I have a 504g registered to two different SIP servers and accounts. Line Key 1 is Server A, Line Key 2 is Server B. Both are Asterisk servers but in two totally different locations with two different sets of auth credentials.
I wanted to use Line Key 4 for BLF to show when a particular extension is in use on Server B. I configured the Line Key 4 as Disabled, Private, and Extended Function to fnc=blf;sub=myexten@serverB.com;ext=myexten@serverB.com (the Admin guide is terrible and doesn't really define what 'sub' and 'ext' mean related to what gets sent to the server.)
The problem is when the 504g sends the SUBSCRIBE message to subscribe to the BLF events, it's setting the Contact: to that of the user configured for Server A (the one registered on Line 1) and not Server B. So it of course tries to auth with Server A's credentials but to Server B, and fails with an amber light -- and for the life of me I cannot figure out how to get the thing to auth with the right account info. Does it just arbitrarily use the first configured line's credentials with no way to choose? And if so, how useful is that?
I can get BLF to work on Server A obviously since it subscribes with the credentials in that case.
