The result signaling software will be a part of the ATM campus testbed. UNI 3.1 . Significant modification of UNI 3.0. Signaling protocol for narrow-band ISDN Q2931 . NRL developed a set of object oriented software structures suitable for application level protocol development which they called FrameWork.
Next figure shows the internal structure of the signaling software.
Upwards messages demultiplexed at the Lower Port Mux. Each port has a protocol stack to process the messages coming from that port. In the middle of the protocol stack is a Call State finite state machine. A PNNI setup message goes through the Port Protocol stack and reaches the control processor which all the routing and admission decisions are made. The detail of the software will appear in a technical report.