This is the Hiway Director board of the Hiway Traffic Director.

This card contains circuitry required for polling and callup functions, as well as optical isolators, drivers, and circuitry for preferred access functions.

Issue number 8 of this card is required for LCN/Hiway Gateway compatibility. For heavily loaded Hiways connected to the LCN via Hiway Gateway, the round-robin version of this board, 51304283-100, is recommended.