Technical Information Operating Instructions M300 / GPS
Contact Information Meinberg Funkuhren GmbH & Co. KG Lange Wand 9 D-31812 Bad Pyrmont Telephone: +49 (0) 52 81 / 9309-0 Telefax: +49 (0) 52 81 / 9309-30 Internet: http://www.meinberg.de E-Mail: info@meinberg.de Bad Pyrmont, 16.
Table of Contents Quick Start..................................................................................................................... 8 Network Timeserver with GPS synchronized time base............................................... 9 The Modular System LANTIME.................................................................................10 Supported Network Services................................................................................12 Additional Features and Options.............
Setup Time Zone of Serial Outputs..................................................................... 30 Menu: Time Service.................................................................................................32 Menu: external NTP.............................................................................................32 Menu: Stratum of local clock...............................................................................32 Menu: Restart NTP...............................................
Configuration: Security............................................................................................58 Password.............................................................................................................. 59 HTTP Access Control.......................................................................................... 59 SSH Secure Shell Login.......................................................................................60 Generate SSL Certificate for HTTPS ............
SNMP Support.............................................................................................................99 Configuration over SNMP .................................................................................... 101 Examples for the usage of the SNMP configuration features............................ 102 Further configuration possibilities..................................................................... 104 Send special timeserver commands with SNMP..................................
Time Strings...........................................................................................................130 Format of the Meinberg Standard Time String..................................................130 Format of the GPS Capture String..................................................................... 131 Format of the SAT-Time String.........................................................................132 Format of the Uni Erlangen String (NTP) ........................................
Quick Start When booting the system the following message will be displayed while dots will be counted up in the lower line:. MEINBERG TIMESERVER ....... please wait... Main Menu will be displayed with some important status informations after booting has finished: GPS: NORMAL OPERATION NTP: Offset PPS: -50us Mon, 28.08.
Network Timeserver with GPS synchronized time base LANTIME (Local Area Network Timeserver) provides a high precision time base to a TCP/IP network (Stratum-1-Server). The NTP (Network Time Protocol) is used to synchronize all NTP clients with the reference. The several LANTIME variants differ from each other by the time reference. A GPS receiver, a DCF77 receiver or an IRIG time code receiver can be integrated as an internal reference as well as a combination of these references (hybrid system).
The Modular System LANTIME LANTIME M300 is a set of equipment composed of a reference clock (e.g.: satellite controlled clock GPS170 or Time Code Receiver TCR5xx), a single-board computer SBC LX800 500 MHz with integrated network card, and a power supply unit NLP65, all installed in a metal desktop case and ready to operate. The interfaces provided by LANTIME are accessible via connectors in the rear panel of the case. Details of the components are described below.
The implemented NTPD distributes the reference time from the GPS receiver cyclic in the network. Information on the NTPD is monitored on the LC display or can be inquired via the network. The installation of LANTIME is very easy for the system/network administrator. The network address, the netmask and the default gateway have to be configured from the front panel of LANTIME. The network address or the equivalent name of LANTIME has to be shown to all NTP clients in the TCP/IP network.
Supported Network Services The following network services are provided via RJ45 10/100Base-T Ethernet (Auto sensing): - NTP v2, v3, v4 - NTP broadcast mode - NTP multicast - NTP symmetric keys - NTP Autokey - Simple Network Time Protocol (SNTP) - TIME - SNMP v1,2,3 with extended SNMP-Agent and SNMP-Traps for NTP and reference clock status - DHCP Client - NFS - TELNET - FTP - HTTP - HTTPS with Openssl2 - SSH2 Secure Shell Login - Alarm messages via e-mail - IPv6 - 3 global IPv6 addresses configurable - Autoc
Additional Features and Options - external NTP timeserver - free configuration of NTP: thereby MD5 authentication and access control via address & mask restriction - extended menu guidance for configuration and monitoring via Telnet, SSH or serial terminal interface - optional up to 3 RJ45/10/100 Mbit Ethernet interfaces - extended HTTP statistic support with long-term graphic and access statistic to NTP - alarm messages can be displayed on external large display VP100/20/NET - USB memory stick slot for ext
Why to use a Network Timeserver A network timeserver should be used if accurate time is essential for undisturbed operation. It is possible to synchronize computers in a network using Public Domain Time servers over the Internet, but there are good reasons not to use them: - The possibility to send notification via e-mail or SNMP-Trap to an administrator in the event of any synchronisation failure. - The computers in the network do not have a reliable internet connection.
NTP Target The software package NTP was tested on different UNIX systems. Many UNIX systems have pre-installed a NTP client. Only some configurations have to be made (/etc/ntp.conf). NTP clients as freeware or shareware are also available for the most other operating systems like Windows XP/2000/NT/95/98/3x, OS2 or MAC. The following WEB site is recommended to get the latest version of NTP: "http://www.eecis.udel.edu/~ntp/". More information you can find on our web page at "http://www.meinberg.
