E&M ports are not used to connect end user devices, instead FXO ports are. E&M ports are the most common form of analog trunk circuits, which uses special signaling paths that are separate from the trunk's audio path to convey information about the calls. E&M connections from routers to telephone switches or to PBXs are preferable to FXS/FXO connections because E&M provides better answer and disconnect supervision.
Dig Deeper on Network Administration
Related Q&A from Sudhanshu Gupta
One difference between managed and unmanaged switches is complexity. A managed switch is more complex and requires more skills, but it offers better ... Continue Reading
Unmanaged Linksys switches don't know where to send BootP and DHCP requests. Find out what to do to fix the problem of unmanaged switches and DHCP ... Continue Reading