Introduction/Scope

This document details the resource footprint and expected impact on normal operations for the main product components on the Windows platform. Specifications in this document refer to both Domain Time II Client and Server components, except as noted otherwise. References to Windows NT assume version 4.0 or higher.

This document is intended to provide information for product research and planning purposes only, it is not a statement of warranty or guarantee. Please see the product license agreement for details.

Program Modules/DLLs

• Domain Time II Server consists entirely of the DOMTIMES.EXE program and DOMTIMES.CPL control panel applet
• Domain Time II Full Client consists entirely of the DOMTIMEC.EXE program and DOMTIMEC.CPL control panel applet
• Domain Time II Thin Client consists entirely of the DOMTIMEC.EXE program
• Domain Time II Ultra Thin Client consists entirely of the DOMTIMEC.EXE program
• Domain Time II Audit Server (optional component, sold separately) consists entirely of DTAUDIT.EXE and DTAUDIT.CPL control panel applet
• Server and Clients also use DTTRAY.EXE, the optional system tray applet
• No new DLLs are installed
• No existing DLLs are replaced
• Note that optional programs and support utilities (such as DOMTIME.INI, DTSET.EXE and DTCHECK.EXE, DTREADER.EXE, DTDRIFT.EXE, and DTSYNC.EXE) may also be installed into the system directory or Program Files\Domain Time II folder during program installation. These programs may be deleted after installation without affecting the operation of Domain Time II Server or Domain Time II Client. Please see Distribution Files for specific information.

Hardware Interaction

• No direct control of hardware; Domain Time II runs in user mode and makes calls into kernel mode for standard, documented API functions.
• Time is set using standard calls to the Win32 SetSystemTime function. (On Windows for Workgroups, the DOS and BIOS interrupts are used.)
• Clock slewing is accomplished via the Win32 SetSystemTimeAdjustment() function.

Memory Footprint

CPU Usage/Tasking

For an idea of what these numbers mean, an NT 4.0 idle spooler service with no printers defined and no documents spooled typically uses 5 threads and uses 2384k of memory. A fully decked-out Domain Time Server with 15 threads typically only uses 416k.

Service Dependencies and Security Contexts

• Server Dependencies
  TCP/IP
  LanmanServer, the "Server Service" (will function without this service, but will generate a warning, and domain hierarchy functions will be unavailable)
  LanmanWorkstation, the "Workstation Service"
  
• Client Dependencies
  TCP/IP
• Windows
  The Windows Time (W32Time) service, if present, is adjusted (set to NoSync or disabled) during installation of Domain Time II. Additionally, the Windows Time Agent Control Panel applet (w32tmdt.cpl) is installed.
• Security Context, Windows
  Runs as a system service under the LocalSystem security context.
• Security Context, Win95, Win98, WinME
  Runs as a Windows "Simple Service."

Windows Registry

• Server parameters are stored in
         HKEY_LOCAL_MACHINE\Software\Greyware\Domain Time Server
  
• Server service information is in
         HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Domain Time Server
  
• Client parameters (any flavor of client) are stored in
         HKEY_LOCAL_MACHINE\Software\Greyware\Domain Time Client
  
• Client service information (any flavor of client) is in
         HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Domain Time Client
  
• Additional components are in
         HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Domain Time II [Component Name]
  

Network Protocols

Network Traffic

The amount of time-sync traffic varies by protocol used, as shown in the table below. The Domain Time II protocol also provides for master-slave failover, statistics gathering, sync on demand, and other non-time traffic.

Time Protocol	Typical Request	Typical Response
Domain Time II Server	8 bytes	16 bytes
Domain Time II Client	8 bytes	16 bytes
Domain Time I	2-24 bytes	16 bytes
NTP	48 bytes	48 bytes
TIME/ITP	0-4 bytes	4 bytes
HTTP	10-16 bytes	200-400 bytes

Note that Domain Time II components typically use the Domain Time II protocol for control information as well as time information. Control information (querying time zone settings, obtaining statistics, and so forth) varies based on the request.

Service Interaction Table

¹ Note 1: Domain Time II Server can provide time synchronization and display via HTTP, using a built-in custom web server. Domain Time II over HTTP service is disabled by default, but may be enabled on a per-machine basis from the control panel applet. HTTP uses the well-known TCP/IP port 80, as do most other web servers, including Microsoft’s IIS. Only one process can listen on port 80 at a time, so a machine serving Domain Time II over HTTP cannot also be a regular web server, and vice versa. If port 80 is already owned by another process when Domain Time II Server starts, and if Domain Time II Server is set to serve time via HTTP, Domain Time II Server will note the conflict in the event log and continue without HTTP support. Alternately, if you configure Domain Time II Server to find a free port, it will do so.

² Note 2: Domain Time II Server relies on NetBIOS-name-to-IP resolution. When propagating a level 1 synchronization trigger, Domain Time II Server running on the PDC enumerates time servers on the network using Microsoft’s LANMan API. This yields a list of NetBIOS machine names. Domain Time II Server then attempts to lookup the IP address for each server. This lookup will succeed if Microsoft WINS is running and properly configured, or if manual host information is maintained either through DNS or host/lmhosts files. Domain Time II Server running on non-PDC machines needs to be able to map the PDC’s NetBIOS name to its IP address, again either through Microsoft WINS or a manual configuration.

³ Note 3: During installation onto Windows machines, Domain Time Server and Client check for, and disable if found, the Windows Time (W32Time) service. During removal, Domain Time II automatically re-enables Windows Time if it is present on the machine. Running both Domain Time II and Windows Time simultaneously on the same machine will produce unpredictable results unless Domain Time II is configured to let Windows Time manage the clock.

Conclusion