NTP Solutions Intro to the NTP solution set 5/9/2018 NTP Solutions Intro to the NTP solution set

What are Network Time Servers? 5/9/2018 What are Network Time Servers? What are Network Time Servers used for? Synchronizing computers and other clients over a network using Network Time Protocol (NTP) In full NTP mode an NTP timeserver does not create traffic, it responds to time packet requests from clients Our NTP servers use GPS or Time Codes as sources of synchronization Ease of use plug & play = set & forget

What is NTP? NTP = Network Time Protocol 5/9/2018 What is NTP? NTP = Network Time Protocol It is an Internet Protocol developed by Professor David L. Mills of the University of Delaware during the 1980s It requires a reference clock source It uses UTC as its reference timescale Uses an Intersection Algorithm NTPv3 is still the official version of NTP NTPv0 developed in 1985 in both Fuzzball and UNIX OS NTPv1 released in 1988 as RFC 1059 NTPv2 released in 1989 – RFC 1119 published In 1992, RFC 1305 defined NTPv3. In 2010, RFC 5905 was published containing a proposed specification for NTPv4. Harlan Stenn – now leads the open source project following retirement of David Mills.

How Does it Work? Hardware Server with Software Client 5/9/2018 How Does it Work? Hardware Server with Software Client Client selects “best” time source from list of servers Client polls chosen servers at regular intervals to request time of day (TOD) packet Client calculates round trip delay from receipt time of TOD packet Client estimates UTC offset and updates its internal time base Clock synchronization algorithm A typical NTP client will regularly poll three or more servers on diverse networks. To synchronize its clock, the client must compute their time offset and round-trip delay. Time offset θ is defined by θ = ( t 1 − t 0 ) + ( t 2 − t 3 ) 2 {\displaystyle \theta ={(t_{1}-t_{0})+(t_{2}-t_{3}) \over 2}} , and the round-trip delay δ by δ = ( t 3 − t 0 ) − ( t 2 − t 1 ) {\displaystyle \delta ={(t_{3}-t_{0})-(t_{2}-t_{1})}} , where t0 is the client's timestamp of the request packet transmission, t1 is the server's timestamp of the request packet reception, t2 is the server's timestamp of the response packet transmission and t3 is the client's timestamp of the response packet reception.[1]:19 The values for θ and δ are passed through filters and subjected to statistical analysis. Outliers are discarded and an estimate of time offset is derived from the best three remaining candidates. The clock frequency is then adjusted to reduce the offset gradually, creating a feedback loop.[1]:20 The synchronization is correct when both the incoming and outgoing routes between the client and the server have symmetrical nominal delay. If the routes do not have a common nominal delay, there will be a systematic bias of half the difference between the forward and backward travel times.[17]

How do the Clients select the Servers? 5/9/2018 How do the Clients select the Servers? Time Servers are rated in Stratum levels: Stratum 0 sources are Primary Reference clocks such as Cesium or GPS Clocks that cannot be connected directly to a network Stratum 1 sources derive time directly from Stratum 0 sources (Such as GPS Disciplined Oscillators) Stratum 2 sources derive time from Stratum 1 sources e.g. via a time code Stratum 3 sources derive time from Stratum 2 sources etc. etc. If a timeserver is unsynchronised it is rated as Stratum 16 Stratum 0 These are high-precision timekeeping devices such as atomic clocks, GPS or other radio clocks. They generate a very accurate pulse per second signal that triggers an interrupt and timestamp on a connected computer. Stratum 0 devices are also known as reference clocks. Stratum 1 These are computers whose system time is synchronized to within a few microseconds of their attached stratum 0 devices. Stratum 1 servers may peer with other stratum 1 servers for sanity check and backup.[13] They are also referred to as primary time servers.[2][3] Stratum 2 These are computers that are synchronized over a network to stratum 1 servers. Often a stratum 2 computer will query several stratum 1 servers. Stratum 2 computers may also peer with other stratum 2 computers to provide more stable and robust time for all devices in the peer group. Stratum 3 These are computers that are synchronized to stratum 2 servers. They employ the same algorithms for peering and data sampling as stratum 2, and can themselves act as servers for stratum 4 computers, and so on. The upper limit for stratum is 15; stratum 16 is used to indicate that a device is unsynchronized. The NTP algorithms on each computer interact to construct a Bellman-Ford shortest-path spanning tree, to minimize the accumulated round-trip delay to the stratum 1 servers for all the clients.[1]:20

