I will like to explain the meaning of the term virtual private network server and will not like to go into the technical definition of this term. The server is a well known term. There are clients on the one hand and some info source on the other hand and the server is in between to connect them. If the server is of file server type, then the file server will store all the files. The source here is a file. The clients will want a file and will request the file server to give an access to view a particular file. The server will give access to that file after getting the clients credentials verified.

The virtual private network is an interesting term when two or more devices
Have a secured and private communicating tunnel; it is called as the virtual private network. The important fact here is that this tunnel is across the public network like the internet. These virtual private network devices can be of two types. In the first case it is the computer running VPN software. In the second case it will be a VPN enabled router. It can allow you your home computer to get connected to your office computer. As a mater of fact any two computers at any two locations can get connected over internet using this virtual private network server.

The point to be noted is that the data is traveling through the public network like the internet. And still the data remain perfectly secured and private. This is the reason of calling it as the virtual private network server. This is possible because there is strong encryption of data. If someone tries to listen to this data, he will not understand anything as the data is highly strong encrypted. The data travels as packets. Is it possible to alter these packets on the way when they are traveling on public network like internet? No. This is not possible as these virtual private networks have very good and highly sophisticated ways for monitoring these packets. The encryption and verification is done in the best possible method.

Thus virtual private network server is a piece of software or the hardware that can act a gateway into the whole network or in the single computer. This virtual private network server is always in “always on” position. It is all the time listening to the clients. When the clients request for the connection, it immediately connects after verifying client credentials. A virtual private networking server can be a piece of hardware also. This virtual private networking server has brought a new revolution on the communications.

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What are the uses of home network dvd server? Let us understand the role of the server first. In the dvd server the server stores all the dvds. The home network will consist of different PCs in different rooms. The clients in this net work will be family members in different rooms. The family members want to access certain dvd. The home network server will provide them with quick access to that movie after getting their credentials verified.

The first benefit of this home network server is that all your dvds are stores in one secure place. They are well protected. When you want to access any movie, there can be lot many choices for selection. You can select the list of movies of your favorite actor. You can get list of movies as per the name of one particular director. There can be different criterions of selection.

You can not have this facility with your ordinary dvd changer. The very process of selecting the movie can have a wide choice in home network dvd server.

The second benefit is restricted access to kids. There are adult movies. You do not want your kids to see those adult movies. When you have a simple collection of dvds and a dvd changer, it is not possible to restrict the access to the adult movies to your kids. You can see one movie simultaneously in all the rooms. You can see different movies in different rooms at the same time.

There are many other benefits of this home network server system. You can have your video bookmarks. This means you can have your own songs sequences or scene sequences and their collections. You can work out lot many permutation and combinations with this type of home network dvd server.

This home network dvd server needs a different type of technology. This is the reason that there is not much commoditization of this product. As a result there are not many products in the market in this category. There are not many branded low priced products available in this category. The idea seems simple. But it is difficult to execute. There are different patent laws which make it all difficult. The present reality is that there is one high end product in home network server category. This is kaleidescape system.

The cost of this product is prohibitively high. It is possible to build your own home network dvd server. There are many guides available on internet. You can use them and build your own home network dvd server to suit your present and future needs. The commercially available home network dvd server system provides lot many additional features and it is advisable to visit their web site to get additional info.

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HP (Hewlett Packard) has a long history with Laser Printers, and Laser Printer technology. Going back to the first commercial laser printer released way back in 1984, HP has generally lead the way in commercial quality Laser Printers and their associated technology.

With the first network printer being released in 1991 being the Laserjet IIIsi, HP took over offices worldwide. The Jetdirect network card gave companies the freedom to put a printer on a separate location and link it to a lot of computers via the office network, instead of having the printer attached to and using the resources of a computer.

The Jetdirect interface has undergone many revisions in it’s long life, starting with the original XIO cards that contained one protocol such as TCP/IP or ipx/spx up to the current production set of the EIO product line that contains 5 protocol stacks and also auto-switchable 10/100/1000 network speeds.

As of May 1, 2007 HP is rolling out three new products that will again sweep the world with innovation.

Jetdirect 630n EIO Print Server MSRP $389.99

• IPv4 (standard TCP/IP) compliancy
• IPv6 compliancy - The new networking protocol coming into force in the US Federal government. This network system allows for vastly more IP addresses and an enhanced communication and security network
• Fully Compliant with Windows Vista, Mac OS X, Linux, and most flavours of Unix, Novell 5.1 or higher, Solaris 2.5, IBM AiX, Citrix Metaframe, and Windows Terminal Services
• Easy to use web-based configuration interface
• Security enabled using SNMP v1, v2, and v3 protocols
• Connectivity to 10base-T, 100 base-T, and 1000 Base-T Gigabit networks

