AF_DECnet Address Families

The AF_DECnet Address families include:

DECnet Phase IV node addresses

DECnet Phase IV node addresses are hierarchical, indicating the a routing area and the node

number within that area. The binary format of the address is a 16-bit unsigned integer. The high-order 6 bits indicate the area, the low-order 10 bits are the node number within the area.

The ASCII format of the address is area.number with area in the range 1-63, and number in the range 1-1023.

For example: A DECnet node address in area 5, number 7 is represented as follows:

DECnet extended addressing

DECnet extended addressing allows the DECnet NSP transport to be run over the OSI routing layer. Sockets opened via AF_DECnet will assume that addresses of length 3-20 bytes are OSI-style addresses.

DECnet objects

DECnet client tasks specify the server task they want to communicate with by using network object number and task names. The DECnet object number is an 8-bit unsigned value. Object numbers in the range 1-127 are reserved as generic objects for Digital use. Numbers 1-128 are available for user-written generic objects.

If the object number is 0, then the network connect is done to a specific server task name. Task names are 1-16 byte ASCII strings.

For example: