Hi everyone,
I'm dealing with a frustrating upload speed issue on my DEC840 that I can't seem to figure out.
Currently, my WAN is connected to my ISP's ONT using an FS SFP-10G-T (SFP+ to RJ45) transceiver in one of the DEC840's 10G ports. When I run a speed test, I get around 2 Gbps download, but my upload is capped at roughly 500 Mbps.
Suspecting the copper transceiver was the bottleneck, I moved the WAN connection to one of the DEC840's native 1 Gbps RJ45 ports. As expected, my download speed dropped to ~940 Mbps, but surprisingly, my upload actually increased to ~700 Mbps.
Thinking I was on the right track and just dealing with a issue on the transceiver, I bought an unmanaged switch with 2.5 Gbps RJ45 ports and 10 Gbps SFP+ ports bypass it.
- I connected the ONT to the switch's 2.5G port.
- I connected the DEC840 to the switch's 10G port via a 10Gtek SFP+ DAC cable, completely bypassing the FS copper adapter.
To my surprise, when I retried the speed test, I was right back to where I started: 2 Gbps down, and stuck at ~500 Mbps upload.
It seems like there is an underlying issue with how OPNsense/FreeBSD is handling outbound traffic on the SFP+ interface itself, regardless of whether I use a transceiver or a switch.
I should also mention that I'm dealing with the infamous PPPoE for this connection. While I am seeing packet loss during the speed tests, that still doesn't explain the 200 Mbps discrepancy. If PPPoE single-core performance was the only bottleneck, the 1G RJ45 port shouldn't be outperforming the 10G SFP+ port
Has anyone experienced this or have any ideas on what tunables/settings I should check next?
Thanks in advance!