The high precision orbit parameters of a satellite are called ephemeris parameters whereas a reduced precision subset of the ephemeris parameters is called a satellite’s almanac. While ephemeris parameters must be evaluated to compute the receiver’s position and clock offset, almanac parameters are used to check which satellites are in view from a given receiver position at a given time. Each satellite transmits its own set of ephemeris parameters and almanac parameters of all existing satellites.
Mounting the GPS Antenna The GPS satellites are not stationary but circle round the globe in a period of about 12 hours. They can only be received if no building is in the line-of-sight from the antenna to the satellite, so the antenna/converter unit must be installed in a location from which as much of the sky as possible can be seen. The best reception is given when the antenna has a free view of 8° angular elevation above the horizon.
Assembly with CN-UB/E 18
Booting the GPS receiver If both, the antenna and the power supply, have been connected the system is ready to operate. About 2 minutes after power-up the receiver’s oscillator has warmed up and operates with the required accuracy. If the receiver finds valid almanac and ephemeris data in its battery buffered memory and the receiver’s position has not changed significantly since its last operation the receiver can find out which satellites are in view now.
For the synchronization of the NTPD with the GPS it is necessary that the GPS receiver is synchronous with the GPS time. In this case the following message is monitored on the display: GPS: NORMAL OPERATION NTP: Offset PPS: -50us Mon, 28.08.2006 UTC 14:33:10 The second line shows the user that the NTPD is synchronized with the GPS with an offset of -50us. Because of the internal time of the NTP which is adjusted by a software PLL (phase locked loop) it takes a certain time to optimise this offset.
Configuration User Interface There are several ways to configure the LANTIME parameters: Command Line Interface (CLI) via TELNET Command Line Interface via SSH Command Line Interface via serial terminal in front panel (38400/8N1/VT100) HTTP Interface Secure HTTP Interface (HTTPS) Front panel LCD Interface SNMP Management To put LANTIME into operation for the first time an IP address is entered via the front panel keys and LC display (refer to: DHCP IPv4 or AUTOCONF IPv6).
The menus in Detail Root Menu The root menu is shown when the receiver has completed initialization after powerup. With the four arrow buttons and the buttons „OK“, „ESC“, „F1“ and „F2“ the navigation and setting of parameters can be managed. Main menu can be reached by pressing „ESC“ some times. The main menu reflect some of the main parameters of the time server. First line displays the status of the Reference Clock.
When pressing the „OK“ button from main menu the version of the LANTIME software, the NTP and the LINUX kernel version will be displayed. TYP:ELX800 GPS170 SN:030100000000 M3x V5.26 2.6.12 NTP: 4.2.0 The following main menus will be displayed when pressing the „UP“ and „DOWN“ arrow buttons: GPS: NORMAL OPERATION NTP: Offest PPS: 1ms -> Reference Time Time Service OK <- Setup Outputs Network System <- -> Network System -> Global Cfg.
Menü: Reference Time The Reference Clock menu and all its sub menus will manage all status information and parameters of the reference clock.
Setup GPS Receiver Parameters -> Setup GPS Receiver Parameters Init GPS Receiver OK -> <- Setup GPS Antenna Length Setup GPS Simulation Mode <- Set Antenna Cable Length This menu asks the user to enter the length of the antenna cable. The received time frame is delayed by approx. 5ns per meter antenna cable. The receiver is able to compensate this delay if the exact cable length is given. The default value is 20m. The maximum value that can be entered is 500 m (only with low loss cable).
Init GPS Receiver -> Setup GPS Receiver Parameters Init GPS Receiver OK ->GPS Cold Boot
Init GPS Position When the receiver is primarily installed at a new location far away from the last position saved in the receiver’s memory the satellites in view and their Doppler will differ so much from those expected due to the wrong position that GPS has to scan for satellites in Warm Boot mode. Making the new approximately known position available to the receiver can avoid Warm Boot and speed up installation. Set Initial Position LAT: 51.1234 LON:10.
Info GPS Setup GPS -> Info GPS OK Setup Outputs <->Status & Version
GPS Satellite Constallation The SV constellation menu gives an overview of the current satellites (SVs) in view. The display shows the number of satellites with an elevation of 5° or more (In view), the number of satellites that can be used for navigation (Good) and the selected set of satellites which are used to update the receiver position (Sel).
Serial Outputs ->Setup COM 0
the display shows the zone and offset if daylight saving is off whereas the right part shows name and offset if daylight saving is on. These parameters are used to convert UTC to local time, e.g. MEZ = UTC + 1h and MESZ = UTC + 2h for central Europe. The range of date daylight saving comes in effect can be entered using the next two topics of the setup menu.
Menu: Time Service The NTP configuration page is used to set up the additional NTP parameters needed for a more specific configuration of the NTP subsystem. Reference Time -> Time Service OK <- Network System -> external NTP
Menu: Restart NTP If the time of the reference clock has changed (e.g. while testing with different times) the system time has to bet set with the time of the reference clock and the NTP has to be restarted.
