Reusing listening points in JAIN-SIP (jsip)

Question

I am building a java application using SIP over websockets and working as b2bua, i.e. this application registers a number of sip users on another SIP server.

I was wondering if there is a way to somehow reuse an existing listening point? It seems that for each of the SIP clients I should create SipStack, SipListeningPoint, SipProvider and then call SipProvider's sendRequest to actually send SIP message to the destination server. The creation of a SipListeningPoint however allocates a new socket to accept incoming connections (which I don't really need), so I need one open socket for each SIP client I am registering on the remote server.

I tried to reuse SipListeningPoint, but there is a limitation that only one listening point is allowed per SipStack. I also tried to reuse SipProvider, but it leads to an exception in SSLStateMachine.

javax.net.ssl.SSLException: Received fatal alert: handshake_failure
    at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)
    at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1666)
    at sun.security.ssl.SSLEngineImpl.fatal(SSLEngineImpl.java:1634)
    at sun.security.ssl.SSLEngineImpl.recvAlert(SSLEngineImpl.java:1800)
    at sun.security.ssl.SSLEngineImpl.readRecord(SSLEngineImpl.java:1083)
    at sun.security.ssl.SSLEngineImpl.readNetRecord(SSLEngineImpl.java:907)
    at sun.security.ssl.SSLEngineImpl.unwrap(SSLEngineImpl.java:781)
    at javax.net.ssl.SSLEngine.unwrap(SSLEngine.java:624)
    at gov.nist.javax.sip.stack.SSLStateMachine.unwrap(SSLStateMachine.java:303)
    at gov.nist.javax.sip.stack.SSLStateMachine.unwrap(SSLStateMachine.java:244)
    at gov.nist.javax.sip.stack.NioTlsWebSocketMessageChannel.addBytes(NioTlsWebSocketMessageChannel.java:282)
    at gov.nist.javax.sip.stack.NioTcpMessageChannel.readChannel(NioTcpMessageChannel.java:121)
    at gov.nist.javax.sip.stack.NioTcpMessageProcessor$ProcessorTask.read(NioTcpMessageProcessor.java:154)
    at gov.nist.javax.sip.stack.NioTcpMessageProcessor$ProcessorTask.run(NioTcpMessageProcessor.java:344)
    at java.lang.Thread.run(Thread.java:745)

(Yes I know that this stack trace usually means that there is some issue with an SSL certificate. But SSL connection establishes successfully when I create separate listening points for each sip user or when I register just one sip user)

Here are SipStack properties I set:

properties.setProperty("javax.sip.STACK_NAME", s"im.dlg.sip:$localAddress:$transport")
properties.setProperty("javax.sip.AUTOMATIC_DIALOG_SUPPORT", "on") // must be on to leverage dialog usage!
properties.setProperty("gov.nist.javax.sip.DELIVER_RETRANSMITTED_ACK_TO_LISTENER", "true")
properties.setProperty("gov.nist.javax.sip.REENTRANT_LISTENER", "false")
properties.setProperty("gov.nist.javax.sip.MESSAGE_PROCESSOR_FACTORY", "gov.nist.javax.sip.stack.NioMessageProcessorFactory")
properties.setProperty("gov.nist.javax.sip.THREAD_POOL_SIZE", "10")

I am using javax.sip:jain-sip-ri:1.2.265.