Legacy Document

Important: The information in this document is obsolete and should not be used for new development.

Inside Macintosh: Networking With Open Transport / Part 2 - Open Transport Reference

Chapter 30 - AppleTalk Reference / AppleTalk Addressing Reference

The DDP Address Structure
You use the DDP address format, specified by the DDP address structure, to identify the socket address for your endpoint. The DDP address structure is defined by the DDPAddress data type.
struct DDPAddress
{
   OTAddressType  fAddressType;
   UInt16         fNetwork;
   UInt8          fNodeID;
   UInt8          fSocket;
   UInt8          fDDPType;
   UInt8          fPad;
};
typedef struct DDPAddress DDPAddress;
FIELD DESCRIPTIONS

fAddressType
A number that specifies the format of the address. For a DDP address this is always the constant AF_ATALK_DDP.
fNetwork
A 16-bit number in the range 0 to 65,534 that specifies the network number. The network number 65,535 (all bits set to 1) is reserved by Apple Computer, Inc. The network number 0 specifies the node's local network.
fNodeID
An 8-bit number in the range from 0 to 255 that specifies the node ID. A node ID of 255 is the broadcast address; a node ID of 0 specifies your own local node and is illegal other than
at bind time. For other values, refer to Inside AppleTalk,
second edition.
fSocket
An 8-bit number in the range of 1 through 254 that specifies a logical entity on your node. A socket number of 0 at bind time instructs Open Transport to dynamically assign a socket number. For other values, refer to Inside AppleTalk, second edition.
fDDPType
A number identifying the DDP type field. Unless you are using the DDP protocol directly, set this field to 0. For additional information see the chapter "Datagram Delivery Protocol (DDP)"and Inside AppleTalk, second edition.
fPad
Reserved. Set to 0.