基于JAINSIP协议栈的一个简单SIP服务器实现流程

Bertha 。 2022-06-15 12:17 866阅读 0赞

SIP服务器采用B2BUA，sip呼叫控制实现流程

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 </div> SIP<a href="http://www.rosoo.net/a/list_52_1.html" style="padding:0px; margin:0px; color:rgb(37,110,177); text-decoration:none" rel="nofollow">服务器</a>采用B2BUA，sip呼叫控制实现流程：&nbsp; INVITE的请求：&nbsp; 收到INVITE后，克隆INVITE消息。替换Request&nbsp;URI被叫注册的地址。&nbsp; 替换VIA头为服务器地址。通过该INVITE请求得到客户端事务并通过&nbsp; 该事务来发送INVITE请求。&nbsp; 180,200&nbsp;OK响应的处理：&nbsp; 根据返回的响应码创建新的响应。&nbsp; 替换CONTACT头地址为服务器的地址。&nbsp; 拷贝原响应中的媒体内容至新的响应中。&nbsp; 通过INVITE中保存下来的服务端事务发送响应消息。&nbsp; ACK的处理：&nbsp; 从ACK请求中得到序列数。&nbsp; 通过被叫对话来创建新的ACK请求。&nbsp; 通过被叫对话发送ACK请求。&nbsp; BYE的处理流程：&nbsp; 根据被叫端的客户端事务得到发送给被叫的INVITE请求，根据INVITE请求创建BYE消息。&nbsp; BYE响应消息处理流程：&nbsp; 根据DIALOG得到服务端事务，并由此得到BYE请求。根据BYE请求创建响应。&nbsp; CANCEL的处理流程：&nbsp; 向主叫响应CANCEL&nbsp;200&nbsp;OK。&nbsp; 根据客户端事务得到发送给主叫的INVITE请求中的URI，CALLID，FROM，TO，VIA头域来创建CANCEL请求。&nbsp; 注：非200&nbsp;OK的ACK响应是由<a href="http://www.rosoo.net/a/list_46_1.html" style="padding:0px; margin:0px; color:rgb(37,110,177); text-decoration:none" rel="nofollow">协议</a>栈来实现的，不需要应用层来发送。也就是说，ACK消息不会经过应用层。&nbsp; <pre style="padding:0px; margin-top:0px; margin-bottom:1em; font-family:'Courier New',monospace; width:727.641px; overflow:auto; background:rgb(247,247,247)">package com.voip.sipphone; 
import gov.nist.javax.sip.address.SipUri; 
import gov.nist.javax.sip.header.CSeq; 
import gov.nist.javax.sip.header.Contact; 
import gov.nist.javax.sip.header.ContentLength; 
import gov.nist.javax.sip.header.ContentType; 
import gov.nist.javax.sip.header.From; 
import gov.nist.javax.sip.header.Via; 
import java.text.ParseException; 
import java.util.ArrayList; 
import java.util.Hashtable; 
import java.util.List; 
import java.util.Properties; 
import java.util.Timer; 
import javax.sip.*; 
import javax.sip.address.Address; 
import javax.sip.address.AddressFactory; 
import javax.sip.address.URI; 
import javax.sip.header.CallIdHeader; 
import javax.sip.header.ContactHeader; 
import javax.sip.header.ExpiresHeader; 
import javax.sip.header.FromHeader; 
import javax.sip.header.Header; 
import javax.sip.header.HeaderFactory; 
import javax.sip.header.MaxForwardsHeader; 
import javax.sip.header.RecordRouteHeader; 
import javax.sip.header.ToHeader; 
import javax.sip.header.ViaHeader; 
import javax.sip.message.MessageFactory; 
import javax.sip.message.Request; 
import javax.sip.message.Response; 
public class SipPhone implements SipListener 
{ 
 public void processDialogTerminated(DialogTerminatedEvent arg0) { 
 // TODO Auto-generated method stub 
 System.out.println("processDialogTerminated " + arg0.toString()); 
 } 
 public void processIOException(IOExceptionEvent arg0) { 
 // TODO Auto-generated method stub 
 System.out.println("processIOException " + arg0.toString()); 
 } 
 