Programmable pulse (Option) At the male connector type VG64 there are optionally three programmable TTL outputs (Prog Pulse 1-3), which are arbitrarily programmable. SETUP POUT X This menu is used for configuration of the pulse outputs. There are three pulse outputs available (POUT 1-3).
Timer mode POUT1 TIMER1: output active:low ON: 10:50:00 OFF: 11:00:00 POUT1 TIMER2: output active:low ON: 13:00:00 OFF: 14:00:00 POUT1 TIMER1: output active:low ON: 23:45:00 OFF: 09:30:00 If Timer mode is selected, a window as shown above is displayed. The switching plan is assigned per day. Three turn-on and turn-off times are programmable for each output. If a switching time has to be configured, only the turn-on and turn-off time must be programmed.
Cyclic mode Cyclic mode is used for generating periodically repeated pulses. POUT1 CYCLIC: output active:low TIME: 00:00:02 LNG: 00.10 sec The value in field 'Time' determines the time between two consecutive pulses (2 sec in example above). This cycle time must be entered as hours, minutes and seconds. The pulse train is synchronized at 0:00 o'clock local time, so the first pulse of a day always occurs at midnight. A cycle time of 2 seconds for example, would cause pulses at 0:00:00, 0:00:02, 0:00:04 etc.
Menu: Synthesizer Frequency Output (Option) The Frequency Synthesizer is an optional output. Synthesizer Frequency Output Frequence: 100.0 Hz Phase: 090.0 This setup menu lets the user edit the frequency and phase to be generated by the on-board synthesizer. Frequencies from 1/8 Hz up to 10 MHz can be entered using four digits and a range. The range can be selected if the „UP“ or „DOWN“ key is pressed while the cursor is positioned on the frequency´s units string.
Menu: Network Reference Time Time Service OK -> Network System -> Global Cfg. Interfaces <- Services ->Hostname Interfaces Namesrv. Syslog Netw.LED Services <-> Ipv4 Parameter Ipv6 Parameter OK Global Cfg. Interfaces OK <- -> <- Link Mode Services <- >SSH:on < TELN:on FTP:on SNMP:off IPv6:on HTTP:on HTTPS:on NETB:off In this submenu the network configuration parameters related to the network interfaces can be changed.
Setup Global Configuration -> Global Cfg. Interfaces OK <- Services ->Hostname
Setup Network Interfaces Global Cfg. -> Interfaces Services <-> Ipv4 Parameter Ipv6 Parameter OK <- Link Mode Setup Network Ipv4 Parameter -> ETH0 ETH1 OK <- Def.Gateway >DHCP: disabled< ADDR: 192.168.10.2 NETMASK: 255.255.255.0 There is a separate configuration submenu for every physical network interface. If there is no DHCP client mode activated a static IP address for each interface can be entered. IPv4 addresses are built of 32 bits which are grouped in four octets, each containing 8 bits.
Menu: Setup Ipv6 Parameter Ipv4 Parameter -> Ipv6 Parameter OK Link Mode <- -> Link Local
Menu: Setup Services Global Cfg. Interfaces OK -> Services <- >SSH:on < TELN:on FTP:on SNMP:off IPv6:on HTTP:on HTTPS:on NETB:off The possible network protocols and access methods can be configured. After pressing the OK button you can enable/disable SSH, TELNET, SNMP, FTP, IPV6, HTTP, HTTPS and NETBIOS by using the UP/DOWN Keys and navigate through the list with the LEFT/RIGHT keys.
This menu lets the user enter the names of the local time zone with daylight saving disabled and enabled, together with the zones´ time offsets from UTC. The left part of the display shows the zone and offset if daylight saving is off whereas the right part shows name and offset if daylight saving is on. These parameters are used to convert UTC to local time, e.g. MEZ = UTC + 1h and MESZ = UTC + 2h for central Europe.
The LANTIME configuration interfaces The LANTIME offers three different options for configuration and status management: Web interface, Command Line Interface Setup and SNMP. In order to use the SNMP features of your LANTIME, you need special software like management systems or SNMP clients. In order to use the web interface, all you need is a web browser (LANTIME supports a broad range of browsers).
The WEB interface Connect to the web interface by entering the following address into the address field of your web browser: http://198.168.10.10 (You need to replace 198.168.10.10 with the IP address of your LANTIME). If you want to use an encrypted connection, replace the http:// with https:// in the above address. You may be prompted to accept the SSL certificate of your LANTIME the first time you are connecting to the system via HTTPS.
This page will be reloaded every 30 seconds in order to reflect the current status of the unit. Please bear this in mind when you try to login and enter your password. If you do not press ENTER or the Login button within 30 seconds, the user and password field is cleared and you have to start over again.
