Syslog server shows this when it reboots:
<3> SYSTEM REBOOTED (Reason: 91, lifecycle: 2508)
What is Reason: 91 ?
<7> ++++ send error or timeout: code=901, mtd=11
192.168.1.108 24/03 12:42:32.933
<7> ++++ mwi subs failed
192.168.1.108 24/03 12:42:32.935
<7> SipDlg:MMI:?Hdr=47
192.168.1.108 24/03 12:42:42.937
<7> sendto err(401) 0:5060, rc=-260, s=7
192.168.1.108 24/03 12:42:42.939
<6> ==== Networking is ready ====
192.168.1.108 24/03 12:43:13.770
<0> IP Address= 192.168.1.108 192.168.1.108 24/03 12:43:13.772
<0> Gateway = 192.168.1.1 192.168.1.108 24/03 12:43:13.774
<0> Netmask = 255.255.255.0 192.168.1.108 24/03 12:43:13.776
<3> SYSTEM REBOOTED (Reason: 91, lifecycle: 2508)
192.168.1.108 24/03 12:43:13.778
<0> SLIC_init ... 192.168.1.108 24/03 12:43:13.831
<0> Reset SLIC... 192.168.1.108 24/03 12:43:13.833
<0> SLIC & DAA is initialized 192.168.1.108 24/03 12:43:15.491
<6> Start Main Service Now 192.168.1.108 24/03 12:43:17.554
<7> Voice Main
192.168.1.108 24/03 12:43:17.557
<7> [CPT] --- FXS s/w tone generator (0) ---
192.168.1.108 24/03 12:43:17.561