Primary nodes poll secondary nodes in a predetermined order.
Secondaries then transmit if they have outgoing data. When configured as primary and secondary nodes, routers are established as SDLC stations. The SDLC commands described in this chapter pertain to routers configured as SDLC stations. This is in contrast to a router configured for SDLC Transport where the router is not configured as an SDLC station, but acts as an intermediary, passing SDLC frames between two SDLC stations across a mixed-media, multiprotocol environment. Use the commands in this chapter to adjust the router's LLC2 and SDLC parameters.