Mirror operating mode: High Performance (asynchronous), No witnessOnce I have configured mirroring it was working for several hours. It synch data and there was no unsent data.After checking mirror status in 8 hours I found that mirroring is in suspended mode.Mirror monitor shows â€œWaiting for dataâ€ and then Suspended in principle where Mirror shows only Suspended. I check logs and I found this message: 2011-05-02 15:19:30.28 spid25s Error: 1474, Severity: 16, State: 1.2011-05-02 15:19:30.28 spid25s Database mirroring connection error 4 'An error occurred while receiving data: '121(The semaphore timeout period has expired.)'.' for 'TCP://:'.2011-05-02 15:19:51.71 spid30s Error: 1474, Severity: 16, State: 1.2011-05-02 15:19:51.71 spid30s Database mirroring connection error 2 'Connection attempt failed with error: '10060(A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)'.' for 'TCP://:'.