Configuration: Main Menu After entering the right password, the main menu page shows up. This page contains an overview of the most important configuration and status parameters for the system. The start page gives a short overview of the most important configuration parameters and the runtime statistics of the unit. In the upper left corner you can read which LANTIME model and which version of the LANTIME software you are using.
Configuration: Ethernet 48
In the network configuration all parameters related to the network interfaces can be changed. In the first section you can change the hostname and domain name. You can also specify two nameserver and two SYSLOG server. In the nameserver and syslog server fields you may enter an IPv4 or IPv6 address (the syslog servers can be specified as a hostname, too). All information written to the LANTIME SYSLOG (/var/log/messages) can be forwarded to one or two remote SYSLOG servers.
Network interface specific configuration The interface specific parameters can be found in the Interface section. If your LANTIME is equipped with only one network interface, you will find only one sub section (Interface 0). Otherwise you see a sub section for each installed Ethernet port. Here, the parameters for the network port can be changed. In the upper section of the page you can enter the IPv4 parameters, the lower part gives you access to the IPv6 parameters of the interface.
Examples: "::" is the address, which simply consists of zeros "::1" is the address, which only consists of zeros and a 1 as the last bit. This is the so-called host local address of IPv6 and is the equivalent to 127.0.0.1 in the IPv4 world "fe80::0211:22FF:FE33:4455" is a typical so-called link local address, because it uses the “fe80” prefix. In URLs the colon interferes with the port section, therefore IPv6IP-addresses are written in brackets in an URL.
Additional Network Configuration You can configure additional network parameter like special network routes or alias definitions. For this you will edit a script file which will be activated every time after the network configuration will run. Also the Samba Configuration from “/etc/samba/smb.
Configuration: Notification 53
Alarm events On this page you can set up different notification types for a number of events. This is an important feature because of the nature of a timeserver: running unobserved in the background. If an error or problem occurs, the timeserver is able to notify an administrator by using a number of different notification types.
Windows Popup Messages Most Microsoft Windows operating systems provide you with a local notification tool. You can send messages via the special Windows protocol in your local network. It is not necessary to enable the NETBIOS protocol of the LANTIME in order to use this notification. On the Windows client side it is necessary to activate the “Microsoft Client for Windows” in the network configuration. You can enter the Windows computer name of up to two Windows PCs in the appropriate fields.
User defined Alarm scripts You can define your own alarm script for every event by using the “Edit user defined notification script”. This script will be called automatically if one of the selected events occurs. This user alarm script will be stored on the Flash-Disk at “/mnt/flash/user_defined_notification”. This script will be called with index and the alarm message as text. The index value of the test message is 0.
Alarm messages You can change the alarm message text for every event by using the “Edit Messages“ button, the messages are stored in a file /mnt/flash/notification_messages on the flash disk of your timeserver.
Configuration: Security 58
Password On the “Security“ page you can manage all security relevant parameters for your timeserver. In the first section “Login” the administration password can be changed, which is used for SSH, TELNET, FTP, HTTP and HTTPS access. The password is stored encrypted on the internal flash disk and can only be reset to the default value “timeserver” by a “factory reset”, changing all settings back to the factory defaults. Please refer to the LCD configuration section in this manual.
SSH Secure Shell Login The SSH provides you with a secure shell access to your timeserver. The connection is encrypted, so no readable passwords are transmitted over your network. The actual LANTIME version supports SSH1 and SSH2 over IPv4 and IPv6. In order to use this feature, you have to enable the SSHD subsystem and a security key has to be generated on the timeserver by using the “Generate SSH key” button. Afterwards, a SSH client can connect to the timeserver and opens a secure shell: ssh root @ 192.
Generate SSL Certificate for HTTPS HTTPS is the standard for encrypted transmission of data between web browser and web server. It relies on X.509 certificates and asymmetric crypto procedures. The timeserver uses these certificates to authenticate itself to the client (web browser). The first time a web browser connects to the HTTPS web server of your LANTIME, you are asked to accept the certificate of the web server.
NTP keys and certificates The fourth and fifth section of the “Security“ page allow you to create the needed crypto keys and certificates for secure NTP operation (please see NTP authentication below). The function “Generate new NTP public key“ is creating a new self-signed certificate for the timeserver, which is automatically marked as “trusted“. Important note: This certificate is depending on the hostname of your LANTIME, it is mandatory to re-create the certificate after changing the hostname.
Configuration: NTP The NTP configuration page is used to set up the additional NTP parameters needed for a more specific configuration of the NTP subsystem. The default configuration of the timeserver consists of a local clock, which represents the hardware clock of your LANTIME system and the GPS reference clock. The local clock is only chosen as the NTP time reference after the GPS clock lost its synchronisation.
available by using the ATOM driver of the NTP subsystem, which is directly interpreting the PPS (pulse per second) of the GPS reference clock. The default configuration looks like this: # *** lantime *** # NTP.CONF for GPS167 with UNI ERLANGEN server fudge 127.127.1.0 127.127.1.0 stratum 12 # local clock # local stratum server 127.127.8.0 mode 135 prefer fudge 127.127.8.0 time1 0.0042 server 127.127.22.0 fudge 127.127.22.0 flag3 1 enable stats statsdir /var/log/ statistics loopstats driftfile /etc/ntp.