Jetdirect en1700 External USB Print Server MSRP $149.99

• IPv4 (standard TCP/IP) compliancy
• IPv6 compliancy - The new networking protocol coming into force in the US Federal government. This network system allows for vastly more IP addresses and an enhanced communication and security network
• USB 2.0 and USB 1.1 backwards connectivity - allows for connection to most HP and some 3rd party printers and All-In-Ones by USB connection
• Fully Compliant with windows Vista, Mac OS x, Linux, and most flavours of Unix
• Easy to use web-based configuration interface
• Security enabled using SNMP v1, v2, and v3 protocols
• Connectivity to 10base-T or 100base-T networks

Web Jetadmin version 10

• Printer administration utility
• Runs using .net 2.0 framework
• Workstations can connect remotely to Web Jetadmin to allow users to communicate and monitor/control printers remotely through the central interface
• SQL database using Microsoft SQL 2005 Express database connection
• User role policies much like Windows Server 2003 to enable limited user control over functions of printers
• Ability to predict supplies needs and generate order requests for HP printer supplies before they run out
• Can run reports on printers such as page count, user page count, color pages vs black and white pages, and many more.

Of these products, the Web Jetadmin software is perhaps the most dynamic. Before this release, the package at current revision 8.1, was web browser based. Using the Sun Java Runtime Environment, and was very slow to perform any actions needed.

The new package was built from the ground up using the .net 2.0 framework and Microsoft’s ClickOnce application development path. It installs smoothly, and the Beta 2 release we tested was very clean to run and to use. Everything has been rebuilt from the ground up to allow for ease of use and fast response. Right-clicking the mouse now gives access to many layers of menus that control all aspects of the software.

The program can be almost entirely customized to give just the reports and information needed. Be it page counts right down to predictive reports such as when the print engine will need a maintenance overhaul. Using XML datafiles, the Web Jetadmin application is fully customizable and user controllable.

The database is proprietary and at this release is not available for opening up in an external application, only Web Jetadmin can access the database itself.

Compared to the older releases of Web Jetadmin - this version is very slick. If it fails, you just restart it, and it loads up remembering precisely where the settings were so you had your workspace available just as you left it.

We very much like this version - it is very clean and will be a vast improvement over the 8.1 version that is still tied to both Java and the web browser.

(edited 1/5/07 for removal of unsourced information)

Tim Morrison is a founding member of Morristreet.com, a technology company developed to bridge the gap between virtual and real worlds in the realm of 3d. Our goal is to be able to produce a 3d image on the computer and then produce it as a physical object - no matter what the complexity or detail involved. In this vein, we keep track of anything in relation to 3D imagery that can bring our goals closer, be it gaming consoles that can do more than play games, hardware imaging solutions, or software that can make our lives easier. Real World 3D is coming, Morristreet is in the lead!

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Network Time Protocol, or NTP as it is most commonly known, provides a mechanism to synchronise the time of computer devices and other network infrastructure. The protocol was originally developed for the Linux operating system by Dr D Mills of the University of Delaware. For more than two decades, NTP has provided time synchronisation of critical devices on the Internet making it one of the oldest protocols still in continuous operation. This article provides a brief overview of NTP and some of the technical phrases used in computer timing.

NTP was originally developed to solve the requirement of synchronisation of critical time processes across the Internet. The Network Time Protocols primary platform is the LINUX operating system. NTP is provided under the GNU public licence; however, it has also been sucessfully ported to the Windows operating system. LINUX is still however the primary platform associated with the Network Time Protocol.

NTP utilises the UDP (User Data-gram Protocol) over TCP/IP. NTP messages are communicated using UDP port 23, which is reserved solely for the use of NTP traffic. The protocol basically consists of a number of fields, which specify: time-offset, network delay and jitter relative to an accurate time reference. The information stored in each NTP packet allow a network time client to accurately synchronise time with a NTP server.

NTP is a structured protocol that operates in a hierarchical manner. At the top of the tree, a primary time reference is known as a stratum 1 time server. Servers that synchronise to a stratum 1 server are known as stratum 2 servers and so on down each level of the hierarchy. As the stratum increases, so generally precision decreases.

Over a number of years NTP has been enhanced to operate with a plethora of precision hardware clock devices, or reference clocks. NTP reference clocks are available for GPS hardware and also many of the National Radio Time and Frequency standards such as MSF, DCF-77 and WWVB. A number of third-party timing hardware manufacturers have installed precision crystals into their reference clocks to provide an accurate backup timing reference,.

A spin-off of the NTP protocol is SNTP or Simple Network Time Protocol, which is basically as the name implies, a simplified version of NTP. SNTP is generally used in small low-powered computing devices such as micro-controllers. It allows low-powered devices the ability to synchronise time to NTP servers over a network.

To summarise, NTP is a long-standing and widely used protocol for synchronising time between time critical processes. NTP has a linear heirarchical structure that can provide a timing resource for large numbers of clients. For applications that require critical timing, NTP provides a de-facto standard solution.

Dave W Evans provides technical authoring services to the time and frequency industries. Dave has published a number of articles and white-papers detailing the operation of NTP. Click here, if you would like more information on NTP server solutions.

