What layers do IPX and SPX protocols operate in the OSI model?

The IPX (Internetwork Packet Exchange) protocol operates at Layer 3 of the OSI model, which is the network layer. This layer is responsible for routing packets across different networks, making IPX suitable for facilitating communication between various nodes within a network.

SPX (Sequenced Packet Exchange), on the other hand, operates at Layer 4, the transport layer. This layer provides communication services directly to the application processes running on different hosts. SPX ensures that data packets are delivered in sequence and without errors, which is essential for maintaining the integrity and order of communication.

Therefore, the correct pairing of IPX and SPX protocols within the OSI model highlights the different roles they play in the networking process, with IPX managing network routing and SPX handling the delivery of data segments.