[App_rpt-users] CLI help

Can anyone tell me what this means in my CLI? [Jun 27 12:47:44] NOTICE[2177]: chan_sip.c:14418 handle_request_invite: Call from '' to extension '+901148422885410' rejected because extension not found. [Jun 27 12:48:04] WARNING[2177]: chan_sip.c:1964 retrans_pkt: Maximum retries exceeded on transmission 768cac067094ca767d045f9ac57d60d3 for seqno 1 (Critical Response) -- See doc/sip-retransmit.txt. N1XBM*CLI> So I do have to extensions setup one is my tablet (which is off) I also have my cell phone (which I have in airplane mode). Is someone trying to hack my server? Thank you