Establish-Connection-To-Network message X'08' and Disconnect-Connection-To-Network message X'09'

[duffy-ocraven]

Establish-Connection-To-Network message is indicated by a network_layer_message_type of X'08' followed by a 2-octet network number, then a 1-octet "Termination Time Value" in seconds, that the connection shall remain established in the absence of NPDUs being sent on this connection. A 1-octet value of 0 is permitted, which indicates that the connection should be considered to be relatively-permanent.

Disconnect-Connection-To-Network message is indicated by a network_layer_message_type of X'09' followed by a 2-octet network number.