javax.sip

Interface SipStack

All Known Subinterfaces:

SipStackExt

All Known Implementing Classes:

SipStackImpl

public interface SipStack

This interface represents the management interface of a SIP stack implementing this specification and as such is the interface that defines the management/architectural view of the SIP stack. It defines the methods required to represent and provision a proprietary SIP protocol stack.

This SipStack interface defines the methods that are be used by an application implementing the SipListener interface to control the architecture and setup of the SIP stack. These methods include:

• Creation/deletion of SipProvider's that represent messaging objects that can be used by an application to send Requestand Response messages statelessly or statefully via Client and Server transactions.
• Creation/deletion of ListeningPoint's that represent different ports and transports that a SipProvider can use to send and receive messages.

Architecture:
This specification mandates a one-to-many relationship between a SipStack and a SipProvider. There is a one-to-many relationship between a SipStack and a ListeningPoint.

SipStack Creation
An application must create a SipStack by invoking the SipFactory.createSipStack(Properties)method, ensuring the SipFactory.setPathName(String)is set. Following the naming convention defined in SipFactory, the implementation of the SipStack interface must be called SipStackImpl. This specification also defines a stack configuration mechanism using java.util.Properties, therefore this constructor must also accept a properties argument:

public SipStackImpl(Properties properties) {}

The following table documents the static configuration properties which can be set for an implementation of a SipStack. This specification doesn't preclude additional values within a configuration properties object if understood by the underlying implementation. In order to change these properties after a SipStack has been initialized the SipStack must be deleted and recreated:

