Description: The remote connection endpoint (identified by ptopoConnRemoteChassis and ptopoConnRemotePort of this row) may be connected to the local port (identified by ptopoConnLocalPort of this row) through either an unidirectional or bidirectional link. This object is used to indicate the directionality of the connection and in the case of unidirectional links this object indicates whether the remote connection endpoint is on the transmit or the receive link.

For example, in case of optical interfaces where the transmitted and received signals travel on 2 different strands of fiber, it is possible that each fiber terminates at a different device. For instance, the transmit and receive fibers of the local port may be connected to different optical amplifiers. This object could then be used to indicate whether the remote device is on the transmit or the receive fiber of the local port.

If the remote connection endpoint is connected to the transmit fiber of the local port then cPtopoConnExtLinkDirection is set to 'transmit'. If the remote connection endpoint is connected to the receive fiber of the local port then cPtopoConnExtLinkDirection is set to 'receive'. If both the transmit and receive fibers of the local port terminate at the same remote connection endpoint then this object is set to 'both'. Individual entries for 'transmit' and 'receive' should not be created in this case. Note that in the case of a port connected to a broadcast medium, there can be multiple entries associated with the port, with this object set to 'both'.