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 Documentation\Technical\Resources\Resource Impact Statement

    Introduction/Scope


    Domain Time II is a time synchronization service for use on Windows systems. Domain Time also supports clients for several flavors of Linux, FreeBSD, Solaris (SPARC and Intel).

    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


    Memory usage of Domain Time II Server varies somewhat with the number of time protocols selected; at any one time, memory usage is also dependent on the number of simultaneous time requests being serviced. The table below shows actual memory usage for Domain Time components after each component has been running in a production environment for 96 hours:

    Component Memory Usage
    Master Server 416k
    Slave Server 948k
    Full Client 766k
    Thin Client 476k
    Ultra Thin Client 332k
    Audit Server 3560k

    CPU Usage/Tasking


    Domain Time II is a multi-threaded 32-bit application. Most activity and thread use is triggered on-demand, so CPU usage is typically less than 0.01% (unmeasurable)

    Component Threads
    Server 5 to 20*
    Full Client 5 to 7
    Thin Client 5
    Ultra Thin Client 3 to 4
    Audit Server 7
    *Depends on the time protocols selected and registry customizations

      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


    Domain Time II uses the following Registry entries:
    • 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


    All communications of time requests/responses use standard networking protocols and APIs. The TCP/IP ports used are:

    Time Protocol Port
    Domain Time II 9909 UDP
    9909 TCP
    Domain Time I N/A
    MS LanMan N/A
    NTP 123 UDP
    TIME/ITP 37 TCP
    37 UDP
    HTTP 80 TCP

    Network Traffic


    Network synchronization traffic is minimal. Domain Time II clients and servers generate network traffic only when making or servicing requests (no polling). Sync requests and time cascade pushes are made on both a synchronous and asynchronous on-demand basis. Timings for synchronous activities are user-adjustable.

      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


    The table below lists common Windows services and summarizes Domain Time’s interaction with them and its impact on their operation. The table reflects interactions with both Alpha and Intel versions of NT. The items listed in the Product category refer to all versions of the product, except where noted.

    Product Interaction with
    Domain Time II
    Impact on Operation
    Microsoft Active Directory Replication
    None None
    Microsoft Kerberos Authentication
    None Users will always be able to log into the network.
    Microsoft Domain Controller SAM
    None None
    Microsoft Domain Controller Replication
    None None
    Microsoft Internet Information Server (IIS)
    See Note 1 See Note 1
    Microsoft Exchange None Email and shared folder timestamps will be correct.
    Microsoft SQL Server None Field and record timestamps will be correct.
    Microsoft DNS None Zone replication will take place at the correct dates and times.
    Microsoft DHCP None Lease expirations will occur on the correct dates and times.
    Microsoft WINS See Note 2 Tombstoning and expirations will occur on the correct dates and times.
    Microsoft SMS None Package delivery and file timestamp comparisons will have the correct time on both the workstation and server.
    Microsoft Windows Time (W32Time)
    See Note 3 See Note 3
    Lotus Notes None Email and shared folder timestamps will be correct.
    Oracle DBMS None Field and record timestamps will be correct.
    Table 3. Interaction and Impact on Windows Services.

      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


    Domain Time II Server is an extremely well-behaved service, with minimal impact on Windows server operation. Domain Time II Client is a similarly dwell-behaved application on all Windows versions.

Domain Time II Software distributed by Microsemi, Inc.
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