SipStack Property	Description
javax.sip.IP_ADDRESS	Deprecated v1.2. It is recommended in this specification that the IP Address should be set using the enhanced ListeningPoint architecture, therefore this property is no longer mandatory. When this parameter is specified as null, a singleton stack instance will be created and returned by the SipFactory and the IP Address attributes can be managed via the createListeningPoint(String, int, String) method. For backwards compatability if this flag is set the SipFactory will return a new SipStack instance each time a SipStack is created with a new IP Address. This configuration parameter will become the default IP address of the SipStack. The SIP Factory will return any any existing instance of SipStack that already exist for this IP Address.
javax.sip.STACK_NAME	Sets a user friendly name to identify the underlying stack implementation to the property value i.e. NISTv1.2. The stack name property should contain no spaces. This property is mandatory.
javax.sip.OUTBOUND_PROXY	Sets the outbound proxy of the SIP Stack. The fromat for this string is "ipaddress:port/transport" i.e. 129.1.22.333:5060/UDP. This property is optional.
javax.sip.ROUTER_PATH	Sets the fully qualified classpath to the application supplied Router object that determines how to route messages when the stack cannot make a routing decision ( ie. non-sip URIs). In version 1.2 of this specification, out of Dialog SIP URIs are routed by the Routing algorithm defined in RFC 3261 which is implemented internally by the stack provided that javax.sip.USE_ROUTER_FOR_ALL_URIS is set to false. In this case, the installed Router object is consulted for routing decisions pertaining to non-SIP URIs. An application defined Router object must implement the javax.sip.Router interface. This property is optional.
javax.sip.EXTENSION_METHODS	This configuration value informs the underlying implementation of supported extension methods that create new dialog's. This list must not include methods that are natively supported by this specification such as INVITE, SUBSCRIBE and REFER. This configuration flag should only be used for dialog creating extension methods, other extension methods that don't create dialogs can be used using the method parameter on Request assuming the implementation understands the method. If more than one method is supported in this property each extension should be seprated with a colon for example "FOO:BAR". This property is optional.
javax.sip.RETRANSMISSION_FILTER	Deprecated v1.2. Applications can request retransmission alerts from the ServerTransaction.enableRetransmissionAlerts(). The default retransmission behaviour of this specification is dependent on the application core and is defined as follows: User Agent Client: Retransmissions of ACK Requests are the responsibility of the application. All other retansmissions are handled by the SipProvider. User Agent Server: Retransmissions of 1xx, 2xx Responses are the responsibility of the application. All other retansmissions are handled by the SipProvider. Stateful Proxy: As stateful proxies have no Invite transactions all retransmissions are handled by the SipProvider. Stateless Proxy: As stateless proxies are not transactional all retransmissions are the responsibility of the application and will not be handled the SipProvider. This filter can be viewed as a helper function for User Agents that can be set by an application to prevent the application from handling retransmission of ACK Requests, 1xx and 2xx Responses for INVITE transactions, i.e. the SipProvider will handle the retransmissions. This utility is useful for hiding protocol retransmission semantics from higher level programming environments. The acceptable values are ON/OFF. This property is optional, therefore if not supplied the default is OFF.
javax.sip.AUTOMATIC_DIALOG_SUPPORT	This property specifies the defined values 'ON' and 'OFF'. The default value is 'ON'. The default behavior represents a common mode of stack operation and allows the construction of simple user agents. This property is optional. This is summarized as: A dialog gets created on a dialog creating transaction. The first respose having both a From and a To tag creates the transaction. The first 2xx response to the transaction will drive the dialog to the CONFIRMED state. The ability to turn of dialog support is motivated by dialog free servers (such as proxy servers) that do not want to pay the overhead of the dialog layer and user agents that may want to create multiple dialogs for a single INVITE (as a result of forking by proxy servers). The following behavior is defined when the configuration parameter is set to 'OFF'. The application is responsible to create the Dialog if desired. The application may create a Dialog and associate it with a response (provisional or final) of a dialog creating request. Since v1.2.
javax.sip.FORKABLE_EVENTS	Comma separated list of events for which the implementation should expect forked SUBSCRIBE dialogs. Each element of this list must have the syntax packagename.eventname This configuration parameter is provided in order to support the following behavior ( defined in RFC 3265): Successful SUBSCRIBE requests will normally receive only one 200-class response; however, due to forking, the subscription may have been accepted by multiple nodes. The subscriber MUST therefore be prepared to receive NOTIFY requests with "From:" tags which differ from the "To:" tag received in the SUBSCRIBE 200-class response. If multiple NOTIFY messages are received in different dialogs in response to a single SUBSCRIBE message, each dialog represents a different destination to which the SUBSCRIBE request was forked. Each event package MUST specify whether forked SUBSCRIBE requests are allowed to install multiple subscriptions.If such behavior is not allowed, the first potential dialog-establishing message will create a dialog. All subsequent NOTIFY messages which correspond to the SUBSCRIBE message (i.e., match "To","From", "From" header "tag" parameter, "Call-ID", "CSeq", "Event", and "Event" header "id" parameter) but which do not match the dialog would be rejected with a 481 response. This property is optional. Since v1.2
javax.sip.USE_ROUTER_FOR_ALL_URIS	If set to true then the application installed Router is consulted for ALL routing decisions (ie. both out of dialog SIP and non-SIP request URI's -- identitcal to the behavior supported in v1.1 of this specification). If set to false the user installed router will only be consulted for routing of Non-SIP URIs. Implementations may thus provide support for sophisticated operations such as DNS lookup for SIP URI's using the proceedures defined in RFC 3263 (support for RFC 3263 is not mandatory for this specification). This property is optional. The default value for this parameter is true. Since v1.2.

Version:

1.2

Author:

BEA Systems, NIST

See Also:

