SIP - register before send/receive?

Hello,

I'm using SIP on Nokia mobile phones in Java...

Do you i have to register every time a user before sending
or receiving any
messages?

>From the nokia SIP examples i still haven't understood
how receiving works.
Seems like all examples are listening on a port for all
messages and not
only message which are addressed to the user with should
receive them.

I understand that

sip;type=\&qu
ot;application/test\"

means for me, that the SipServer-Listener-implementation is
listening for
all messages which belong to the application 'test'.

Ok, let's say i have several users and i don't want all
messages but only
the message which belong to me.

How do i realize that? How do I let the sip server know that
I'm user
"user2" and want only messages from
"user1".

BR, Sebastian


_______________________________________________
Sip mailing list  https://ww
w1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use sip-implementorscs.columbia.edu for questions on current
sip
Use sippingietf.org for new developments on the application of
sip