Resolve Unifi connectivity problems with 10G Tek SFP+ over RJ45 to 2.5GbE Ethernet
Resolve Unifi connectivity problems with 10G Tek SFP+ over RJ45 to 2.5GbE Ethernet
Hi, here’s what you might be experiencing: the connection speeds appear to differ depending on direction. This could be due to how the network interfaces handle traffic or limitations in the cable/adapter setup. Double-check the cable connections and ensure both ends support the required speeds.
I activated that feature and set jumbo frames in the global options.
SFP+ to rj45 adapters can be selective, particularly when switching between different data rates. It’s best to purchase the Ubiquiti Trasciever model with UACC-CM-RJ45-MG compatibility for multi-gigabit support. A standard generic transceiver might function but needs to handle 2.5GB speeds.
I don't rely on Jumbo Frames even at 10G speeds; they actually create more issues than benefits.
I managed to fix the problem by changing to a fibergaga transceiver, which resolved everything. I prefer matching unifi transceivers, but availability is limited. The drivers also caused issues with my 2.5Gbps Ethernet card.
It seems you've already discovered a workaround. These multi-speed transceivers can be quite finicky. I personally prefer the Mikrotik S+RJ10. I connect one to my Ubiquiti UXG-Pro to deliver 2.5Gbps Ethernet from a cable modem straight to the router. Other devices lack proper flow control or don’t have enough internal buffer space to manage sudden traffic spikes. This issue arises because your 10Gbps device attempts to transmit at 10Gbps signaling rates, which can overwhelm the slower link. To resolve this, it needs to temporarily store data so the slower connection can handle 2.5Gbps at full speed. If the buffer is too small, bursts of traffic may be dropped randomly. This is where iperf’s retransmissions come into play. Higher-end transceivers often manage flow control independently on each end. On UniFi switches, I also skip Flow Control, which can disrupt networks elsewhere—especially since they don’t let you disable it per port like premium switches do. Flow Control and pause frames are still basic.