Time synchronization is critical in computer networks because planning, managing, debugging, and protecting a network all involve establishing when an event has occurred and require accurate time. However, it is difficult to maintain an exact time because the computer clock drifts a few minutes or seconds per day.
Therefore, routers, servers, devices and switches use Network Time Protocol (NTP) to solve the problem of network time synchronization. But why is NTP important and how does it work?
What is Network Time Protocol?
Network Time Protocol is an online protocol that synchronizes computer clock times in a network to within milliseconds of UTC, allowing devices connected to a TCP/IP network to operate at the same adjusted time. This includes protocol and client-server programs for computers. It is very effective in correcting server transmission errors and is the basis for time synchronization across networks.
NTP was first developed by Dave Mills in 1985 at the University of Delaware, but today the protocol is open-source and used worldwide.
How does the Network Time Protocol work?
NTP follows a three-step process to synchronize time:
- The protocol client requests an exchange with the time server.
- The client calculates its delay/lag and readjusts to match the server clock.
- There must be six time swaps within 10 minutes to update the clock every 10 minutes (or sometimes every hour) to maintain its hourly accuracy. Messages transact updates through User Datagram Protocol (UDP)—port 123.
What are stratum levels?
The Coordinated Universal Time (UTC) source has degrees of separation called strata, which follow a strict hierarchy.
- Layer 0: This is the ground clock that receives the true UTC from the satellite system designed specifically to transmit this “real time”. For this reason, the clocks in stratum 0 are the origin and reference clocks for all clocks. Examples are the atomic clock and the GPS clock.
- Layer 1: These are computer devices/systems directly connected to Stratum 0 to receive the actual time.
- Layer 2: These time servers get their real time from Stratum 1.
- Layer 3: These computing devices are connected to Stratum 2 servers and obtain their real time from Stratum 2 servers.
The NTP hierarchy continues through the ranks, and time accuracy is reduced as it progresses through the ranks. There are a total of 16 strata in the NTP hierarchy; layer 16 indicates an unsynchronized device.
It is important to consider Segal’s Law when installing a time server for a network:
A man with a watch knows what time it is. A man with two watches is never safe.
Based on this law, maintaining two NTP servers makes it difficult for hackers to decide which one is genuine. Although it is better to choose two servers from stratum 0 because of their high accuracy, a combined stratum 0 and stratum 1 server will also serve effectively.
Network Time Protocol Features
NTP has several features, but these are the two most important features:
- UTC: NTP uses UTC to synchronize time, and this synchronized time is then made available over a network. UTC can distribute over networks using time servers.
- Time servers: Some computers specialize in time synchronization and are called “time servers”. Time servers are specialized because it is impractical to equip all computers with receivers that can access atomic and GPS clocks to receive and transmit time over a network.
Other features of note include NTP’s ability to resolve or adjust errors in server information exchange, regardless of the severity of the fault or vulnerability. Secondly, it is very consistent and reliable in timing, which makes it a valuable asset for organizations that need the time synchronization element to operate successfully. These organizations include transportation/traffic control systems, such as those of trains and airplanes, hospitals, financial institutions, and security organizations.
Why NTP and time synchronization are important
Minute time gaps between devices could lead to chaos. Accuracy is not a luxury but a very important and valuable necessity. While there are several scenarios in which this happens, here are a few that show the importance of NTP.
Security systems rely on synchronized time to prevent crime and combat it if it occurs. For example, devices such as security cameras work with timestamps to record events in real time, making it much easier to track evidence and solve a crime. Time synchronization is a valuable asset for optimal security.
2. Log Timestamps
Files, such as software applications, are timestamped for warranties and carry expiration dates or update schedules based on when they are installed on a computer.
Synchronized time ensures that these coded instructions in applications are followed. This rule also applies to automatic file system updates and bug fixes designed for maintenance that may occur on a network of computers at a fixed time.
3. Order in time-dependent operations
The nature of projects with procedures is that they require sequential steps to accomplish them. Some or all of the steps may be time sensitive, and synchronized time is very relevant to success, where procedures are distributed to different team members working on the same project.
4. Messaging and telecommunications
Timestamps are very relevant in things like emails, text messages, and delivery reports, depending on the circumstances. NTP is also very useful in telecommunication and broadcast settings.
NTP and time synchronization are very helpful in troubleshooting network issues.
6. Brings accuracy and precision
Some medical procedures are timed and use timed medical equipment for precision and accuracy. The presence or absence of synchronized time could mean the difference between life and death.
7. Time value in the real world
Although NTP is not directly responsible for regional time zones, synchronized time is the reason regional clocks can operate relative to Coordinated Universal Time (UTC). For example, the local time in Lagos is different from the local time in Tokyo. However, we can maintain accurate time differences across regions because synchronized time is functional.
8. Traffic control
Delicate infrastructure like trains or air traffic control rely heavily on synchronized time to prevent collision accidents through timed switching of rails (for trains) and giving instructions from air traffic control towers to land planes safely.
9. Analysis and Audit
It is only possible to perform a credible audit or forensic analysis of any kind with the intervention of synchronized time.
10. Accurate time
Automatic time synchronization makes things easier for many device users, as only some are savvy enough to manually configure their time setting to accurately and accurately reflect real time.
Network Time Protocol is Vital to the Internet
Network Time Protocol is an online protocol that helps computers communicate and synchronize time over data networks. Since its genesis in 1985, it has undergone several evolutions, in particular by integrating stratum levels. With recent advancements in technology, we will see the application of NTP in the metaverse and Web3 space in no time, as the application of NTP knows no bounds.