Sequence of activation for SDLC PU2.0 fixed format
primary devices. LocalDeviceFirst specifies that DLS
establishes a connection with the SDLC End Station first.
Once the Local Device successfully responds, DLS then starts
up the SSP connection to the peer.
PeerFirst specifies that DLS starts the SSP connection
first, and contacts the SDLC End Station only
after receiving a CONTACT message from the peer.