Dsl become unreachable at the fixed period of the time

Hi folks.
I have a TP-Link TD-W8970 v1.2(ADSL Modem/router) with OpenWrt 19.07.4 installed on it.
Everything looked good until yesterday. but today It keeps disconnecting from dsl network.

First I add this option: option pppd_options 'debug' and then chck for logs and I see this:

No response to 5 echo-requests
Serial link appears to be disconnected.
Connect time 0.5 minutes.

Since my dsl line quality is not perfect(I've talked about it here before), I apply this config to prevent from disconnecting:

uci set network.wan.keepalive='150 15'

After that, the dsl link doe's not disconnect by it self anymore, but I still have timed out. and the stranger point is it happens in a very fixed period of the time.
When I see my ping result(about 2000 icmp packet), I got 30 reply then 31 timed out and it goes on like a cycle and this fixed number never changes.

1 Like

It was ISP Fault and after a day, it seems they fixed the problem.