 /** 
 * 保存当前注册的用户 
 */ 
 private static Hashtable&lt;URI, URI&gt; currUser = new Hashtable(); 
 
 
 /** 
 * @author software 
 * 注册定时器 
 */ 
 class TimerTask extends Timer 
 { 
 /** 
 * default constructor 
 */ 
 public TimerTask() 
 { 
 
 } 
 
 /** 
 * 如果定时任务到，则删除该用户的注册信息 
 */ 
 public void run() 
 { 
 
 } 
 } 
 
 
 /** 
 * 服务器侦听IP地址 
 */ 
 private String ipAddr = "192.168.0.20"; 
 
 
 /** 
 * 服务器侦听端口 
 */ 
 private int port = 5060; 
 
 /** 
 * 处理register请求 
 * @param request 请求消息 
 */ 
 private void processRegister(Request request, RequestEvent requestEvent) 
 { 
 if (null == request) 
 { 
 System.out.println("processInvite request is null."); 
 return; 
 } 
 //System.out.println("Request " + request.toString()); 
 ServerTransaction serverTransactionId = requestEvent.getServerTransaction(); 
 
 try 
 { 
 Response response = null; 
 ToHeader head = (ToHeader)request.getHeader(ToHeader.NAME); 
 Address toAddress = head.getAddress(); 
 URI toURI = toAddress.getURI(); 
 ContactHeader contactHeader = (ContactHeader) request.getHeader("Contact"); 
 Address contactAddr = contactHeader.getAddress(); 
 URI contactURI = contactAddr.getURI(); 
 System.out.println("processRegister from: " + toURI + " request str: " + contactURI); 
 int expires = request.getExpires().getExpires(); 
 // 如果expires不等于0,则为注册，否则为注销。 
 if (expires != 0 || contactHeader.getExpires() != 0) 
 { 
 currUser.put(toURI, contactURI); 
 System.out.println("register user " + toURI); 
 } 
 else 
 { 
 currUser.remove(toURI); 
 System.out.println("unregister user " + toURI); 
 } 
 
 response = msgFactory.createResponse(200, request); 
 System.out.println("send register response : " + response.toString()); 
 
 if(serverTransactionId == null) 
 { 
 serverTransactionId = sipProvider.getNewServerTransaction(request); 
 serverTransactionId.sendResponse(response); 
 //serverTransactionId.terminate(); 
 System.out.println("register serverTransaction: " + serverTransactionId); 
 } 
 else 
 { 
 System.out.println("processRequest serverTransactionId is null."); 
 } 
 
 } 
 catch (ParseException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 } 
 
 /** 
 * 处理invite请求 
 * @param request 请求消息 
 */ 
 private void processInvite(Request request, RequestEvent requestEvent) 
 { 
 if (null == request) 
 { 
 System.out.println("processInvite request is null."); 
 return; 
 } 
 try 
 { 
 // 发送100 Trying 
 serverTransactionId = requestEvent.getServerTransaction(); 
 if (serverTransactionId == null) 
 { 
 serverTransactionId = sipProvider.getNewServerTransaction(request); 
 callerDialog = serverTransactionId.getDialog(); 
 Response response = msgFactory.createResponse(Response.TRYING, request); 
 serverTransactionId.sendResponse(response); 
 } 
 //查询目标地址 
 URI reqUri = request.getRequestURI(); 
 URI contactURI = currUser.get(reqUri); 
 
 System.out.println("processInvite rqStr=" + reqUri + " contact=" + contactURI); 
 
 //根据Request uri来路由，后续的响应消息通过VIA来路由 
 Request cliReq = msgFactory.createRequest(request.toString()); 
 cliReq.setRequestURI(contactURI); 
 
 Via callerVia = (Via)request.getHeader(Via.NAME); 
 Via via = (Via) headerFactory.createViaHeader(ipAddr, port, "UDP", callerVia.getBranch()+"sipphone"); 
 