The NTP Trusttime will specify the time how long the NTP will trust the reference time if this is not synchronized (free running). This time will be set in seconds or minutes or hours. The value 0 will be select the default value for the specific reference clock. The default values are: LANTIME/GPS : 96 h LANTIME/PZF : 0,5 h LANTIME/RDT: 0,5 h LANTIME/NDT: 96 h After each restart and after any change of configuration a new /etc/ntp.conf file is generated by the LANTIME software.
NTP Authentication NTP version 2 and version 3 support an authentication method using symmetric keys. If a packet is sent by the NTPD while using this authentication mode, every packet is provided with a 32 bit key ID and a cryptographic 64/128 bit checksum of the packet. This checksum is built with MD5 or DES, both algorithms offer a sufficient protection against manipulation of data.
The ntp.keys file mentioned above holds a list of all keys and their respective ID known by the server. This file should not be world-readable (only root should be able to look into this) and it may look like this: # ntp keys file (ntp.
NTP AUTOKEY NTP Version 4 supports symmetric keys and additionally provides the so-called AUTOKEY feature. The authentic of received time at the NTP clients is sufficiently ensured by the symmetric key technique. In order to achieve a higher security, e.g. against so-called replay attacks, it is important to change the used crypto keys from time to time. In networks with a lot of clients, this can lead to a logistic problem, because the server key has to be changed on every single client.
A LANTIME can be a trusted authority / trusted host combination and also a “nontrusted” host in such a secure group. To configure the LANTIME as a TA / trusted host, enable the AUTOKEY feature and initialise the group key via the HTTPS web interface (“Generate groupkey”) or CLI setup program. In order to create such a group key, a crypto password has to be used in order to encrypt / decrypt the certificate.
Example: This autokey group is formed by one Stratum-1-server (B), two Stratum-2-servers (D and E) and a number of clients (in the diagram there are 4 clients shown, c1 – c4). B is the trusted host, he holds the group key and a self-signed certificate marked as “trusted”. D and E are NTP servers, which are “non-trusted” hosts of the group, they hold the group key and a self-signed certificate which lacks the “trusted” mark. The clients also hold the group key and a self-signed certificate.
Configuration: Local 71
Administrative functions In the first section there are several functions which may be used by the administrator. The button “Reboot LANTIME” is restarting the system, the built-in reference clock is not affected by this, only the included computer system is rebooted, which may take up to 30 seconds. With “Manual configuration“ you are able to change the main configuration by editing the configuration file by hand.
Please be aware of the fact that the default configuration is not activated instantly. If you want to avoid setting up the IP address of your unit by locally configuring it on site with the buttons of the front panel (meaning physical presence of someone directly at the location of the LANTIME), you have to configure the network parameters of your LANTIME immediately after using the “reset to factory defaults” button.
Administrative Information The button “List all messages“ displays the SYSLOG of the LANTIME completely. In this log all subsystems create their entries, even the OS (upper case) kernel. The SYSLOG file /var/log/messages is only stored in the system’s ram disk, therefore it is lost after a power off or restart. If you configured an external SYSLOG server, all LANTIME syslog entries will be duplicated on this remote system and can be saved permanently this way. Mar 15 13:35:17 LanGpsV4 ntpd[12948]: ntpd 4.2.
Using the button ”List detailed GPS information“ gives you the possibility to check detailed GPS status information. The first parameter indicates the time and date of the last update of the shown parameters. Next you find the GPS receiver status and the NTP status, followed by the GPS position data. The position uses the Latitude / Longitude / Altitude format. Latitude and Longitude are shown in degrees, minutes and seconds, Altitude is shown in meters above sea level.
Software Update If you need to update the software of your LANTIME, you need a special file from Meinberg, which can be uploaded to the LANTIME by first choosing the file on your local computer with the “Browse” button and then press “Start firmware update”. The chosen file will be uploaded to the LANTIME, afterwards you are prompted to confirm the start of the update process. The scope of the update only depends on the chosen file.
Automatic configuration check All parameters of the LANTIME can be checked for plausibility and all configured servers (e.g. SYSLOG servers, nameservers) are tested for reachability. All red coloured values should be reviewed by the administrator. Because all configured hostnames / IP addresses of the servers are processed during the reachabilitytests, the whole check process may take a while.
Get Diagnostics Information The diagnostics information is a set of configuration parameters and files stored in a packed text file. With the help of these informations the technical support from Meinberg can reproduce the current state of your LANTIME. It takes some time to collect all information from the LANTIME. Do not press the button again while this process is running - some web browsers will cancel the job if you press the button twice. After that you can download the packed file “config.
