In a blog post posted on November 21, 2022, Meta, parent company of Facebook, explains that it wants to transform the synchronization protocol of its global servers to improve the experience of Internet users.
Nanosecond synchronization
Most Internet-connected devices today use Network Time Protocol (NTP) to synchronize their internal clock. This synchronization between servers — and between machines accessing them — is essential to allow computers to simultaneously display the desired information. Anyone who has ever played an online game with a poor connection knows that the experience is severely degraded, because the longer it takes for information to reach a server, the longer it takes to execute.
More banal, sending an instant message is very dependent on good synchronization. “Think of something as common as sending a message on Messenger. Thanks to network synchronization, someone can send a message to a friend on the other side of the world and see it appear in real time. This cannot happen if the synchronization between the servers is not correct”, points Meta. Facebook and the latter will therefore switch to a new synchronization protocol, called PTP (Precision Time Protocol).
PTP has a major advantage over NTP. It is indeed able to synchronize different machines with a precision close to the nanosecond (one millionth of a second), where the NTP is limited to the millisecond (one thousandth of a second). “Functions such as messaging, video conferencing, online gaming and even updating or deleting content rely on exact synchronization between multiple servers, sometimes even between multiple data centersexplain Ahmad Byagowi and Oleg Obleukhov, two Facebook engineers. The more servers, the greater the synchronization. If a single server is out of sync with the others, it can cause noticeable slowdowns and errors.”
Displaying the right information at the right time is critical for a company such as Facebook, particularly in the metaverse that the firm of Marc Zuckerberg has been struggling to build for a year. When all servers are synchronized, interactions are smoother, more natural and therefore seem more “real”. “The PTP will benefit current products and services, and will be a fundamental technology for the development of the metaverse”, says the Facebook blog post. The PTP protocol is not perfect (no protocol can be), but thanks to an accurate measurement of network latency, it is able to compensate for this delay by adding a few nanoseconds to the time of sending a packet on the network.
This protocol devised in 2001 is now widely used by network operators, who are very concerned about synchronization. But rolling it out across Facebook is a challenge, as the company has servers to sync all over the world. The company therefore had to thoroughly review the operation of its network to operate the switch. Good news, the work of the Meta teams is available in open source. Let’s hope that with its upcoming adoption, video calls will no longer be a festival of speakers who cut each other off.