Other Timeserver Protocols 5/9/2018 Other Timeserver Protocols SNTP – A simplified version of NTP that doesn’t include the delay compensation algorithm Broadcast or Multicast NTP - clients passively listen to time updates after an initial round-trip calibrating exchange Daytime & Time protocols – used for recording the time of events

What does NTPv4 do for you? 5/9/2018 What does NTPv4 do for you? Use of floating-point arithmetic instead of fixed-point arithmetic. Redesigned clock discipline algorithm that improves accuracy, handling of network jitter, and polling intervals. Support for the nanokernel kernel implementation that provides nanosecond precision as well as improved algorithms. Public-Key cryptography known as autokey that avoids having common secret keys. Automatic server discovery (manycast mode) Fast synchronization at startup and after network failures (burst mode) New and revised drivers for reference clocks Support for new platforms and operating systems

Accuracy and Capacity NTP is a nondeterministic time format 5/9/2018 Accuracy and Capacity NTP is a nondeterministic time format Dependent upon network symmetry and oscillator accuracy Network traffic or traffic loading is also a factor Internal oscillator – the more accurate the clock (Oscillator) in the client the longer it can go between updates and the greater the accuracy between those updates. Typical Performance Internet ~100ms LAN ~1-5ms Note that NTP is designed to produce very little network traffic, so almost any server can service thousands of clients. Server capacity is normally more about specmanship than actual need

5/9/2018 Why use NTP? Basic synchronization of all network compatible appliances on the network Audit trails:- logging time of events or actions Legal time requirements – time stamping events that may later be relied upon in litigation Time stamping of financial transactions or stock buying/selling Time stamping of events or actions for safety purposes NTP provides a low-cost solution to all of these applications

But NTP is Free from the Internet - why buy your own timeserver? 5/9/2018 But NTP is Free from the Internet - why buy your own timeserver? Security. Opening the NTP port on a company firewall adds to vulnerability Management Having your own server allows it to be managed Traceability Using the internet makes it harder to show traceability of a time source to UTC

5/9/2018 NTP Server Overview Almost every product that Brandywine make that has an Ethernet port includes the NTP server function Some products are primarily designed as NTP Servers Other products are focused on other functions, but NTP is included as a utility Modular products can be configured with multiple NTP server ports and include and other functions

Stand – alone NTP Timeservers 5/9/2018 Stand – alone NTP Timeservers

NTV-100xG & IDC-100 Low cost, entry level products 5/9/2018 NTV-100xG & IDC-100 Low cost, entry level products 100 BaseT Ethernet NTPv3 NTV100 = GPS Ref - Rack Mount “RG”- Desktop “DG” IDC-100 = IRIG B Ref Web Page management Simple crystal, oscillator

NTP80plus GPS Synchronized 3 independent Ethernet Ports 5/9/2018 NTP80plus GPS Synchronized Peer to Peer Capability Long antenna cable length option available. 3 independent Ethernet Ports 100 BaseT Ethernet Interface NTP V3/V4 Internal Oscillator choices – Rb, OCXO & TCXO (std) 1PPS on time output

ENTA-II GPS and IRIG B Synchronization (user configured) 5/9/2018 ENTA-II GPS and IRIG B Synchronization (user configured) Dual 100baseT Ethernet Ports High stability OCXO as standard Additional I/O (IRIG, Have Quick, 5x user programmable serial, analog clock driver) UL listed

