[SIPForum-discussion] Issue to use Tag

[NK]

Hi Kareena,

In the word of Hairpinining.

Hairpinning is when a user agent makes a call to itself, mainly for the
purposes of self-testing. (The other reason you might have this is because
your proxy routes your call to yourself, called "tromboning". When done
intentionally, it's a useful end-to-end test of your infrastructure.)

Assume you send an INVITE to yourself, and answer it. Your user agent must
then have two dialogs (each with identifiers), each representing one end of
the call. If you only have a Call-ID, then you don't know which dialog is
the caller and which the callee.

The FROM and TO tags here are the way you can unambiguously determine which
dialog is which.

Hope the explanation helps.

Thanks,

Nitin Kapoor
On Wed, Sep 26, 2012 at 2:28 AM, Kareena K <kareenaf1 at gmail.com> wrote:

> Hi all,
>
> why tag(i.e to-tag and from-tag) had been used if we can identity the call
> by using Call-id.
>
>
>
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