Unable to receive inbound callas

hi,

i am unable to receive inbound calls for my asterisk-now PBX

any information would be helpful

[2015-03-18 08:32:59] NOTICE[15917]: res_pjsip/pjsip_distributor.c:255 log_unidentified_request: Request from ‘“XXXXXX” sip:[email protected]’ failed for ‘192.168.81.252:5060’ (callid: [email protected]) - No matching endpoint found

I am able to make outbound calls