I have an office running a fibre-to-the-premises connection which utilises PPPoE to the ISP.

This is connected directly to WAN1 port on the ER605v1 and pings are allowed on this interface.

This works - the connection is generally reliable. I do however monitor all my sites via ICMP to keep an eye on things.

The one thing that's bugging me about this is over time, the connection gets an increasing amount jitter on it. This seems to be directly related to uptime of the router (not the PPP session). After a reboot of the router the jitter will be minimal - as good as any other site I have running (this is the only one on an ER605). But over the next day, it gradually builds until it's really a very noisy connectiion. See below.

 

This is where I rebooted the router via a scheduled task at 19:00. Jitter after the connection is established is essentially zero.

This is the next 24h slot, you can see the jitter gradually coming in after 09:00.

..and the third day, jitter is then essentially at this level indefinitely until the router is rebooted again, it doesn't get any worse.

I have tried a factory reset of the router, and this has persisted on every firmware version over the last 2 years. It's not affecting day-to-day usage of the connection, just a weird frustrating issue. I initially figured it was a memory leak or something tying up a lot of CPU time on the router, but the OC200 controller does not show excessive usage on the device - 38-41% memory usage and 0-8% cpu usage throughout. It is not a busy connection, the jitter is NOT being caused by usage. Dropping PPP does not 'reset the clock' - ONLY a reboot does.

I've been having this issue for a long time - and a ticket didn't get me anywhere (I was asked only basic troubleshooting then I simply stopped getting replies..) so just wondering if anyone is finding a similar thing happening for them.

Any suggestions on things to try to sort this out would be appreciated.