SPP vs. IPC

SPP vs. IPC

Packet header format is of same length.

Last field usage differs:

- IPC uses for length or error indication.

- SPP uses for flow control.

Virtual connection implementation.

- IPC uses single public connection between two IPC entities, processes are unaware of connection.

- SPP uses private connection between two ports, process may use one more connections with a given port.

Flow control.

- IPC does not support flow control of data packets.

- IPC assumes upper layers provide flow control if needed.

- SPP provides flow control, modified dynamically.

Virtual connection termination.

- For IPC, terminates if nodes cannot communicate or if it is idle for some period of time.

- For SPP, terminates if process closes connection, or if nodes cannot communicate.

Acknowledgments.

- IPC does not transmit acknowledgments on an idle connection.

- SPP periodically transmits acknowledgments on an idle connection.