The NISCA protocol is an implementation of the Port-to-Port Driver (PPD) protocol of the SCA that provides port-to-port communications in OpenVMS cluster systems based on interconnects such as Ethernet as well as in Cluster over IP.
The NISCA protocol consists of the following layers:
- Port-to-Port Driver (PPD)
- Port-to-Port Communication (PPC)
- Transport (TR)
- Channel Control (CC)
- Datagram Exchange (DX) or IP header Exchange