[Serusers] 305 Use Proxy

[Rick van Rein]

Hello,

	(Nils: Thanks for your helpful reply.)

> unfortunately the usage of 305 is totally under specified. And I haven't
> it being used in the field ever. Anybody else maybe?

There are good reasons for using it though.  For me, these are:

1. I want to pass off any POTS calls to upstream SIP providers without
   having to worry about RTP proxies (setting them up, or wondering if
   they would be needed at all).  If traffic goes through an outside-NAT
   proxy, the sip2pots provider would probably decide no RTP proxy is
   needed.

2. I want to avoid being responsible for the traffic that I pass on.
   This means that I can be a proxy to unregistered users, if they like.
   It makes it very easy for them to try out a service if they only have
   to set the "proxy" field in their phone.

I understand that all this reasoning won't help to improve the RFC, as this
is not the task of the people on this list.  I just wanted to clear up why
this is useful (to me at least).


Thanks,
 -Rick