 // FIXME 需要测试是否能够通过设置VIA头域来修改VIA头域值 
 cliReq.removeHeader(Via.NAME); 
 cliReq.addHeader(via); 
 
 // 更新contact的地址 
 ContactHeader contactHeader = headerFactory.createContactHeader(); 
 Address address = addressFactory.createAddress("sip:sipsoft@" + ipAddr +":"+ port); 
 contactHeader.setAddress(address); 
 contactHeader.setExpires(3600); 
 cliReq.setHeader(contactHeader); 
 
 clientTransactionId = sipProvider.getNewClientTransaction(cliReq); 
 clientTransactionId.sendRequest(); 
 
 System.out.println("processInvite clientTransactionId=" + clientTransactionId.toString()); 
 
 System.out.println("send invite to callee: " + cliReq); 
 } 
 catch (TransactionUnavailableException e1) 
 { 
 // TODO Auto-generated catch block 
 e1.printStackTrace(); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (ParseException e) 
 { 
 e.printStackTrace(); 
 } 
 catch (Exception e) 
 { 
 e.printStackTrace(); 
 } 
 } 
 
 /** 
 * 处理SUBSCRIBE请求 
 * @param request 请求消息 
 */ 
 private void processSubscribe(Request request) 
 { 
 if (null == request) 
 { 
 System.out.println("processSubscribe request is null."); 
 return; 
 } 
 ServerTransaction serverTransactionId = null; 
 try 
 { 
 serverTransactionId = sipProvider.getNewServerTransaction(request); 
 } 
 catch (TransactionAlreadyExistsException e1) 
 { 
 // TODO Auto-generated catch block 
 e1.printStackTrace(); 
 } catch (TransactionUnavailableException e1) 
 { 
 // TODO Auto-generated catch block 
 e1.printStackTrace(); 
 } 
 
 try 
 { 
 Response response = null; 
 response = msgFactory.createResponse(200, request); 
 if (response != null) 
 { 
 ExpiresHeader expireHeader = headerFactory.createExpiresHeader(30); 
 response.setExpires(expireHeader); 
 } 
 System.out.println("response : " + response.toString()); 
 
 if(serverTransactionId != null) 
 { 
 serverTransactionId.sendResponse(response); 
 serverTransactionId.terminate(); 
 } 
 else 
 { 
 System.out.println("processRequest serverTransactionId is null."); 
 } 
 
 } 
 catch (ParseException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 } 
 /** 
 * 处理BYE请求 
 * @param request 请求消息 
 */ 
 private void processBye(Request request, RequestEvent requestEvent) 
 { 
 if (null == request || null == requestEvent) 
 { 
 System.out.println("processBye request is null."); 
 return; 
 } 
 Request byeReq = null; 
 Dialog dialog = requestEvent.getDialog(); 
 System.out.println("calleeDialog : " + calleeDialog); 
 System.out.println("callerDialog : " + callerDialog); 
 try 
 { 
 if (dialog.equals(calleeDialog)) 
 { 
 byeReq = callerDialog.createRequest(request.getMethod()); 
 ClientTransaction clientTran = sipProvider.getNewClientTransaction(byeReq); 
 callerDialog.sendRequest(clientTran); 
 calleeDialog.setApplicationData(requestEvent.getServerTransaction()); 
 } 
 else if (dialog.equals(callerDialog)) 
 { 
 byeReq = calleeDialog.createRequest(request.getMethod()); 
 ClientTransaction clientTran = sipProvider.getNewClientTransaction(byeReq); 
 calleeDialog.sendRequest(clientTran); 
 callerDialog.setApplicationData(requestEvent.getServerTransaction()); 
 } 
 else 
 { 
 System.out.println(""); 
 } 
 
 System.out.println("send bye to peer:" + byeReq.toString()); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 
 } 
 
 /** 
 * 处理CANCEL请求 
 * @param request 请求消息 
 */ 
 private void processCancel(Request request) 
 { 
 if (null == request) 
 { 
 System.out.println("processCancel request is null."); 
 return; 
 } 
 } 
 
