[SR-Users] Kamailio example configuration: auth section incomplete?

Hello again, Still getting familiar with kamailio, and I'm wondering about the AUTH route in the example configuration file. Here's a reducted-simplified version of it for reference (from git master, without IP AUTH and comments): ______________________________________________ route[AUTH] { if (is_method("REGISTER") || from_uri==myself) { if (!auth_check("$fd", "subscriber", "1")) { auth_challenge("$fd", "0"); exit; } if(!is_method("REGISTER|PUBLISH")) consume_credentials(); } if (from_uri!=myself && uri!=myself) { sl_send_reply("403","Not relaying"); exit; } return; } ______________________________________________ So the way I see it, what happens is the following: * All REGISTERs will be challenged * All SIP messages with kamailio's aliases in the "From" header URI will be challenged * All SIP messages with no reference to kamailio's aliases in both R-URI and "From" header URI will be dropped The question is, what about messages that do not enter either of the two conditionals? For example, I expect the following to be very common: * Method: INVITE * R-URI: myself * From: username@"UAC's local IP address" (not myself) * To: myself So in the example above, the auth route will return without either having challenged or dropped the request, am I correct? This is because: * For the challenge: Method is not REGISTER and "From URI" is not one of kamailio host's aliases (cumulatively) * For dropping after sending 403: "From URI" is not one of kamailio's host's aliases (which calculates to true) but R-URI is "myself" So I'm guessing we're expecting the challenge to come from elsewhere in cases like the example above? Or is there something else I'm missing here? Thanks! BR, George