EXFO FTB-8500 Series for FTB-500 - Manual (Page 170)

Port Tabs
156 FTB-8500 Series and FTB-8120NGE/8130NGE
Advanced Auto-Neg. TX
Negotiate Button
The Negotiate button allows starting the auto-negotiation process. The
auto-negotiation process last until the auto-negotiation has succeeded
(completed) or the auto-negotiation is manually disabled.
When Automatic is selected as speed, the auto-negotiation uses the
following prioritization scheme to ensure that the highest common
denominator ability is chosen (electrical interfaces)
.
1 1000Base-T full duplex
2 1000Base-T half duplex
3 100Base-TX full duplex
4 100Base-TX half duplex
5 10Base-T full duplex
6 10Base-T half duplex