Good day.

I'm having issues with my ER605 and CityFibre 900Mbps symetrical connection. Speeds are lower compared to the ISP supplied router and speed tests fails pretty much every time.

Previously, I had 4G broadband provided by Three network and used a NR5103E in passthrough mode to the WAN. Had no issues with it, 2-300Mbps download throughput and speedtests ran flawlessly every time.

Recently had CityFibre 900Mbps symetrical installed and am experiencing issues with the connection. Speed tests fail constantly and the speeds are slow. 

CityFibre have been out and inspected the fibre and there is very little loss/attenuation - it's pretty much perfect. 

If I plug in the ISP supplied router, it's quick with no drop outs. Speed tests run more or less every time with over 900Mbps every test.

I'm 99.9% certain its the ER605. all local computers and laptops are hardwired through a switch with a single cable going from the switch to the ER605. 

Plugging directly into the ER605, I get the described issues. If I unplug from the ER605 and straight into my laptop the issues go away.

If I unplug the rest of the network from the ER605, the issues remain.

I've turned off deep packet inspection, there's no QoS, policy routing, bandwidth limiting - it's pretty much stock settings really. 

The only thing I can think of is that the ER605 can't handle the connection and I'm in need of an upgrade. I've searched the forums for similar issues and whilst not exactly the same, there seems to be a concensus that the ER605 can't handle gigabit wan connections?