 /** 
 * 处理INFO请求 
 * @param request 请求消息 
 */ 
 private void processInfo(Request request) 
 { 
 if (null == request) 
 { 
 System.out.println("processInfo request is null."); 
 return; 
 } 
 } 
 
 
 /** 
 * 处理ACK请求 
 * @param request 请求消息 
 */ 
 private void processAck(Request request, RequestEvent requestEvent) 
 { 
 if (null == request) 
 { 
 System.out.println("processAck request is null."); 
 return; 
 } 
 
 try 
 { 
 Request ackRequest = null; 
 CSeq csReq = (CSeq)request.getHeader(CSeq.NAME); 
 ackRequest = calleeDialog.createAck(csReq.getSeqNumber()); 
 calleeDialog.sendAck(ackRequest); 
 System.out.println("send ack to callee:" + ackRequest.toString()); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 
 
 } 
 
 /** 
 * 处理CANCEL消息 
 * @param request 
 * @param requestEvent 
 */ 
 private void processCancel(Request request, RequestEvent requestEvent) 
 { 
 // 判断参数是否有效 
 if (request == null || requestEvent == null) 
 { 
 System.out.println("processCancel input parameter invalid."); 
 return; 
 } 
 
 try 
 { 
 // 发送CANCEL 200 OK消息 
 Response response = msgFactory.createResponse(Response.OK, request); 
 ServerTransaction cancelServTran = requestEvent.getServerTransaction(); 
 if (cancelServTran == null) 
 { 
 cancelServTran = sipProvider.getNewServerTransaction(request); 
 } 
 cancelServTran.sendResponse(response); 
 
 // 向对端发送CANCEL消息 
 Request cancelReq = null; 
 Request inviteReq = clientTransactionId.getRequest(); 
 List list = new ArrayList(); 
 Via viaHeader = (Via)inviteReq.getHeader(Via.NAME); 
 list.add(viaHeader); 
 
 CSeq cseq = (CSeq)inviteReq.getHeader(CSeq.NAME); 
 CSeq cancelCSeq = (CSeq)headerFactory.createCSeqHeader(cseq.getSeqNumber(), Request.CANCEL); 
 cancelReq = msgFactory.createRequest(inviteReq.getRequestURI(), 
 inviteReq.getMethod(), 
 (CallIdHeader)inviteReq.getHeader(CallIdHeader.NAME), 
 cancelCSeq, 
 (FromHeader)inviteReq.getHeader(From.NAME), 
 (ToHeader)inviteReq.getHeader(ToHeader.NAME), 
 list, 
 (MaxForwardsHeader)inviteReq.getHeader(MaxForwardsHeader.NAME)); 
 ClientTransaction cancelClientTran = sipProvider.getNewClientTransaction(cancelReq); 
 cancelClientTran.sendRequest(); 
 } 
 catch (ParseException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (TransactionAlreadyExistsException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (TransactionUnavailableException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 } 
 
 
 private ServerTransaction serverTransactionId = null; 
 /* (non-Javadoc) 
 * @see javax.sip.SipListener#processRequest(javax.sip.RequestEvent) 
 */ 
 public void processRequest(RequestEvent arg0) 
 { 
 Request request = arg0.getRequest(); 
 if (null == request) 
 { 
 System.out.println("processRequest request is null."); 
 return; 
 } 
 System.out.println("processRequest:" + request.toString()); 
 if (Request.INVITE.equals(request.getMethod())) 
 { 
 processInvite(request, arg0); 
 } 
 else if (Request.REGISTER.equals(request.getMethod())) 
 { 
 processRegister(request, arg0); 
 } 
 else if (Request.SUBSCRIBE.equals(request.getMethod())) 
 { 
 processSubscribe(request); 
 } 
 else if (Request.ACK.equalsIgnoreCase(request.getMethod())) 
 { 
 processAck(request, arg0); 
 } 
 else if (Request.BYE.equalsIgnoreCase(request.getMethod())) 
 { 
 processBye(request, arg0); 
 } 
 else if (Request.CANCEL.equalsIgnoreCase(request.getMethod())) 
 { 
 processCancel(request, arg0); 
 } 
 else 
 { 
 System.out.println("no support the method!"); 
 } 
 }

