1.1 Glossary

This document uses the following terms:

acknowledgment (ACK): A signal passed between communicating processes or computers to signify successful receipt of a transmission as part of a communications protocol.

client/server mode: A mode that consists of one server with many client connections (one-to-many). From the perspective of each client, there is only one connection: the connection to the server.

data frame (DFRAME): A DirectPlay 8 frame that exists in the standard connection sequence space and typically carries application payload data. The total size of the DFRAME header and payload should be less than the Maximum Transmission Unit (MTU) of the underlying protocols and network. For more information, see the DirectPlay 8 Protocol: Reliable Specification ([MC-DPL8R] section 2.2.2). See Also, command frame.

DirectPlay: A network communication library included with the Microsoft DirectX application programming interfaces. DirectPlay is a high-level software interface between applications and communication services that makes it easy to connect games over the Internet, a modem link, or a network.

DirectPlay 8: A programming library that implements the IDirectPlay8 programming interface. DirectPlay 8 provides peer-to-peer session-layer services to applications, including session lifetime management, data management, and media abstraction. DirectPlay 8 first shipped with the DirectX 8 software development toolkit. Later versions continued to ship up to, and including, DirectX 9. DirectPlay 8 was subsequently deprecated. The DirectPlay 8 DLL continues to ship in current versions of Windows operating systems, but the development library is no longer shipping in Microsoft development tools and Software Development Kits (SDKs).

DirectX: Microsoft DirectX is a collection of application programming interfaces for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms.

DirectX Diagnostic (DXDiag): DXDiag.exe is an application that uses the DirectPlay DXDiag Usage Protocol [MS-DPDX] traffic.

DPNID: A 32-bit identification value assigned to a DirectPlay player as part of its participation in a DirectPlay game session.

game session: The metadata associated with the collection of computers participating in a single instance of a computer game.

globally unique identifier (GUID): A term used interchangeably with universally unique identifier (UUID) in Microsoft protocol technical documents (TDs). Interchanging the usage of these terms does not imply or require a specific algorithm or mechanism to generate the value. Specifically, the use of this term does not imply or require that the algorithms described in [RFC4122] or [C706] must be used for generating the GUID. See also universally unique identifier (UUID).

group: A collection of players within a game session. Typically, players are placed in a group when they serve a common purpose.

host: In DirectPlay, the computer responsible for responding to DirectPlay game session enumeration requests and maintaining the master copy of all the player and group lists for the game. One computer is designated as the host of the DirectPlay game session. All other participants in the DirectPlay game session are called peers. However, in peer-to-peer mode the name table entry representing the host of the session is also marked as a peer.

host migration: The protocol-specific procedure that occurs when the DirectPlay peer that is designated as the host or voice server leaves the DirectPlay game or voice session and another peer assumes that role.

HRESULT: An integer value that indicates the result or status of an operation. A particular HRESULT can have different meanings depending on the protocol using it. See [MS-ERREF] section 2.1 and specific protocol documents for further details.

Internet Protocol version 4 (IPv4): An Internet protocol that has 32-bit source and destination addresses. IPv4 is the predecessor of IPv6.

Internet Protocol version 6 (IPv6): A revised version of the Internet Protocol (IP) designed to address growth on the Internet. Improvements include a 128-bit IP address size, expanded routing capabilities, and support for authentication and privacy.

Internetwork Packet Exchange (IPX): A protocol that provides connectionless datagram delivery of messages. See [IPX].

little-endian: Multiple-byte values that are byte-ordered with the least significant byte stored in the memory location with the lowest address.

modem link (or modem transport): Running the DXDiag application over a modem-to-modem link. See Also, serial link.

name table: The list of systems participating in a DXDiag, DirectPlay 4, or DirectPlay 8 session, as well as any application-created groups.

name table entry: The DN_NAMETABLE_MEMBERSHIP_INFO structure ([MS-DPDX] section 2.2.33) along with associated strings and data buffers for an individual participant in the DXDiag session. These could be considered players.

network byte order: The order in which the bytes of a multiple-byte number are transmitted on a network, most significant byte first (in big-endian storage). This may or may not match the order in which numbers are normally stored in memory for a particular processor.

payload: The data that is transported to and from the application that is using either the DirectPlay 4 protocol or DirectPlay 8 protocol.

peer: In DirectPlay, a player within a DirectPlay game session that has an established connection with every other peer in the game session, and which is not performing game session management duties. The participant that is managing the game session is called the host.

peer-to-peer: A server-less networking technology that allows several participating network devices to share resources and communicate directly with each other.

peer-to-peer mode: A game-playing mode that consists of multiple peers. Each peer has a connection to all other peers in the DirectPlay game session. If there are N peers in the game session, each peer has N–1 connections.

player: A person who is playing a computer game. There can be multiple players on a computer participating in any given game session. See also name table.

serial link (or serial transport): Running the DXDiag application over a null modem cable connecting two computers. See also modem link.

service provider: A module that abstracts details of underlying transports for generic DirectPlay message transmission. Each DirectPlay message is transmitted by a DirectPlay service provider. The service providers that shipped with DirectPlay 4 are modem, serial, IPX, and TCP/IP.

User Datagram Protocol (UDP): The connectionless protocol within TCP/IP that corresponds to the transport layer in the ISO/OSI reference model.

wide characters: Characters represented by a 2-byte value that are encoded using Unicode UTF-16. Unless otherwise stated, no range restrictions apply.

MAY, SHOULD, MUST, SHOULD NOT, MUST NOT: These terms (in all caps) are used as defined in [RFC2119]. All statements of optional behavior use either MAY, SHOULD, or SHOULD NOT.