4 - SPX - Sequenced Packet Protocol

SPX PCI

Connection Control (1 byte)

Datastream Type (1 byte)

Source Connection ID (2 bytes)

Destination Connection ID (2 bytes)

Sequence Number (2 bytes)

Acknowledge Number (2 bytes)

Allocation Number (2 bytes)

Extended Acknowledgment (2 bytes)

SPX Data (1-534 bytes)