SipFactory, SipProvider

Method Summary

Methods

Modifier and Type	Method and Description
ListeningPoint	createListeningPoint(int port, String transport) Deprecated. Since v1.2. This has been replaced by createListeningPoint(String, int, String) For backwards compatibility with v1.1 implementations should support this method. Implementations should throw TransportNotSupportedException if the Properties specified during stack creation do not include an IP Address.
ListeningPoint	createListeningPoint(String ipAddress, int port, String transport) Creates a ListeningPoint a given IP address, port and transport.
SipProvider	createSipProvider(ListeningPoint listeningPoint) Creates a new peer SipProvider on this SipStack on a specified ListeningPoint and returns a reference to the newly created SipProvider object.
void	deleteListeningPoint(ListeningPoint listeningPoint) Deletes the specified ListeningPoint attached to this SipStack.
void	deleteSipProvider(SipProvider sipProvider) Deletes the specified peer SipProvider attached to this SipStack.
String	getIPAddress() Gets the IP Address that identifies this SipStack instance.
Iterator	getListeningPoints() Returns an Iterator of existing ListeningPoints created by this SipStack.
Router	getRouter() Gets the Router object that identifies the default Router information of this SipStack.
Iterator	getSipProviders() Returns an Iterator of existing SipProviders that have been created by this SipStack.
String	getStackName() Gets the user friendly name that identifies this SipStack instance.
boolean	isRetransmissionFilterActive() Deprecated. Since v1.2. This retransmission filter property has been deprecated as a SIP Stack property. Applications can enable retransmission alerts by using the ServerTransaction.enableRetransmissionAlerts() method.
void	start() This method initiates the active processing of the stack.
void	stop() This methods initiates the shutdown of the stack.

Method Detail

createSipProvider

SipProvider createSipProvider(ListeningPoint listeningPoint)
                              throws ObjectInUseException

Creates a new peer SipProvider on this SipStack on a specified ListeningPoint and returns a reference to the newly created SipProvider object. The newly created SipProvider is implicitly attached to this SipListener upon execution of this method, by adding the SipProvider to the list of SipProviders of this SipStack once it has been successfully created.

Parameters:

listeningPoint - listening point for this SipProvider.

Returns:

the newly created SipProvider been started.

Throws:

ObjectInUseException - if another SipProvider is already associated with this ListeningPoint.

deleteSipProvider

void deleteSipProvider(SipProvider sipProvider)
                       throws ObjectInUseException

Deletes the specified peer SipProvider attached to this SipStack. The specified SipProvider is implicitly detached from this SipStack upon execution of this method, by removing the SipProvider from the SipProviders list of this SipStack. Deletion of a SipProvider does not automatically delete the SipProvider's ListeningPoint from the SipStack.

Parameters:

sipProvider - the peer SipProvider to be deleted from this SipStack.

Throws:

ObjectInUseException - if the specified SipProvider cannot be deleted because the SipProvider is currently in use.

getSipProviders

Iterator getSipProviders()

Returns an Iterator of existing SipProviders that have been created by this SipStack. All of the SipProviders of this SipStack will belong to the same stack vendor.

Returns:

the list of Providers attached to this Sipstack.

createListeningPoint

ListeningPoint createListeningPoint(int port,
                                  String transport)
                                    throws TransportNotSupportedException,
                                           InvalidArgumentException

Deprecated. Since v1.2. This has been replaced by createListeningPoint(String, int, String) For backwards compatibility with v1.1 implementations should support this method. Implementations should throw TransportNotSupportedException if the Properties specified during stack creation do not include an IP Address.

Creates a new ListeningPoint on this SipStack on a specified port and transport and the default IP address of this stack as specified by the SipStack IP address configuration parameter, and returns a reference to the newly created ListeningPoint object. The newly created ListeningPoint is implicitly attached to this SipStack upon execution of this method, by adding the ListeningPoint to the List of ListeningPoints of this SipStack once it has been successfully created.

Parameters:

port - the port of the new ListeningPoint.

transport - the transport of the new ListeningPoint.

Returns:

the ListeningPoint attached to this SipStack.

Throws:

TansportNotSupportedException - if the specified transport is not supported by this SipStack.

InvalidArgumentException - if the specified port is invalid.

