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<DIV><FONT face=Arial size=2>Hernan,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>OSP uses Public key based authentication and encrytion schemes, which are stronger than Radius's shared secrets. If you use OSP for authentication and authorization, you need not use Radius. OSP, just like Radius, has a client stack, which is implemented in the SER, and has a Server, which provides centralized call routing, accounting, and security. At the time of startup, the OSP server and the client, the SER in this case, exchange their public keys. The public and private keys can then be used to encode/decode messages as desired. </FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>A typical call setup procedure looks like this</FONT></DIV>
<DIV><FONT face=Arial size=2>1. The source SER goes to the osp server to get the SIP URI corresopnding to the destination. The message is encoded using the source SER's private key.</FONT></DIV>
<DIV><FONT face=Arial size=2>2. The osp server decodes the message using source SERs public key and after successful decoding (authentication) returns the route back to the source. Along with the route, it also sends back a digitally signed (using the OSP Servers private key) token.</FONT></DIV>
<DIV><FONT face=Arial size=2>3. The Source uses the route returned by the OSP Srver to send an INVITE. The INVITE message contains the token issued by the OSP Server </FONT></DIV>
<DIV><FONT face=Arial size=2>4. The destination decodes/validates the token using the OSP Servers public key. Upon successful validation (authorization) it accepts the call. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>This saves you the effort of mantaining cumbersome access lists for authentication. I can provide you with more documentatin on OSP and how to </FONT></DIV>
<DIV><FONT face=Arial size=2>use SER with OSP if you wish</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV><FONT face=Verdana size=2>
<DIV>Thanks,</DIV>
<DIV>Vikrant</DIV>
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<DIV>Fogive my ignorance for I have never heard of OSP before ;) You mentioned Radius in your message. How does Radius authentication work in OSP? I am having a tough time getting mine to work. </DIV>
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<DIV>hernan<BR><BR><B><I>vmathur@transnexus.com</I></B> wrote:</DIV>
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<DIV><FONT face=Verdana size=2><FONT face=Arial>Dear All,</FONT></FONT></DIV>
<DIV><FONT face=Verdana size=2><FONT face=Arial></FONT></FONT> </DIV>
<DIV><FONT face=Verdana size=2><FONT face=Arial>I have recently implemented OSP w/ SER. OSP is an ETSI defined protocol, which I am using for ceneralised routing, and security of my inter-domain calls. The problem, however, is that the build process is a little lengthy. I want to contribute my implementation to this group so that anyone who is struggling with SER routing configurations or Radius authentication issues may benefit from it. I was, thus, wondering if we can have a binary file of the OSP enabled SER, that can be distributed with the source code. Does anyone have an opinion on this? </FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Also, for anyone who wants to check-out this implementation, I can provide more details.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Thanks,</FONT></DIV>
<DIV><FONT face=Arial>Vikrant</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV></FONT><FONT face="Times New Roman" size=3>_______________________________________________<BR>Serusers mailing list<BR>serusers@lists.iptel.org<BR>http://lists.iptel.org/mailman/listinfo/serusers</FONT><BR></BLOCKQUOTE></FONT></DIV></body></html>