end of row (data center) (EoR)
End of Row (EoR) is a networking concept used in data centers. Alternatively, there is Middle of Row( MoR) and Top of Rack( ToR).
In the EoR concept, all servers from the different server racks are connected to the end-of-row switch without the individual rack switches being networked beforehand, as is the case with the ToR concept. The EoR concept uses thicker cables that run to each individual server in the racks. The EoR switch is located at the end of a row of racks. Where each rack row usually has its own EoR switch. In contrast, with the ToR concept, each rack has its own ToR switch.
The EoR switches are flexibly configurable and can be extended by a plug-in card if required. The number of ports is lower in this concept than in the ToR concept.