I have a issue i can't wrap my head around, i managed a fortivoice 100e sometimes user experience drop calls when connected will a caller for a few seconds or minutes, so far i upgraded the firmware to v6.0.9, change the sip ports and port forwarding on both the box and firewall. the phone share a connection with a desktop and it connected on a fortiswitch that has QOS enable for the phone. any idea about this issue.
I have the same issue on a FVE-100E I have updated to the latest firmware 6.4.3, My client is using analog lines where I use a Grandstream 4108 as the gateway. Inbound calls work fine, outbound calls drop after one ring. Checked the logs they say call dropped by callee. Started happening when I updated the firmware to use two new FON-380 phones.