It's like for a Wireless bridge.. you are using a specific technology (IP or proprietary bridge) and some devices which could be different from a manufacturer to an other
As EOC isn't standardised with the EEEC.. you will need a pair of specific devices, yes sure.
Like some Wireless bridges (never mix brand A with brand B) , but also lots of "less common technologies" like long span, VDSL twisted pair, POE repeaters and port duplicators (with POE 30W, 60W, 95W..)
Better avoid Coax technologies that are POE powered only if a POE device is connected... it requires an additionnal POE splitter...
Veracity /Axis OEM are very good for this up to 500m, simple to use and no need for POE end device. It wil cover most needs.
Iperf is used in IT since 30 years now.. and can not be contested. Analog times are over with I believe, I think it's working , and I want to use a single device to test everything.... Now you need a PC without firewall in admin mode, a good PC card, and lots of freewares, and utilities, and accessories to build a network, setup and test it.
And anyhow, most technology (EOC , PLC, VDSL2, POE Repeaters) are limited to 100 Mb/sec so the results should be symetric and should reach 94/95 Mbit/s on TCP. sometime more when using UDP.
Let's add that EOC is only one technology, using actually proprietary frequencies, ... but technicians need also to test Cat5/6A/7 TP, VDSL, VDSL2, Long Span or Wireless bridges, optical fiber?? They need also to test remaing bandwidth on the network ... with propre test.... Iperf / Jperf can be used the same way ... so it's a kind of universal test tools now embedded in some Onvif Handheld devices (no need for a second PC)