/** 
 * 主叫对话 
 */ 
 private Dialog calleeDialog = null; 
 
 /** 
 * 被叫对话 
 */ 
 private Dialog callerDialog = null; 
 
 /** 
 * 
 */ 
 ClientTransaction clientTransactionId = null; 
 
 /** 
 * 处理BYE响应消息 
 * @param reponseEvent 
 */ 
 private void doByeResponse(Response response, ResponseEvent responseEvent) 
 { 
 Dialog dialog = responseEvent.getDialog(); 
 
 try 
 { 
 Response byeResp = null; 
 if (callerDialog.equals(dialog)) 
 { 
 ServerTransaction servTran = (ServerTransaction)calleeDialog.getApplicationData(); 
 byeResp = msgFactory.createResponse(response.getStatusCode(), servTran.getRequest()); 
 servTran.sendResponse(byeResp); 
 } 
 else if (calleeDialog.equals(dialog)) 
 { 
 ServerTransaction servTran = (ServerTransaction)callerDialog.getApplicationData(); 
 byeResp = msgFactory.createResponse(response.getStatusCode(), servTran.getRequest()); 
 servTran.sendResponse(byeResp); 
 } 
 else 
 { 
 
 } 
 System.out.println("send bye response to peer:" + byeResp.toString()); 
 } 
 catch (ParseException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 } 
 /* (non-Javadoc) 
 * @see javax.sip.SipListener#processResponse(javax.sip.ResponseEvent) 
 * 
 */ 
 public void processResponse(ResponseEvent arg0) 
 { 
 // FIXME 需要判断各个响应对应的是什么请求 
 Response response = arg0.getResponse(); 
 
 System.out.println("recv the response :" + response.toString()); 
 System.out.println("respone to request : " + arg0.getClientTransaction().getRequest()); 
 
 if (response.getStatusCode() == Response.TRYING) 
 { 
 System.out.println("The response is 100 response."); 
 return; 
 } 
 
 try 
 { 
 ClientTransaction clientTran = (ClientTransaction) arg0.getClientTransaction(); 
 
 if (Request.INVITE.equalsIgnoreCase(clientTran.getRequest().getMethod())) 
 { 
 int statusCode = response.getStatusCode(); 
 Response callerResp = null; 
 
 callerResp = msgFactory.createResponse(statusCode, serverTransactionId.getRequest()); 
 
 // 更新contact头域值，因为后面的消息是根据该URI来路由的 
 ContactHeader contactHeader = headerFactory.createContactHeader(); 
 Address address = addressFactory.createAddress("sip:sipsoft@"+ipAddr+":"+port); 
 contactHeader.setAddress(address); 
 contactHeader.setExpires(3600); 
 callerResp.addHeader(contactHeader); 
 
 // 拷贝to头域 
 ToHeader toHeader = (ToHeader)response.getHeader(ToHeader.NAME); 
 callerResp.setHeader(toHeader); 
 
 // 拷贝相应的消息体 
 ContentLength contentLen = (ContentLength)response.getContentLength(); 
 if (contentLen != null &amp;&amp; contentLen.getContentLength() != 0) 
 { 
 ContentType contentType = (ContentType)response.getHeader(ContentType.NAME); 
 System.out.println("the sdp contenttype is " + contentType); 
 
 callerResp.setContentLength(contentLen); 
 //callerResp.addHeader(contentType); 
 callerResp.setContent(response.getContent(), contentType); 
 } 
 else 
 { 
 System.out.println("sdp is null."); 
 } 
 if (serverTransactionId != null) 
 { 
 callerDialog = serverTransactionId.getDialog(); 
 calleeDialog = clientTran.getDialog(); 
 serverTransactionId.sendResponse(callerResp); 
 System.out.println("callerDialog=" + callerDialog); 
 System.out.println("serverTransactionId.branch=" + serverTransactionId.getBranchId()); 
 } 
 else 
 { 
 System.out.println("serverTransactionId is null."); 
 } 
 
