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[Serusers] STUN and (Media/RTP)Proxy

[Serusers] How does t_relay()...

[Serusers] CIsco AS5300 X SER

info＠beeplove.com

31 Mar 2005 31 Mar '05

9:59 p.m.

If a client come through STUN and behind NAT, SER dont need to do anything to handle NAT. correct me pls, if I am wrong. How ser will figure it out that whether a client is coming through STUN or not? Thanks, Mohammad -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ .

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Klaus Darilion

1 Apr 1 Apr

10:40 a.m.

The client will use STUN to detect the type of NAT (coned, symmetric ...) and the public IP address:port. If the NAT device can be traversed by means of STUN, then the client uses the public IP address and port in the SIP messages (Via: header, Contact: header, SDP, ...). If the NAT device can't traversed by use of STUN (symmetric NAT), the client has to behave dumb and does not use the public addresses. Thus, it uses its private IP address:port (e.g. 192.168.0.2:5060) in the SIP messages. In ser, you will use nat_uac_test() to test the incoming messages. You can test for private IP addresses in the various headers (Via, Contact, SDP) and compare the Via: header with the IP-address:port the message is coming from. If the client uses STUN and public IP address:port in the SIP message, ser can not detect if the client is behind NAT. Thus, ser does not NAT traversal - as it should be, because the client das NAT traversal itself. If the nat_uac_test detects that the SIP messages comes from a natted client, then you have to use the various functions (force_contact, nated_register, force_rtpproxy...) to rewrite the SIP messages. regards, klaus PS: read the README from the nathelper module and the mediaproxy module. You have to choose either nathelper-module+rtpproxy or the mediaproxy-module+mediaproxy (from ag-projects). info(a)beeplove.com wrote:

If a client come through STUN and behind NAT, SER dont need to do anything to handle NAT. correct me pls, if I am wrong. How ser will figure it out that whether a client is coming through STUN or not? Thanks, Mohammad -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ . _______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers

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Greger V. Teigre

12:57 p.m.

The Getting Started document found at http://onsip.org/ has a thorough walkthrough of NATing with examples for mediaproxy and rtpproxy. g-) Klaus Darilion wrote:

The client will use STUN to detect the type of NAT (coned, symmetric ...) and the public IP address:port. If the NAT device can be traversed by means of STUN, then the client uses the public IP address and port in the SIP messages (Via: header, Contact: header, SDP, ...). If the NAT device can't traversed by use of STUN (symmetric NAT), the client has to behave dumb and does not use the public addresses. Thus, it uses its private IP address:port (e.g. 192.168.0.2:5060) in the SIP messages. In ser, you will use nat_uac_test() to test the incoming messages. You can test for private IP addresses in the various headers (Via, Contact, SDP) and compare the Via: header with the IP-address:port the message is coming from. If the client uses STUN and public IP address:port in the SIP message, ser can not detect if the client is behind NAT. Thus, ser does not NAT traversal - as it should be, because the client das NAT traversal itself. If the nat_uac_test detects that the SIP messages comes from a natted client, then you have to use the various functions (force_contact, nated_register, force_rtpproxy...) to rewrite the SIP messages. regards, klaus PS: read the README from the nathelper module and the mediaproxy module. You have to choose either nathelper-module+rtpproxy or the mediaproxy-module+mediaproxy (from ag-projects). info(a)beeplove.com wrote:

If a client come through STUN and behind NAT, SER dont need to do anything to handle NAT. correct me pls, if I am wrong. How ser will figure it out that whether a client is coming through STUN or not? Thanks, Mohammad -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ . _______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers

_______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers

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Mohammad Khan

2 Apr 2 Apr

4:52 p.m.

Kaaus, thansk for replying me. One more question regarding this issue, Say for example: 1. A UA is behind Symmetric NAT and its using STUN. 2. If SER use nat_uac_test(3), it will return true, right? 3. If UA is behind other types of NAT, would nat_uac_test(3) still return true? My question is, If a UA use STUN, SER dont need to do anything for NAT for first three types of NAT. Is nat_uac_test return false for first three types of NAT? Thanks again, Mohammad Klaus Darilion wrote:

The client will use STUN to detect the type of NAT (coned, symmetric ...) and the public IP address:port. If the NAT device can be traversed by means of STUN, then the client uses the public IP address and port in the SIP messages (Via: header, Contact: header, SDP, ...). If the NAT device can't traversed by use of STUN (symmetric NAT), the client has to behave dumb and does not use the public addresses. Thus, it uses its private IP address:port (e.g. 192.168.0.2:5060) in the SIP messages. In ser, you will use nat_uac_test() to test the incoming messages. You can test for private IP addresses in the various headers (Via, Contact, SDP) and compare the Via: header with the IP-address:port the message is coming from. If the client uses STUN and public IP address:port in the SIP message, ser can not detect if the client is behind NAT. Thus, ser does not NAT traversal - as it should be, because the client das NAT traversal itself. If the nat_uac_test detects that the SIP messages comes from a natted client, then you have to use the various functions (force_contact, nated_register, force_rtpproxy...) to rewrite the SIP messages. regards, klaus PS: read the README from the nathelper module and the mediaproxy module. You have to choose either nathelper-module+rtpproxy or the mediaproxy-module+mediaproxy (from ag-projects). info(a)beeplove.com wrote:

If a client come through STUN and behind NAT, SER dont need to do anything to handle NAT. correct me pls, if I am wrong. How ser will figure it out that whether a client is coming through STUN or not? Thanks, Mohammad -------------------------------------------------------------------- mail2web - Check your email from the web at http://mail2web.com/ . _______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers

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Greger V. Teigre
info＠beeplove.com
Klaus Darilion
Mohammad Khan