This draft is currently blocking on a number of other items. The authors are aware that many changes are needed to the draft, but until these other items are unblocked the draft is unlikely to get much attention.
thanks,
-rohan
On Thursday, December 12, 2002, at 09:36 PM, Rahul Gulati wrote:
Hi, All,
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I am again reposting this query as I didnt get reply to the previous one.
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From draft-ietf-sipping-nat-scenarios-00, page 47-48:
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In the example configuration shown in Figure 22, the signaling path is established when the SIP UA's register with the corresponding� Proxy/Register (Signaling server). *The SIP REGISTER message contains� an extension tag carried in the Proxy-Require header, indicating to� the Proxy that the client is behind a NAT* (Note: the client or the Proxy does not care about the type of NAT, as the same solution applies to all types). This packet is NAT-ed by the Enterprise NAT with a new source IP address and port. If the Proxy supports the extension tag, it creates an association between the IP address and port from which the packet arrived and the actual address of the user. The response to the Registration message is sent to this IP address and port (not to the Contact address in the REGISTER).
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My question here is :
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*Why do we need this extension tag?*
--We can know if a�UA is behind the NAT by verifying if the Src IP address ( NATed incase of NAT ) is the same as the IP address mentioned in the Contact header of the REGISTER message.
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Best Regards'
Rahul
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