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<P style="BACKGROUND: white"><SPAN lang=EN-US style="FONT-SIZE: 8.5pt; COLOR: #444444; FONT-FAMILY: Verdana"><FONT face="Times New Roman, Times, Serif"><FONT size=3>In my case, almost all NAT will not allow the RTP packet pass-through. I do believe that the NAT(router) actually don¡¯t know where the packet should send to. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p></FONT></FONT></SPAN></P>
<P style="BACKGROUND: white"><SPAN lang=EN-US style="FONT-SIZE: 8.5pt; COLOR: #444444; FONT-FAMILY: Verdana"><FONT face="Times New Roman, Times, Serif"><FONT size=3>Before the server(S) sent the RTP packet to the client(C) , S-C only have a TCP connection for RTSP. The NAT (router) can¡¯t read the RTSP (application layer). Therefore, it will not do everything else to help the RTP. <SPAN style="mso-spacerun: yes"> </SPAN>In this case, all the RTSP runs OK but nothing on RTP can be received.<o:p></o:p></FONT></FONT></SPAN></P>
<P style="BACKGROUND: white"><SPAN lang=EN-US style="FONT-SIZE: 8.5pt; COLOR: #444444; FONT-FAMILY: Verdana"><o:p><FONT face="Times New Roman, Times, Serif" size=3> </FONT></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-US><FONT face="Times New Roman, Times, Serif" color=#000000 size=3>Solutions:</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; mso-list: l0 level1 lfo1; tab-stops: list 18.0pt"><FONT face="Times New Roman, Times, Serif"><FONT size=3><SPAN lang=EN-US style="mso-fareast-font-family: 'Times New Roman'"><SPAN style="mso-list: Ignore"><FONT color=#000000>1)<SPAN style="FONT: 7pt 'Times New Roman'"> </SPAN></FONT></SPAN></SPAN><SPAN lang=EN-US><FONT color=#000000>If you have access to the NAT device, the port ¡°forwarding¡± can help. A pair of RTP/RTCP port in your client had to be fixed first and set the port-forwarding in the NAT. </FONT></SPAN></FONT></FONT></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; mso-list: l0 level1 lfo1; tab-stops: list 18.0pt"><FONT face="Times New Roman, Times, Serif"><FONT size=3><SPAN lang=EN-US style="mso-fareast-font-family: 'Times New Roman'"><SPAN style="mso-list: Ignore"><FONT color=#000000>2)<SPAN style="FONT: 7pt 'Times New Roman'"> </SPAN></FONT></SPAN></SPAN><SPAN lang=EN-US><FONT color=#000000>If only one client is needed to receive the RTP packet, the client can put in DMZ. ( all port forwarded to the PC(Client) in the DMZ)</FONT></SPAN></FONT></FONT></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; mso-list: l0 level1 lfo1; tab-stops: list 18.0pt"><FONT face="Times New Roman, Times, Serif"><FONT size=3><SPAN lang=EN-US style="mso-fareast-font-family: 'Times New Roman'"><SPAN style="mso-list: Ignore"><FONT color=#000000>3)<SPAN style="FONT: 7pt 'Times New Roman'"> </SPAN></FONT></SPAN></SPAN><SPAN lang=EN-US><FONT color=#000000>According to the RFC 3550, it has mentioned an item called ¡°translator¡±. it can help to connect the S-C in the firewall or NAT protected environment. I think it have to read the RTSP information and create a tunnel for those blocked incoming RTP/RTCP (S->C). </FONT></SPAN></FONT></FONT></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-US><FONT face="Times New Roman, Times, Serif" color=#000000 size=3>Actually, I am not 100% sure what the translator is. I know what it should do but not know how it works and how to construct or any open-source is available in the world. I am working on right now. By using this Translator, I do believe that a technique called ¡°Hole Punching¡± would help. If ¡°Hole Punching¡± used as a keyword, Tons of documents can be found in the web. </FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-US><o:p><FONT face="Times New Roman, Times, Serif" color=#000000 size=3> </FONT></o:p></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-US><FONT face="Times New Roman, Times, Serif" color=#000000 size=3>Hope it information may help.</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-US><FONT face="Times New Roman" color=#000000 size=3></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-US><FONT face="Times New Roman" color=#000000 size=3>KL Fung</FONT></SPAN></P>
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<BR>> ----------------------------------------------------------------------<BR>> <BR>> Message: 1<BR>> Date: Mon, 3 Mar 2008 17:13:31 -0600<BR>> From: xcsmith@rockwellcollins.com<BR>> Subject: Re: [Live-devel] A network problem<BR>> To: LIVE555 Streaming Media - development & use<BR>> <live-devel@ns.live555.com><BR>> Message-ID:<BR>> <OF2C2943F0.2787B92F-ON86257401.007E23EF-86257401.007FF8FA@rockwellcollins.com><BR>> <BR>> Content-Type: text/plain; charset="us-ascii"<BR>> <BR>> > In general, you cannot expect RTSP/RTP to work over a NAT. However,<BR>> > because your server is really on the Internet, then you might be <BR>> > able to get RTP-over-TCP streaming to work, even though your client <BR>> > is not really on the Internet.<BR>> <BR>> Is the IP address the only problem with NAT? Couldn't routers with <BR>> correct port forwarding (on either end of the RTSP connection) take care <BR>> of this?<BR>> Also, I notice a lot of posts about UDP transfer problems. Is the primary <BR>> reason that firewalls are often blocking UDP? RFC 2326 1.4 Claims that <BR>> passing the Transport Initialization Information in the RTSP messages <BR>> allows routers to open the firewall as necessary. Do any commercially <BR>> available routers/firewalls actually allow this for RTP? Based on posts <BR>> so far, it sounds like if you have a firewall, you're SOL without <BR>> RTP-Over-TCP.<BR>> <BR>> RFC 2326, Section 1.4 Protocol Properties<BR>> " Proxy and firewall friendly:<BR>> The protocol should be readily handled by both application and<BR>> transport-layer (SOCKS [14]) firewalls. A firewall may need to<BR>> understand the SETUP method to open a "hole" for the UDP media<BR>> stream."<BR>> -------------- next part --------------<BR>> An HTML attachment was scrubbed...<BR>> URL: http://lists.live555.com/pipermail/live-devel/attachments/20080303/500863a8/attachment-0001.html <BR>> <BR><BR><BR></P></body>
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