System simple_cs = { Component client = { Port send-request; Port err-trap; } Component server = { Port receive-request; Port alert; } Connector rpc = { Role caller; Role callee; } Connector err = { Role source; Role sink; } Attachment server.receive-request to rpc.callee; Attachment client-request to rpc.caller; Attachment client.err-trap to err.sink Attachment server.alert to err.source }