Technology Works Ethernet Cards (TechWorks NuBus cards) ship with Apple's EtherTalk software, both AppleTalk Phase 1 and Phase 2.
On a Phase 1 EtherTalk network, AppleTalk Remote Access allows you to place calls, but it WON'T allow you to answer calls.
You need to upgrade to Phase 2 EtherTalk to enable the Answer Calls or server option within AppleTalk Remote Access.