
The DB9 connector is the boundary of the physical layer (PHY) of the token
ring adapter. This connector is not part of the ISO standard, which defines
the interface at the Medium Inteface Connector (MIC) rather than at the PHY.
A PHY/MIC cable (not supplied) must be used to connect the PHY and the MIC.
This cable is readily available because this is the method used by IBM
token ring adapters to connect to the MIC.

The +5V and GROUND signals may be used to supply power to a media adapter (not
supplied) that plugs directly into the DB9 connector. These signals are not
used by the MIC and are not part of the ISO standard. They are
provided for IBM
compatablility.

The DB9 connector is metal. The outside of the connector is a SHIELD.
It connects to the outside SHIELD of the PHY/MIC cable.