 System.out.println("send response to caller : " + callerResp.toString()); 
 } 
 else if (Request.BYE.equalsIgnoreCase(clientTran.getRequest().getMethod())) 
 { 
 doByeResponse(response, arg0); 
 } 
 else if (Request.CANCEL.equalsIgnoreCase(clientTran.getRequest().getMethod())) 
 { 
 //doCancelResponse(response, arg0); 
 } 
 else 
 { 
 
 } 
 
 
 } 
 catch (ParseException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (Exception ex) 
 { 
 ex.printStackTrace(); 
 } 
 
 } 
 
 private void doCancelResponse(Response response, ResponseEvent responseEvent) 
 { 
 //FIXME 需要验证参数的有效性 
 ServerTransaction servTran = (ServerTransaction)callerDialog.getApplicationData(); 
 Response cancelResp; 
 try 
 { 
 cancelResp = msgFactory.createResponse(response.getStatusCode(), servTran.getRequest()); 
 servTran.sendResponse(cancelResp); 
 } 
 catch (ParseException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (SipException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 catch (InvalidArgumentException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 } 
 
 } 
 public void processTimeout(TimeoutEvent arg0) 
 { 
 // TODO Auto-generated method stub 
 System.out.println(" processTimeout " + arg0.toString()); 
 } 
 public void processTransactionTerminated(TransactionTerminatedEvent arg0) { 
 // TODO Auto-generated method stub 
 System.out.println(" processTransactionTerminated " + arg0.getClientTransaction().getBranchId() 
 + " " + arg0.getServerTransaction().getBranchId()); 
 } 
 
 private static SipStack sipStack = null; 
 
 private static AddressFactory addressFactory = null; 
 
 private static MessageFactory msgFactory = null; 
 
 private static HeaderFactory headerFactory = null; 
 
 private static SipProvider sipProvider = null; 
 
 private void init() 
 { 
 SipFactory sipFactory = null; 
 
 sipFactory = SipFactory.getInstance(); 
 if (null == sipFactory) 
 { 
 System.out.println("init sipFactory is null."); 
 return; 
 } 
 
 sipFactory.setPathName("gov.nist"); 
 Properties properties = new Properties(); 
 properties.setProperty("javax.sip.STACK_NAME", "sipphone"); 
 // You need 16 for logging traces. 32 for debug + traces. 
 // Your code will limp at 32 but it is best for debugging. 
 properties.setProperty("gov.nist.javax.sip.TRACE_LEVEL", "32"); 
 properties.setProperty("gov.nist.javax.sip.DEBUG_LOG", 
 "sipphonedebug.txt"); 
 properties.setProperty("gov.nist.javax.sip.SERVER_LOG", 
 "sipphonelog.txt"); 
 try 
 { 
 sipStack = sipFactory.createSipStack(properties); 
 } 
 catch (PeerUnavailableException e) 
 { 
 // TODO Auto-generated catch block 
 e.printStackTrace(); 
 return; 
 } 
 
 try 
 { 
 headerFactory = sipFactory.createHeaderFactory(); 
 addressFactory = sipFactory.createAddressFactory(); 
 msgFactory = sipFactory.createMessageFactory(); 
 ListeningPoint lp = sipStack.createListeningPoint("192.168.0.20", 
 5060, "udp"); 
 SipPhone listener = this; 
 
 sipProvider = sipStack.createSipProvider(lp); 
 System.out.println("udp provider " + sipProvider.toString()); 
 sipProvider.addSipListener(listener); 
 } 
 catch (Exception ex) 
 { 
 ex.printStackTrace(); 
 return; 
 } 
 
 } 
 
 /** 
 * 程序入口 
 * @param args 
 */ 
 public static void main(String []args) 
 { 
 new SipPhone().init(); 
 } 
 
}</pre> </td> 
 </tr> 
 </tbody> 
</table>