How do two sip server Migration presence?

[bruceday2007]

How do two sip server Migration presence? Two sip server is ims.nsn.com and gz.nsn.com.
what i send form one sip server like this:

SUBSCRIBE sip:bruce@ims.nsn.com SIP/2.0
To: "bruce" <sip:bruce@ims.nsn.com>;contacts=presence;tag=2449
Contact: <sip:192.168.2.104:5060;transport=udp;wlsscid=1ae4479ac6ff71;appsessionid=app-teq252rjm2dm>
CSeq: 1 SUBSCRIBE
Supported: eventlist
Call-ID: wlss-14eac52a-777a00f5a89c879bd48ea10fb76d303f@192.168.2.104
Event: presence
Via: SIP/2.0/UDP 192.168.2.104:5060;wlsscid=1ae4479ac6ff71;branch=z9hG4bK0759a95a8f65ae0621d81b33137b0526
From: "bruce01" <sip:bruce01@gz.nsn.com>;tag=46bd9a2d
Expires: 3600
Max-Forwards: 70
Content-Length: 0

and i get 404 error.

[bruceday2007]

two users logined each sip server.

[wizard_hu_]

404 is a pretty old and well-known error code. Do those two SIP servers know about each other?