DirectPlay 6.1a Launches Stable Multiplayer Game Connections (236610)

SYMPTOMS

Before the release of DirectPlay 6.1a on Windows NT 4.0 Service Pack 6, DirectPlay on Windows NT 4.0 had too many race conditions (one process assuming the other process has stopped responding or is still responding when the opposite is true), blocked joins, and unexpected disconnects to be considered a reliable protocol for networked games.

The following are difficulties experienced with networked (multiplayer) games on DirectPlay with Windows NT 4.0 before the release of DirectPlay 6.1a:

A player cannot join a game that is in session.
A player's connection to the game quits unexpectedly.
A player with a serial or modem connection cannot maintain a session for an extended period of time.
A player's gaming screen freezes during a joint session scenario.
Certain players in the game cannot move while others are moving.
The players cannot tell when another player has left the game.
When multiple players leave a game, DirectPlay shuts down itself and the game.
When the designated host tries to quit a peer-to-peer session, the game crashes and the host's migration does not work.
During a guaranteed send (typically because a player unexpectedly quits the game), a large timeout delay occurs.

RESOLUTION

DirectPlay 6.1a is available in Windows NT 4.0 Service Pack 6 and later. To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

http://www.microsoft.com/windows/servicepacks/ -or-
152734 how to obtain the latest windows nt 4.0 service pack

For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/directory/overview.asp

MORE INFORMATION

Typically, the design of networked (multiplayer) games accommodates Windows NT 4.0 as well as Windows 9x platforms. It is not uncommon for Windows NT to serve as a host or server in client-server games or as a lobby platform. Many games were developed to work on Windows NT; thus these games can also participate in peer-to-peer sessions with a peer-designated host. Windows NT 4.0 is a reasonably common development platform for multiplayer features in games.

DirectPlay is the part of DirectX that interfaces between programs and communication services (Internet, modem link, network) to allow game players to find game sessions and sites and manage the flow of information between hosts and players, regardless of the underlying online service or protocol. Microsoft DirectX is a group of technologies designed to enhance running programs with numerous multimedia elements (graphics, video, 3-D animation, surround sound); it is built directly into Microsoft's operating systems. For example, Windows NT 4.0 contains the DirectX 2.0 release of Microsoft DirectDraw, Microsoft DirectSound, and Microsoft DirectPlay, and it supports DirectX 3.0 functionality with the addition of Windows NT 4.0 Service Pack 4.

The successful implementation of DirectPlay 6.1a has involved changes to the following files for Windows NT 4.0 SP6:

dPlay
dplaypr
paketize
api
apphack
dxdiag
comport
dpmodemx
pdb
sym

Even though DirectPlay 6.1a is released in Windows NT 4.0 Service Pack 6, the DirectPlay 6.1a files can be installed on any computer running Windows NT 4.0 Service Pack 3 or later.

REFERENCES

For more information on DirectX and DirectPlay 6.1a, please visit the following Microsoft Web site:

http://msdn.microsoft.com/directx/downloads.asp

For additional information about modification to DirectPlay 6.1a's interprocess communication facilities (IPCs), click the article number below to view the article in the Microsoft Knowledge Base: