[SR-Users] authcheck and fd variable

[Robert Lieback]

Hello,

i'm looking into kamalio (btw: thanks to asipto for the great book) and 
i hope someone can push me in the right direction. I have a 
question/problem with some lines in the default config (kamailio.cfg) 
around line 754:

    ...

    if (is_method("REGISTER") || from_uri==myself) {
             # authenticate requests
             if (!auth_check("$fd", "subscriber", "1")) {
                 auth_challenge("$fd", "0");
                 exit;
             }

    ...

auth_check() and auth_challenge doesn't work, but i've provided the 
correct credentials. When i replace "$fd" with domain "voip.XXXXXX.de" 
it works. This domain is also defined as alias in the config and all sip 
messages i send to the server have a correct from header with this domain.
First step for me would be to look whats stored in $fd, but how can i 
output the content of $fd? Cause log(2, "$fd") or xlog("$fd") doesn't 
work and throws errors about unknown variables.

Thanks,

Robert Lieback