	(	const SipMessage &	sipRequest,
		const NatTraversalRules &	natTraversalRules,
		const RegistrationDB *	pRegistrationDB
	)			[static]

Creates an endpoint descriptor representing the callee.

Parameters:

[in]	sipRequest	- request from which callee endpoint descritptor will be initialized
[in]	natTraversalRules	- rules containing valuable topology info to initialize descriptor
[in]	pRegistrationDB	- pointer to registration DB sometimes used to deduce the callee's location info

Returns:

new EndpointDescriptor instance representing the callee. The invoker of this method is responsible for deleting the instance once it is done with it.

UtlString getDiscriminatingTagValue	(	const SipMessage &	message,
		bool	bFromCallerToCallee
	)			const [private]

< Class type used for runtime checking

UtlString getDiscriminatingTagValue

(

const SipMessage &

message

)

const [private]

DialogTracker * getDialogTrackerForTag

(

const UtlString &

tag

)

const [private]

void addDialogTrackerToList	(	const UtlString &	tag,
		DialogTracker *	pNewDialogTracker
	)			[private]

bool removeDialogTrackerFromListAndDelete

(

const UtlString &

tag

)

[private]

DialogTracker * allocateNewDialogTrackerBasedOnReference

(

const UtlString &

discriminatingTag

)

[private]

ssize_t deleteDialogTrackersReadyForDeletion

(

void

)

[private]

---

Friends And Related Function Documentation

friend class SessionContextTest [friend]

---

Member Data Documentation

const UtlContainableType TYPE = "SessionContext" [static]

Reimplemented from UtlContainable.

UtlString mSystemIdentificationString [private]

CseqData mDialogFormingInviteCseq [private]

UtlString mDialogOriginalFromTag [private]

DialogTracker* mpReferenceDialogTracker [private]

EndpointDescriptor* mpCaller [private]

EndpointDescriptor* mpCallee [private]

const NatTraversalRules* mpNatTraversalRules [private]

UtlString mHandle [private]

MediaRelay* mpMediaRelay [private]

UtlHashMap mDialogTrackersMap [private]

CallTrackerInterfaceForSessionContext* mpOwningCallTracker [private]

vector<UtlString> mListOfDialogTrackersReadyForDeletion [private]