See “Brandywine Future Products” for details 5/9/2018 NTP800 Next Generation Utility NTP Timeserver 4 x Gb Ethernet Ports GNSS Capability Timecode Input Dual Power Supplies – front loaded 1PPS, 10MHz, Timecode & Serial outputs See “Brandywine Future Products” for details

Modular Systems with NTP 5/9/2018 Modular Systems with NTP

Modular Master Clock (MMC) 5/9/2018 Modular Master Clock (MMC) 2U or 1 U Versions (5 or 12 User Slots) Redundant Power, Master Clock Modules available Dual Port NTP OSM Ethernet 100BaseT NTPv3 (RFC-1305) NTPv4 (RFC-5905) Authentication: SHA-1, MD5 Hot-swappable modules

M210 and M211 Multiple Input Options Multiple Output Options 5/9/2018 M210 and M211 M210 Modular Timing System Multiple Input Options Multiple Output Options 3 Module Slots Peer-to-Peer NTP capability 3 Port100BaseT Ethernet option High level of intrinsic security M211 Modular Timing System 9-slot version of M210 Talk about security aspects of M211 and M210 multi module applications.

See “Introducing the M212” Cut-down version of MMC No hot-swap capability Shorter chassis depth Commercial/Industrial specification See “Introducing the M212”

Board Level NTP Timeserver

PCIe-5905 GNSS, IRIGB, Have Quick/1PPS standard OCXO standard 1Gb Ethernet port Host setup via Web Page NTPv4 timeserver

Other products with NTP capability

NFS-220/NFS-220plus GPS Synchronised HQ/1PPS Reference Inputs OCXO & Rubidium oscillators Multiple 1PPS & 10MHz Outputs Multipurpose (Workhorse) Product Single 10BaseT Ethernet port (NTPv3) CE/AS/NZ Certified

FRU & TRU Satcom and other applications Options for vibration isolated low noise OCXO 10x10 MHZ outputs with high isolation <100dB 2 independent 100BaseT Ethernet ports (NTPv3) SAASM option

Precision Time System (PTS) GPS or HQ/1PPS Synchronization Rb oscillator 10MHZ, IRIG B, HQ,1PPS outputs Single 100BaseT Ethernet port (NTPv3) Dual redundant Capability SAASM option

Portable Timing Unit (PTU) GPS Synchronization 115VAC/Battery operated Single 100BaseT Ethernet ports (NTPv3) Portable

RTG-510 GPS Synchronized 20 programmable outputs for time code and pulse rates Supports IRIG A, B, E, G, NASA36, HQ and 1PPS Electrical and optical time code input and outputs High stability OCXO Dual independent 100BaseT NTP ports (NTPv3) Redundant hot swappable power supplies

Product NTP Ports NTPv Base-T GNSS Timecode Input Oscillator Peer-to-Peer Authentication Other Outputs Other Features Height Dedicated NTP Timeservers NTV-100RG 1 3 100 GPS No Crystal None   Desktop Option 1U IDC-100 IRIG-B NTP80plus 3/4 Yes Option TCXO/OCXO/Rb 1PPS NTP800 4 1Gb Multiple Inputs TCXO/OCXO/Rb/CSAC MD5, SHA-1 Multiple Outputs ENTA-II 2 OCXO Bus-level Solutions PCIe-5905 1000 IRIG-B/HQ Modular Platforms M210 1-6 Any Intrinsically secure M211 1-24 3U M212 2-26 SBAS OCXO/Rb MMC 3U 2-12 2U MMC 1U Other Products with NTP Capability NFS-220/Plus 10 HQ/1PPS TRU/FRU PTS Rb PTU RTG-510

Summary We have a range of NTP Timeservers to suit all applications and pockets We provide unrivalled security features in certain platforms NTP is seen as a utility across the product range Watch out for specmanship from competitors