HT812 network problems, packet loss, WAN blinking 6times


Hi, I’m facing troubles with my HT812s.

The HT812 is connected via WAN Port to the Network. In my tcpdumps I can see packet loss of 30% during a call. The packet loss is not randomly, it comes in periods and resists for 2 or 3 seconds. In this 2-3 seconds, no voice communication is possible.

After investigating the problem, I recognized that the WAN-LED is not on, it is only blinking 6 times. In the manual i can’t find any description for a blinking WAN-LED. What does 6 times blinking mean?

Also, when I unplug the WAN Port, and then replug the WAN-Port. The blinking stops and the error disapears. But thats no solution, eg. after cycling the power, the problem comes again.

The WAN Port is used because of Auto-Provisioning via DHCP.


Edit: Problem found (see this post), Ticket created


My pure guess: IP CONFLICT.


Hi, IP CONFLICT was a good guess, but there are only 4 devices in the network.

Is it possible, that there are troubles with bridge-mode?

I activated syslog, here are some interesting messages

Syslog message: (unknown): HT812 [00:0B:82:B7:C2:F6] []NetworkMonitorHelper::sendSIGUSR1, send signal to restart /var/run/ …
Syslog message: (unknown): HT812 [00:0B:82:B7:C2:F6] []EventManager::run: Dispatching event 248 (NET_DUPLICATE_IP) on port -1:-1:
Syslog message: (unknown): HT812 [00:0B:82:B7:C2:F6] []EventManager::run: Dispatching event 247 (NET_PUBLIC_IP_CHANGE) on port -1:-1:
Syslog message: (unknown): HT812 [00:0B:82:B7:C2:F6] []EventDuplicateIP: false
Syslog message: (unknown): HT812 [00:0B:82:B7:C2:F6] []NetworkMonitorHelper::sendSIGUSR1, send signal to restart /var/run/ …


Set static IP if possible ?
log you show is ok i think as
EventDuplicateIP: false
Which mean no conflict ?

But for more i think you should open ticket with GS, dev could say more.


Ok, thanks. I will open a ticket and if I got any solution, I will post it here.

PS.: it definitly depends on this DuplicateIP Event, because it repeats every 10 seconds, like the voice


So, i found the factors which produce this behaviour. The problem is a setting in my DHCP Server, which never makes troubles for other VoIP Devices.

When the DHCP-Server sends in Option 3 a Router-IP which is not online in this moment, the HT-812 hangs in a “DHCP-Loop”. The HT-812 is configured, has an IP, making calls and visiting its configuration website is possible. But every 10 seconds the DHCP-Client restarts and request an IP from the DHCP-Server. The HT-812 doesn’t really checks, if the Router-IP is a real router, it only needs an IP which is online in this moment. Or the DHCP-Server sends no Option 3.

For me, thats not a normal behaviour, because my VoIP network is isolated from the rest. And only for update or service I activate my gateway. I opend a ticket and i hope Grandstream will fix this.



have you resolved this problem? We have same situation setting HT818 in bridge mode.


Hi, Grandstream confirmed my BugReport (Ticket) and forwarded it to devTeam. I hope there is a fixed version in the near future.