The peers and Trunk SIP change the status unreachable and reachable again frequently.
I believe that i have a network trouble.
The network topology has 3 HP Switch connected directly to a Draytek, and the Asterisk and phones are connected to the Switches
Asterisk log show for each SIP peer:
[May 23 16:55:46] WARNING chan_sip.c: sip_xmit of 0x7fd01c0129c0 (len 608) to 10.6.1.79:5062 returned -2: Network is unreachable
[May 23 16:55:46] ERROR chan_sip.c: Serious Network Trouble; __sip_xmit returns error for pkt data
[May 23 16:55:46] WARNING acl.c: Cannot connect
CentOS Linux release 7.3.1611 (Core)
I appreciate your help.