Configuration: Statistics 79
Statistical Information In the first section a graphical diagram shows the running synchronisation process. NTP is storing this statistical information in so-called “loopstats” files, which are used here to draw the curves. The red line is describing the offset between the internal reference clock (GPS) and the system clock. The blue line shows the frequency errors of the system time (in PPM, parts per million).
Configuration: Manual This page gives you access to the documents stored on your LANTIME, especially the manuals and your own notes. The two lists include filename, language, file type, date and size of the documents/notes. The LANTIME documents can be downloaded from here in order to read / print them on your workstation.
If you want to add a note (you can maintain more than one note on your LANTIME), after choosing the button “add note” you have to enter a filename (without a directory path, all notes are stored in a fixed directory on the flash disk of your LANTIME) and the language of your note first. After you confirmed these parameters with “Add document”, you are able to edit the text of your new note.
The Command Line Interface The command line interface (CLI) can be used within a TELNET or SSH session. After login, just enter “setup” to start the CLI setup tool. The start page gives a short overview of the most important configuration parameters and the runtime statistics of the unit. In the upper left corner you can read which LANTIME type and version of the LANTIME software you are using. This LANTIME software version is a head version number describing the base system and important subsystem.
CLI Ethernet In the network configuration all parameters related to the network interfaces can be changed. In the first section you can change the hostname and domain name. You can also specify two nameservers and two SYSLOG servers. In the nameserver and SYSLOG server fields you may enter an IPv4 or IPv6 address (the SYSLOG servers can be specified as a hostname, too). All information which is written to the LANTIME SYSLOG (/var/log/messages) can be forwarded to one or two remote SYSLOG servers.
timeserver cannot be reached with IPv4. Please note that TELNET, FTP and NETBIOS cannot be used over IPv6 in this version. IPv4 and IPv6 can be used together on one LANTIME. To manage the interface specific parameters, you can enter the Ethernet Configuration Line page by using one of the ETHERNET buttons. If your LANTIME is equipped with only one network interface, you will find only one button (ETHERNET 0). Otherwise you see one button for each installed Ethernet port.
If the DHCP client has been activated, the automatically obtained parameters are shown in the appropriate fields (IPv4 address, netmask, gateway). You can specify up to three IPv6 addresses for your LANTIME timeserver. Additionally you can switch off the IPv6 AUTOCONF feature. IPv6 addresses are 128 bits in length and written as a chain of 16 bit numbers in hexadecimal notation, separated with colons. A sequence of zeros can be substituted with “::” once.
CLI Notification Alarm events On this page you can set up different notification types for a number of events. This is an important feature because of the nature of a timeserver: running in the background. If an error or problem occurs, the timeserver is able to notify an administrator by using a number of different notification types.
E-mail messages You can specify the e-mail address which is used as the senders address of the notification e-mail (From: address), the e-mail address of the receiver (To: address) and a SMTP smarthost, that is a mail server who is forwarding your mail to the receiver. If your LANTIME system is connected to the internet, it can deliver those emails itself. Additional e-mail recipients can be configured with the button “CC recipients”.
SNMP-TRAP messages Up to two SNMP trap receiver hosts can be configured in this subsection, you may use IPv4 or IPv6 addresses or specify a hostname. Additionally you have to enter a valid SNMP community string for your trap receiving community. These are mostly independent from the SNMP community strings used for status monitoring and configuration (see SNMP configuration on the “Security” page).
NTP Client Monitoring You can monitor a group of NTP clients and supervise the time offset, the NTP stratum value and if the client is reachable or not. With the button „edit client list“ you can edit the list of clients to monitor.
CLI Security Password On the “Security“ page you can manage all security relevant parameters for your timeserver. In the first section “Login” the administration password can be changed, which is used for SSH, TELNET, FTP, HTTP and HTTPS access. The password is stored encrypted on the internal flash disk and can only be reset to the default value “timeserver” by a “factory reset”, changing all settings back to the factory defaults. Please refer to the LCD configuration section in this manual.
If you enabled SSH, your LANTIME automatically is able to use secure file transfer with SCP or SFTP protocol. The usage of FTP as a file transfer protocol is as insecure as using TELNET for shell access. Generate SSL Certificate for HTTPS HTTPS is the standard for encrypted transmission of data between web browser and web server. It relies on X.509 certificates and asymmetric crypto procedures. The timeserver uses these certificates to authenticate itself to the client (web browser).
CLI NTP Parameter The NTP configuration page is used to set up the additional NTP parameters needed for a more specific configuration of the NTP subsystem. The default configuration of the timeserver consists of a local clock, which represents the hardware clock of your LANTIME system and the GPS reference clock. The local clock is only chosen as the NTP time reference after the GPS clock lost its synchronisation.
CLI NTP Authentication Please see the corresponding chapter in the web interface description. CLI NTP Autokey Please see the corresponding chapter in the web interface description.