TransportNotSupportedException

createListeningPoint

ListeningPoint createListeningPoint(String ipAddress,
                                  int port,
                                  String transport)
                                    throws TransportNotSupportedException,
                                           InvalidArgumentException

Creates a ListeningPoint a given IP address, port and transport. If this method is used, the IP address of the stack is ignored and a listening point is created with the given parameters. This support is useful for multi-homed hosts which may have to listen at multiple IP addresses and have different dialogs for each IP address.

Returns:

ListeningPoint that uses the IP address port and transport.

Throws:

SipException - if the Listening point cannot be created for any reason or if the stack has specified a default IP address that differs from the IP address specified for this method.

InvalidArgumentException

TransportNotSupportedException

Since:

1.2

deleteListeningPoint

void deleteListeningPoint(ListeningPoint listeningPoint)
                          throws ObjectInUseException

Deletes the specified ListeningPoint attached to this SipStack. The specified ListeningPoint is implicitly detached from this SipStack upon execution of this method, by removing the ListeningPoint from the ListeningPoints list of this SipStack.

Parameters:

listeningPoint - the SipProvider to be deleted from this SipStack.

Throws:

ObjectInUseException - if the specified ListeningPoint cannot be deleted because the ListeningPoint is currently in use.

getListeningPoints

Iterator getListeningPoints()

Returns an Iterator of existing ListeningPoints created by this SipStack. All of the ListeningPoints of this SipStack belong to the same stack vendor.

Returns:

an Iterator containing all existing ListeningPoints created by this SipStack. Returns an empty Iterator if no ListeningPoints exist.

getStackName

String getStackName()

Gets the user friendly name that identifies this SipStack instance. This value is set using the Properties object passed to the SipFactory.createSipStack(Properties)method upon creation of the SipStack object.

Returns:

a string identifing the stack instance

getIPAddress

String getIPAddress()

Gets the IP Address that identifies this SipStack instance. Every SipStack object may have an IP Address. This specification recommends associating the IP address with the ListeningPoint. For backwards compatability if an IP address is specified in the Properties object passed to the SipFactory.createSipStack(Properties) method upon creation of the SipStack object then this becomes the default IP address of the SipStack object, ListeningPoints can then be created on this IP Address.

Returns:

a string identifing the IP Address. Null if there is no default IP address associated with the stack instance.

getRouter

Router getRouter()

Gets the Router object that identifies the default Router information of this SipStack. This value is set using the Properties object passed to the SipFactory.createSipStack(Properties)method upon creation of the SipStack object.

Returns:

the Router object identifying the Router information.

stop

void stop()

This methods initiates the shutdown of the stack. The stack will terminate all ongoing transactions, without providing notificatin to the listener, close all listening points and release all resources associated with this stack. Note that this is a hard stop and should be used with care. The application may build graceful stop measures if needed, however the implementation is expected to immediately release any resources such as threads sockets and buffers that are allocated to this stack.

Since:

1.2

start

void start()
           throws SipException

This method initiates the active processing of the stack. This method is used to start the stack after the necessary SipProviders have been created. After calling this method, the stack can handle incoming requests and responses on the ListeningPoints associated to the SipProviders.

Throws:

SipException - if the stack cannot be started due to some system level failure.

Since:

1.2

isRetransmissionFilterActive

boolean isRetransmissionFilterActive()

Deprecated. Since v1.2. This retransmission filter property has been deprecated as a SIP Stack property. Applications can enable retransmission alerts by using the ServerTransaction.enableRetransmissionAlerts() method.

This method returns the value of the retransmission filter helper function for User Agent applications. This value is set using the Properties object passed to the SipFactory.createSipStack(Properties)method upon creation of the SipStack object.

The default value of the retransmission filter boolean is false . When this value is set to true, retransmissions of ACK's and 2xx responses to an INVITE transaction are handled by the SipProvider, hence the application will not receive Timeout.RETRANSMITnotifications encapsulated in TimeoutEvent's, however an application will be notified if the underlying transaction expires with a Timeout.TRANSACTIONnotification encapsulated in a TimeoutEvent.

Returns:

the value of the retransmission filter, true if the filter is set, false otherwise.