Similar stuff happens with SOFIA base sip endpoint (Nokia N900 cell phone, integrated sip client) - only difference that it has registration expiration MUCH shorted than CISCO/LinkSys SPA942 - business class telephone. Since it's behind NAT - contact line differs, so only one instance will be contacted. I suppose If I will use it with no NAT it will be the same as for SPA942. Anyway that stuff is not critical in any sence. freeswitch@default> sofia_contact sip3779100 sofia/internal/sip:sip3779100@192.168.1.78:62216;transport=udp;fs_nat=yes;fs_path=sip%3Asip3779100%40192.168.1.78%3A62216%3Btransport%3Dudp,sofia/internal/sip:sip3779100@192.168.1.78:57180;transport=udp;fs_nat=yes;fs_path=sip%3Asip3779100%40192.168.1.78%3A57180%3Btransport%3Dudp freeswitch@default> Registrations: ================================================================================================= Call-ID: b48531de-fcf9-122e-f08a-5c57c8780000 User: sip3779100@192.168.100.11 Contact: "user" <sip:sip3779100@192.168.1.78:57180;transport=udp;fs_nat=yes;fs_path=sip%3Asip3779100%40192.168.1.78%3A57180%3Btransport%3Dudp> Agent: Telepathy-SofiaSIP/0.6.2 sofia-sip/1.12.10devel Status: Registered(UDP-NAT)(unknown) EXP(2011-05-20 01:31:22) EXPSECS(40) Host: lab3 IP: 192.168.1.78 Port: 57180 Auth-User: sip3779100 Auth-Realm: 192.168.100.11 MWI-Account: sip3779100@192.168.100.11 Call-ID: 07021fba-fcfa-122e-7e8d-5c57c8780000 User: sip3779100@192.168.100.11 Contact: "user" <sip:sip3779100@192.168.1.78:49438;transport=udp;fs_nat=yes;fs_path=sip%3Asip3779100%40192.168.1.78%3A49438%3Btransport%3Dudp> Agent: Telepathy-SofiaSIP/0.6.2 sofia-sip/1.12.10devel Status: Registered(UDP-NAT)(unknown) EXP(2011-05-20 01:32:03) EXPSECS(81) Host: lab3 IP: 192.168.1.78 Port: 49438 Auth-User: sip3779100 Auth-Realm: 192.168.100.11 MWI-Account: sip3779100@192.168.100.11 Total items returned: 2 =================================================================================================