To serve their functions efficiently and safely, hospitals and care facilities must correctly synchronize all elements of the network. This is why, as a telecommunications engineer, you need to know the different types of NTP you can implement.
A sector as critical as healthcare requires ultraprecise coordination. At this point, having software that integrates all systems or an NTP protocol that synchronizes clocks makes a big difference. It’s no coincidence that those responsible for healthcare communications are extremely meticulous when choosing such tools.
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What is NTP?
NTP (Network Time Protocol) is a time-synchronization protocol that allows the clocks of various computer systems to be coordinated so they function correctly. This way, the entire network of devices (computers, servers, phones, switches, firewalls, etc.) will share the same time.
Of course, Network Time Protocol is not the only Internet protocol that allows us to synchronize the clocks of computer systems. Other protocols that also fulfill this function include Simple Network Time Protocol (SNTP) and Precision Time Protocol (PTP). What is certain is that NTP is the most established (it was created in 1981 and is now in its fourth version), and it is widely used in railways, hospitals, universities, and IT networks.
How does NTP work?
Protocols are sets of rules that connected devices (clients) must follow when communicating with each other. In the case of NTP, these shared rules relate to time. When devices need to know what time it is, they query an NTP server, which in turn obtains this information from an atomic clock (UTC).
All types of NTP use the UDP protocol on port 123, both at the source and at the destination.
Client–server communication is based on a sequence of requests and responses:
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The client sends an NTP request to the server and timestamps when it does so.
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The server timestamps the moment it receives the request.
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The server issues the response and timestamps when it sends it.
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The client timestamps the moment it receives the response.
The fact that this process takes a few microseconds does not cause any desynchronization. The device can determine how much delay the response took and recalibrate its internal clock.
When the network is very complex and contains many integrated devices, servers and clients are organized hierarchically. This is a system of levels or strata that operates in a pyramid-like structure.
What are the benefits of using NTP?
Popular
The existence of various types of NTP gives this protocol great versatility. This is why it is the most widely used time-synchronization protocol, not only in industrial environments but also in home networks. It is worth highlighting its high level of compatibility with all types of devices and operating systems.
Precise
When it comes to time synchronization, Network Time Protocol provides devices with a high degree of accuracy. It only takes a few milliseconds to achieve synchronization. Even when there are network delays or time offsets, it still delivers excellent precision.
Scalable
The NTP protocol can be applied to any network regardless of size. In fact, it performs particularly well in highly complex networks. As mentioned earlier, it can efficiently handle large volumes of requests through its tiered (stratum-based) structure.
Flexible
Customization is one of the greatest strengths of Network Time Protocol. Not surprisingly, its source code is open-access. Users can employ multiple time sources and choose between various stratum levels to reinforce accuracy.
This protocol is especially useful when synchronizing time across different time zones. This is very convenient for industries with an international presence.
Types of NTP
Networks that use this protocol have different ways of implementing time synchronization. Thus, NTP types allow us to classify the protocol based on its ownership (public/local) or on how it distributes information (unicast / multicast).
Types of NTP by ownership: public and local
| Public | Local | |
|
Ownership and management |
Third-party | Client-owned |
| Security | Low (requires an open port on the firewall) | High (keeps the firewall “closed”) |
|
Synchronization depends on Internet connection |
Yes | No |
|
Risk of overload |
Yes, due to shared use | No, because it is used only by the client |
|
Delays in receiving information |
Possible | Minimal |
|
Limitations on usage time and number of clients |
Yes | No |
NTP unicast and multicast
| Unicast | Multicast | |
| Time reception (regular) / time zone information (optional) | The slave clock queries the master clock. | The master clock sends it to a group address so that slave clocks can receive it automatically. |
| Type of communication | Unidirectional | Bidirectional |
| IP address of the slave clock | Each slave clock has its own (assigned by a DHCP server or network administrator). | No need for IP address management or assignment. |
| Network overload | Practically none (one packet reaches the entire group). | Significantly higher than unicast. |
| Do network delays affect the accuracy of slave clocks? | Yes (WLAN/LAN changes: up to 100 ms possible). | No, as long as the networks are symmetrical (execution time can be compensated). |
| How packets are sent | Through network limits (router) via IGMP. | Through network limits (router). |
Knowing the different types of NTP is only the first step — you still need to choose a solution that meets your needs. At Advantecnia, we offer you AdvantClock: the latest in time synchronization and industrial clock systems via GPS. Implement it now in your hospital, care facility, or healthcare center by getting in contact with us.
