The linkage between the socket data structures and the protocol-specific data structures is identical to that found in the Internet communication domain. All NS protocol input is received by the NS interrupt routine, nsintr , which is invoked at software-interrupt level when a network interface receives a message to be processed by an NS protocol module. The interrupt routine performs consistency checks on the packet, and then determines whether to receive, forward, or discard the packet. If the packet is to be received, the nsintr routine locates the NS protocol control block for the receiving socket according to the sender's address and the destination port number. The routine then passes the packet to the receiving protocol.
Returns protocol headers on each message with data.
System Configuration Two separate network interfaces for the XNS protocol can be implemented, the IEEE 802.3 Ethernet interface and the Standard Ethernet interface, which both run on 10Mbps Ethernet hardware. The host ID in the XNS address uses the Ethernet address. Multiple Ethernet hardware interfaces are supported in the same system. However, to simplify the design, one host ID for each Ethernet interface is used. Even though multiple host IDs are used in the same system, packets destined for a specific host ID are received and processed accordingly.