Network Time Protocol (NTP) is a UDP protocol that provides a reliable way of transmitting and receiving the time over TCP/IP networks. It has become the de facto standard for synchronizing Internet computers and other networked devices to Universal Coordinated Time (UTC).  The Internet Engineering Task Force formalized NTP in RFC 1305.

For a complete time synchronization solution client software is required to read the NTP packets generated by an NTP time server and synchronize the local clock. (see "How do I configure NTP clients" on the GPS Time Servers FAQ page)

Simple Network Time Protocol (SNTP) is a simplified version of NTP, which is used in cases where a full implementation of NTP is not required. Because SNTP uses the same packet format as NTP, SNTP clients can utilize NTP servers. (SNTP is defined in RFCs 1361,2030 & 4330.)

Power over Ethernet (PoE) is a standard-based technology for safe delivery of data and power to remote devices over Cat 5e or Cat 6 copper cabling.  So both Power and Data can co-exist on the same copper conductors.  This allows you to install an end-device where there is no local power.

Benefits of PoE

Cost Savings:

• No need to install power outlets.
• No need to hire a licensed electrician to install.
• Reduce cabling cost.
• Use existing Cat5/Cat6 cable already installed in buildings.

Safety

• Designed to protect equipment from electrical overload under-powering or incorrect installation.
• If there is damage to a cable, the power is stopped - no sparking or fires.

Flexibility

• Install end-device where there is no local power.
• Easily install devices wherever there is an ethernet cable.

Functionality

• Can be backed up by an uninterruptable power supply (UPS).

Cost Savings using a Synchronized Display Clocks

Anytime there are multiple shift changes and alternating break times throughout any given workday, you need to coordinate your employees, and everyone is on the same time.  Synchronized clocks allow everyone to see the same time and you can add features like a countdown timer between shift changes and/or break times, which can keep employees aware of the elapsed time throughout the day.

What are your cost savings?

Other Savings

• Clocks adjust automatically for Daylight Savings Time
• Clocks re-adjust automatically after a power outage

Internal clocks in electronic devices are not designed for accuracy and can drift more than one hour in a year. To correct for this, you can employ network time synchronization solution.

Time synchronization is an important criteria for efficient network operations. A network time synchronization implementation is simple and relies on a network time server.  The characteristics of a network time server determine the security, reliability, and accuracy as well as the ease of manageability of the network time application.

Characteristics of a secure, reliable and accurate network time synchronization application:

• Network time synchronization occurs between servers and clients via network time protocol (NTP).
• A master time source known as an NTP time server is used to time synchronize a network.
• The time server must be behind the firewall for security.
• A stratum-1 time server is directly traceable to national standards for accuracy; typically through GPS transmissions.
• The time server must be available and accurate 24/7 for reliability.
• A hardware time server appliance greatly improves the manageability of the network.

As a general rule, it’s wise to have an internal time server on your network to support your PoE clocks. This is particularly true if you are deploying a number of PoE clocks. Here are some reasons why this is important:

• If you have a large number of clocks independently referencing the same external time server, you may possibly run afoul of the external time server’s network access policy (by accessing the time server more frequently than its open access policy allows).
• An internal time server reduces Internet traffic and helps secure timekeeping on the network.
• Secure timekeeping on the network is important because opening your network to NTP (port 123) traffic allows for the possibility of these types of hacker intrusions:
• Sending too much data in the NTP packet, thus causing the NTP service to become overloaded and resulting in a denial of time services attack.
• Sending specially constructed packets that essentially “take over” machines within your network (by using the same privileges as the NTP service running on those machines) and, in so doing, allowing the intruder to mask the break-in by resetting the time on those machines, making it impossible to effectively reconstruct the exact sequence of events that lead to the break-in.
• By deploying your own internal time server, which alone references an external stratum 0 time source like GPS, you can construct the most robust form of NTP architecture for the PoE clocks on your network. You can also minimize the amount of network management required to accomplish the goal of secure and accurate timekeeping.