Barry Desborough wrote:
>
> Opinions please:-
>
> The From: header -
> Is it acceptable, useful, and/or necessary to specify a registered
> address-of-record in the From: header of an outgoing INVITE from a UA? I
> have received a request from another implementer to modify my UA code to do
> this so that he can use my From: header to determine my address-of-record in
> order to call me back. Any other ideas about how to achieve this if the
> proposed usage of the From: header is unacceptable?
The address in From should be an address that's acceptable for callbacks
(assuming you want to be called back). However, normally, that will be a
proxy-based address, such as [EMAIL PROTECTED], rather than your IP
address or host name.
>
> The Call-ID: header -
> With the change in syntax from localid"@"host to token["@"token], how is the
> requirement for global uniqueness met? For example, if two identically
> implemented UA's are communicating using the newer form, isn't it possible
> that two indistinguishable call legs could be created, one by each UA?
Even identically implemented hosts must choose sufficiently long random
identifiers so that collision is extremely unlikely. You certainly
cannot just choose a counter. There are numerous ways to pick random
identifiers, e.g., based on IP addresses, MAC addresses, time of day,
host name, etc.. See RFC 1750 for hints.
>
> Barry
> Barry Desborough
>
> Mailto:[EMAIL PROTECTED]
> +44 1344 784 907
>
> http://www.VegaStream.com
--
Henning Schulzrinne http://www.cs.columbia.edu/~hgs