CLI Local Administrative functions In the first section there are several functions which may be used by the administrator. The button “Reboot LANTIME” is restarting the system, the built-in reference clock is not affected by this, only the included computer system is rebooted, which may take up to 30 seconds. With “Manual configuration“ you are able to change the main configuration by editing the configuration file by hand.
The function “Reset to factory defaults“ is setting all configuration parameters back to default values. The regular file /mnt/flash/global_configuration will be replaced with the file /mnt/flash/factory.conf, but first a copy of the configuration is saved under /mnt/flash/global_configuration.old for backup reasons. The default password “timeserver” is replacing the actual password, too. After using this function, all certificates should be recreated because of the change of the unit’s hostname.
Mar 15 13:35:17 LanGpsV4 ntpd[12948]: frequency initialized 45.212 PPM from /etc/ntp.drift Mar 15 13:38:36 LanGpsV4 lantime[417]: NTP sync to GPS Mar 15 13:38:36 LanGpsV4 lantime[417]: NTP restart Mar 15 13:45:36 LanGpsV4 proftpd[14061]: connect from 172.16.3.2 (172.16.3.2) Mar 15 14:01:11 LanGpsV4 login[15711]: invalid password for `root' on `ttyp1' from `172.16.3.45' Mar 15 14:01:17 LanGpsV4 login[15711]: root login on `ttyp1' from `172.16.3.
The next section “Satellite Info“ shows information about all the satellites, which are in view momentarily. The satellite ID, elevation, Azimuth and distance to the receiver reveal the position of the satellite in the sky. The Doppler shows whether the satellite is ascending (positive values) or descending (negative value). Software Update If you need to update the software of your LANTIME, you need a special file update.
SNMP Support The Simple Network Management Protocol (SNMP) has been created to achieve a standard for the management of different networks and the components of networks. SNMP is operating on the application layer and uses different transport protocols (like TCP/IP and UDP), so it is network hardware independent. The SNMP design consists of two types of parties, the agent and the manager. SNMP is a client-server architecture, where the agent represents the server and the manager represents the client.
...mbgLtNtp.mbgLtNtpCurrentState.0 = 1 : no good refclock (->local) ...mbgLtNtp.mbgLtNtpCurrentStateVal.0 = 1 ...mbgLtNtp.mbgLtNtpStratum.0 = 12 ...mbgLtNtp.mbgLtNtpActiveRefclockId.0 = 1 ...mbgLtNtp.mbgLtNtpActiveRefclockName.0 = LOCAL(0) ...mbgLtNtp.mbgLtNtpActiveRefclockOffset.0 = 0.000 ms ...mbgLtNtp.mbgLtNtpActiveRefclockOffsetVal.0 = 0 ...mbgLtNtp.mbgLtNtpNumberOfRefclocks.0 = 3 ...mbgLtNtp.mbgLtNtpAuthKeyId.0 = 0 ...mbgLtNtp.mbgLtNtpVersion.0 = 4.2.0@1.1161-r Fri Mar 5 15:58:56 CET 2004 (3) ...
Configuration over SNMP The LANTIME timeserver can be configured via several user interfaces. Besides the possibility to setup its parameters with the web interface (HTTP and/or HTTPS) and the direct shell access via Telnet or SSH, a SNMP based configuration interface is available.
Examples for the usage of the SNMP configuration features The following examples are using the software net-snmp, a SNMP open source project. You will find detailed information at www.net-snmp.org! To browse the configuration branch of the timeserver-MIB, you could use the following command on a UNIX system with net-snmp SNMP tools installed: root@testhost:/# snmpwalk -v2c -c public timeserver.meinberg.de mbgLtCfg MBG-SNMP-LANTIME-CFG-MIB::mbgLtCfghostname.
The available SNMP variables are described in detail in the “SNMP configuration reference“ part of this manual. Additionally, it is recommended to also read the mentioned MIB files.
Further configuration possibilities Because the timeserver uses a standard version of the net-snmp SNMP daemon (with extended features covering the timeserver-specific functions), all configuration parameters of the SNMPD can be used. The configuration file of the SNMP daemon is located at /usr/local/share/snmp after boot time, the filename is snmpd.conf. During the boot sequence, this file is created dynamically by using a template file and appending the SNMP parameters stored in the timeserver setup.
GenerateHTTPSKey(5) A new HTTPS key will be generated. ResetFactoryDefaults(6) The configuration of the timeserver is reset to factory defaults, afterwards an automatic ReloadConfig is executed in order to use these default settings. GenerateNewNTPAutokeyCert(7) A new key is generated, it can be used with the NTP AUTOKEY feature. SendTestNotification(8) A test message is sent by using all notification methods the timeserver has a configuration for (e.g. mail, winpopup, SYSLOG etc.).
Configuration of the timeserver with SNMP: Reference The MIB of the timeserver includes the following parts: SNMP Object enterprises.5597 mbgSNMP.3 mbgLANTIME.1 mbgLANTIME.2 Name mbgSNMP MbgLANTIME mbgLtNtp mbgLtRefclock mbgLANTIME.3 mbgLANTIME.4 mbgLANTIME.