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Computer time synchronization is highly important in modern computer networks, precision and time synchronization is critical in many applications, particularly time sensitive transactions. Just imagine buying an airline seat only to be told at the airport that the ticket was sold twice because it was purchased afterwards on a computer that had a slower clock!

Modern computers do have internal clocks called Real Time Clock chips (RTC) that provide time and date information. These chips are battery backed so that even during power outages, they can maintain time but personal computers are not designed to be perfect clocks. Their design has been optimized for mass production and low-cost rather than maintaining accurate time.

For many applications, this is can be quite adequate, although, quite often machines need time to be synchronised with other PC’s on a network and when computers are out of sync with each other problems can arise such as sharing network files or in some environments even fraud!

Microsoft Windows 2000 has a time synchronisation utility built into the operating system called Windows Time (w32time.exe) which can be configured to operate as a network time server. Microsoft and others strongly recommend that you configure a time server with a hardware source rather than from the internet where there is no authentication.

If you want to configure Windows Time service to use the internal hardware clock, then first check that w32time is located in the system services list in the registry, to check:

Click Start, Run then type regedit then click ok.

Locate and then click the following registry entry:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Time

It is highly recommended that you back up the registry as serious problems may occur if you modify the registry incorrectly, modifications to the registry are done at your own risk.

To begin configuration for an internal clock, click on the following subkey:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParameters

In the right pane, right-click ReliableTimeSource, then click modify.

In Edit DWORD Value, type 1 in the Value Data box, then click OK

Exit Registry Editor

To restart the Windows Time Service click Start, Run (or alternatively use the Command Prompt facility).

Type: net stop w32time && net start w32time

Then press enter.

To reset the local computers’ time, type the following on all computers except for the time server which must not be synchronised with itself:

w32tm -s

To configure the Windows Time service to use an external time source, click Start, Run and type regedit then click OK.

Locate the following subkey:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParameters

In the right pane, right-click Type then click Modify, in edit Value type NTP in the Value data box then click OK.

Now in the right pane, right click ReliableTimeSource, then click Modify.

In the Edit DWORD Value box, under Value Data, type 0, then click OK.

Right-click NtpServer in the right pane then click Modify.

In Edit Value, type the Domain Name System (DNS), each DNS must be unique.

Now click Ok.

For Windows 2000 Service Pack 4 only, set the time correction settings to do this locate:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParameters

In the right pane, right-click MaxAllowedClockErrInSecs, then Modify in the Edit DWORD Value box, , type a time in seconds max number of seconds difference between the local clock and the time received from the NTP server in order to be considered a valid new time.

Click OK.

To set the poll intervals locate:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParameters

In the right pane, right-click Period, then click Modify.

In the Edit DWORD Value box, under Value Data, type 24 then OK

Exit Registry Editor

Click Start, then Run then type the following and press Enter:

Net stop w32time && net start w32time

To reset the local computers’ time, type the following on all computers except for the time server which must not be synchronised with itself:

Network Time Protocol (NTP) is an Internet protocol used for the transfer of accurate time, providing time information along so that a precise time can be obtained

To enable the Network Time Protocol; NTPserver, locate and click:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpServer

In the right pane, right-click Enabled, then click Modify.

In the Edit DWord Value box, type 1 under Value data, then click OK.

Now go back and click on

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParametersNtpServer

In the right pane, right-click NtpServer, then Modify, in the Edit DWORD Value under Value Data type In the right pane, right-click NtpServer, then Modify, in the Edit DWORD Value under Value Data type the Domain Name System (DNS), each DNS must be unique and you must append 0×1 to the end of each DNS name otherwise changes will not take effect.

Now click Ok.

Locate and click the following

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpClientSpecialPollInterval

In the right pane, right-click SpecialPollInterval, then click Modify.

In the Edit DWORD Value box, under Value Data, type the number of seconds you want for each poll, ie 900 will poll every 15 minutes, then click OK.

To configure the time correction settings, locate:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Timeconfig

In the right pane, right-click MaxPosPhaseCorrection, then Modify, in the Edit DWORD Value box, under Base, click Decimal, under Value Data, type a time in seconds such as 3600 (an hour) then click OK.

Now go back and click:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Timeconfig

In the right pane, right-click MaxNegPhaseCorrection, then Modify.

In the Edit DWORD box under base, click Decimal, under value data type the time in seconds you want to poll such as 3600 (polls in one hour)

Exit Registry Editor

Now to restart windows time service, click Start, Run (or alternatively use the command prompt facility) and type:

net stop w32time && net start w32time

And on each computer, other than the time server, type:

W32tm/ -s

And that’s it your time server should be now up and running.

Copyright 2008 © Richard N Williams
Richard N Williams is a technical author and a specialist in the telecommunications and network time synchronisation industry helping to develop dedicated time server products; ethernet clocks, GPS time servers, NTP servers, digital wall clocks, atomic clock servers and SNTP time servers. Please visit for more information about NTP products and NTP servers This article may be republished and reprinted in its complete form or in part without seeking permission providing a relevant link to this site is maintained. It is a violation of copyright law to reprint or publish this content without following these terms.

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