NTS-200 Network Time Server
By Biju Oommen

Time keeping and synchronization are so very important with all those automatic processes we take for granted such as archiving, directory synchronization, cron jobs, time stamping files, auditing and monitoring, scheduled operations, email and transactions etc. All these and more are based on the premise that we have the correct time, but we know computer clocks are notorious for drifting and losing seconds if not minutes and hours.

The NTS-200 derives accurate time directly from atomic clocks aboard global positioning system (GPS) satellites. It uses an integrated, 12-channel GPS receiver to track and maintain accurate and reliable time from these satellites passing overhead.

We found that the NTS-200 was a very good Stratum-1 time source that sits on the network and provides clock synchronization to clocks on servers, workstations, communication servers etc across entire enterprise networks. The basic definition of a stratum-1 timeserver is that it is directly linked (not over a network path) to a reliable source of UTC time, i.e. a GPS satellite. If needs be it can also connect to other NTP servers as a back up to the GPS unit failure or when GPS reference signal is not available. This is known as a Stratum-2 time source.

A wide range of network protocols are supported and the device lends itself to easy and comprehensive management. The flash memory allows for new features via software upgrades and the web-based status and control interface is another plus, as is the ability to lock the front Keypad control panel.

The manufacturer has provided on the web interface control pages that are password protected and HTTP and FTP access can be disabled to secure the unit. Telnet access status/control are also password protected and can be disabled too if necessary.

On the front panel the LED indicates normal operation and alarms. The front panel alphanumeric backlit LCD display coupled with the directional keypad push buttons help administrators perform simple monitoring and configuration changes right in the wiring closet or computer room.

First we mounted the GPS antenna on the roof at a location where the antenna had a clear view of the sky so that it can track the maximum number of satellites. Then we ran a cable from the antenna to the NTS-200. It must be noted that antenna cable runs of more than 45m may need a GPS antenna in-line amplifier and to drive even further say up to 457m you may need a GPS antenna down/up converter to make sure there is a proper signal getting through to the unit. Of course, different buildings and environments can make this job either very easy or extremely difficult.

While mounting on a roof is the best option for accurate time keeping, the NTS-200 also features single satellite timing. Which means in environments where satellite visibility is limited the server can keep accurate time just by tracking one satellite at a time. This is especially useful when the only option is to install the antenna is a window with a limited view of the sky.

The NTS-200 was rack mounted and then connected via the Dual-speed Ethernet port to our test Lan. Using the front panel we entered IP address parameters etc and left the "Display Security" option off. Within a few minutes the NTS-200 was up and running and ready to go. Next we pointed NTP clients to the appliance, which provides IP network time synchronization over the Ethernet via NTP.

The front panel display displays useful information regarding the state of the appliance. The web access option is also very handy for remote operation and control.

The remote administration and management of the security features were very good and multi-faceted. A good amount of choice i.e. Telnet, Web access, Serial access using windows HyperTerminal through the utility port and not to forget the front panel access through the backlit LCD display coupled with the directional keypad push-buttons.

The user manual is good and is clear, legible and well laid out. However we would like to see more detailed information on GPS antenna in-line amplifier and GPS antenna down/up converter options. An added bonus would be the inclusion of various Client setup scenarios explained with illustrations.

The increased use of digital signatures, time stamping and ever increasing need for improved network log file accuracy mean that the importance of network timekeeping will only grow.

Geographically disparate systems on heterogeneous networks, network forensics and all manner of intrusion detection and prevention systems need to accurately relate data to each other at the correct time in order to be effective and admissible as evidence in any criminal investigation.

The key to all this to remember that sometimes for such a potentially dangerous issue, there is available a simple, effective, and easy solution.

The NTS-200 Network Time Server is a true plug and play appliance. Especially when hard-pressed systems administrators have little time to do anything other than keep the network up and running. We found the device to be a cost-effective purchase and it helped avoid the pitfalls of time related operational or security mishaps. We would consider the device is a serious candidate for keeping accurate time and ensuring data integrity.