what is Stratum in Linux?
Posted by Jon Snow on April 13th 2018 11:51 AM
NTP uses the concept of stratum to define the hierarchy of NTP service, Stratum is simply a layer of network that is used to distribute accurate time across a network of devices. These layers are named by 'Stratum 0', 'Stratum 1', 'Stratum 2' and etc. At the top of the hierarchy is 'Stratum 0' time servers. Stratum 0 time serves get their time from a reference time source such as cesium atomic clock or a Global Positioning System(GPS). In additional stratum 0 time server, we also have stratum 1 time server. Stratum 1 time server is directly linked to a reliable source of UTC time such as GPS or CDMA i.e. 'Stratum 0' and gets their time from stratum 0. Stratum 1 time server acts as a primary network time standard and distributes time to other devices on the network. Similarly stratum 2 gets their time from stratum 1 time provider and can continues down to NTP stratum level 16. Stratum 0 are not publicly available, they are on the internet but you are not allowed to access them. Stratum 1 are publicly accessible NTP time providers on the internet and you can configure your system to connect to these system to get your time. As lower dower the hierarchy you go the less accurate the time provider become and below 16 stratum levels, the less precise devices become. But, to combat inaccuracies and to make the stratum more dependable, each client can acquire time from multiple servers. Additionally, stratum 2 devices and below can be coordinated with each other. Stratum 1 devices can also be peered, for instance, NTS 6001 GPS time server devices.The stratum chain is predominantly used across large computer networks. This is because blitzing a solitary stratum 1 time server with multiple NTP requests, from hundreds of machines, will result in system overload or simply block the network.The outcome of such a scenario is that computers, routers and any other devices connected to the network will frequently be waiting for time synchronization requests to be processed.