[Asterisk-Users] What's the purpose of the "username=" line?

[telephony at jonjay.com]

After some experimentation and posting, I have concluded
that in the file sip.conf, the line:

username = irrelevant

has no effect whatsoever on SIP registration.  Any entry on
the right hand side will make no difference, and the line can even
be avoided altogether (as the O'Reilly book example does).

The only effect of that line that have I found is to be displayed
under the output of the

host*CLI> sip show peers

command.

So, what is that line good for?

TIA,

-Ramon F Herrera