Re: [reSIProcate-users] does 183 must have contact header?

[Adam Roach <adam@xxxxxxxxxxx>]

maodong hu wrote:
> hi, scott
>
> somebody told me RFC 3261 is not requiring the contact header to be 
> present in 1xx responses
>
> can you help to confirm is it correct or not?

You are correct -- "Contact" is not required in provisional responses 
(see Table 2 in RFC 3261).

However, provisional responses without a "Contact" don't create a dialog.

/a