Time synchronisation is a critical aspect to modern computing, especially when computers are on a network or need to communicate with other networked machines.
Timestamps are crucial for computers to acknowledge when an event occurred and it is the only information they have to ascertain if an event has occurred. Without accurate time stamps the consequences can include:
• Loss of data
• Difficult to log errors
• Difficult to debug
• Failure to save
• Time sensitive applications may fail
Modern operating systems like Windows 7 have automatic synchronisation software already installed. W32Time has been a part of Microsoft’s different generations of operating systems for some time but in Windows 7 it is set to be automatically on (Rather than the user having to set it) – synchronising your PC straight out of the box.
With such NTP (Network Time Protocol) based synchronisation available by using internet time servers (normally Microsoft and NIST) many people may wonder if a dedicated time server is still required.
Problems with Internet Time Servers
There are several drawbacks to using this Internet time as a source of UTC (Coordinated Universal Time – the global timescale often referred to as GMT).
The first and most important drawback to internet time servers is their location through the firewall. Having to rely on a source of time across the internet means keeping the TCP port open – a crucial security weakness that can be used by malicious users or bots.
Another downside to internet time servers is their lack of guaranteed accuracy. While places like NIST (National Institute for Standards and Time) and Microsoft have reliable and accurate time servers – the accuracy can be dependent on how far away you are peering from. And many other time servers available as a source of internet time are less reliable – and as NTP can’t authenticate a time signal from across the internet – it can be difficult to assess.
Benefits of an External NTP Server
Dedicated external NTP servers are far more secure. They receive their tie from GPS satellites of Long Wave transmissions so the signals can’t be intercepted by computer hackers or malicious software. Also, NTP can authenticate the signals ensuring you know where they are coming from and how accurate they are.
With time being so important on modern networked computers, taking a risk with internet time may cost a lot more than any minor investment in a dedicated NTP time server.