SNMP branch mbgLtCfgEMail mbgLtCfgSNMP mbgLtCfgWinpopup mbgLtCfgWalldisplay Variable mbgLtCfgNtpServer3KEY Data type integer Description Link to the key which should be used for the third NTP-server mbgLtCfgStratumLocalClock integer(0..
SNMP branch mbgLtCfgNotify Variable mbgLtCfgNotifyNTPNotSync Data type Description string(combination ) Exactly one, none or a combination of the following notification types: email=sending an email wmail=sending a winpopup-message snmp=sending a SNMP-trap, disp=showing on wall mount display, syslog=sending a syslog-entry mbgLtCfgNotifyNTPStopped mbgLtCfgNotifyServerBoot for the event „NTP not synchronized“ string (combination) (see mbgLtCfgNotifyNTPNotSync) for the event „NTP Daemon stopped“ string (c
SNMP Traps If configured, the LANTIME is sending SNMP traps, which can be received by up to 2 SNMP management systems. These traps can be received by using the NETSNMP suite tool “snmptrapd”, you can start it on a UNIX system with “snmptrapd – p” (-p is for output to stdout, -s would use the syslog for output). The corresponding MIB files can be found on the LANTIME at /usr/local/share/snmp/mibs/ , all Meinberg specific MIB files are named “MBG-SNMP….” .
SNMP Trap Reference All traps can be found under the mbgLtTraps section in the Meinberg MIB. A special trap exists for every notification event the timeserver knows. Please note that the traps are only sent if you configured the notification type “SNMP trap” for the event, otherwise no trap is generated.
Attachment: Technical Information Skilled/Service-Personnel only: Replacing the Lithium Battery The life time of the lithium battery on the board is at least 10 years. If the need arises to replace the battery, the following should be noted: ATTENTION! There is a Danger of explosion if the lithium battery is replaced incorrectly. Only identical batteries or batteries recommended by the manufacturer must be used for replacement.
Safety instructions for building-in equipment This building-in equipment has been designed and tested in accordance with the requirements of Standard IEC60950-1 "Safety of Information Technology Equipment, including Electrical Business Equipment". During installation of the building-in equipment in an end application (i.e. rack) additional requirements in accordance with Standard IEC60950-1 have to be taken into account.
Rear Panel Connectors Name Type Signal Cable 2x Network RJ-45 Ethernet shielded data line PPS 10 MHz, Time Sync Error BNC BNC DFK TTL TTL screw terminal shielded coaxial line shielded coaxial line COM0,COM1 9pol. DSUB RS232 shielded data line Antenna BNC 10 MHz / 35.4 MHz shielded coaxial line Power supply power cord receptable option 2x Network RJ-45 Ethernet shielded data line Time Code modulated DCLS BNC BNC 3Vpp into 50 Ohm 2.
RS232 TERMINAL To connect a serial terminal use 9 pin SUBD RS232 connector in the front panel. Via the serial terminal connection it possible to configure parameters with the command line interface. You have to use a NULL-MODEM cable connecting to your PC or Laptop computer. You can use e.g. the standard Hyperterminal program shipped with your Windows operating system. Configure your terminal program with 38400 Baud, 8 Databits, no parity and 1 Stopbit. The terminal emulation have to set to VT100.
Time Sync Error Relay On the back panel of the device you can find a DFK connector labeled „Time Sync Error“. This relay output is connected to the TTL TIME_SYNC out of the reference clock (GPS, PZF, TCR, ...). By default the relay will switch to mode „ON“ if the internal reference clock has not been synchronized by its sink (GPS, DCF77 or IRIG). This is the case if the reception of the antenna signal is bad or the device has been switched off.
Technical Specifications GPS receiver RECEIVER: 6 channel C/A code receiver with external antenna/converter unit ANTENNA: Antenna/converter unit with remote power supply refer to chapter "Technical Specifications GPS Antenna" ANTENNA INPUT: LC DISPLAY: TIME TO SYNCHRONIZATION: PULSE OUTPUTS: ACCURACY OF PULSES: Antenna circuit dc-insulated; dielectric strength: 1000 V Length of cable: refer to chapter "Mounting the Antenna" 1HE: 2 x 40 character, menu selectable by push buttons and light BGT: 4 x 16 Ze
1 Hz 10 H z 100 Hz 1 kH z phase noise -9 117 -11 +/- 13 sec +/- 2 * 10 -7 (0...60°C ) 5V / 160mA 5V / 380mA GPS161 G PS167 (SV) G PS170 (SV) GPS16xPCI (5V only) GPS16xPC (5V only) +/- 32 sec 5V / 20mA N/A GPS161 GPS163 GPS164 G PS167 (SV) G PS170 (SV) GPS16xPCI GPS16xPC +/- 1,8 m sec +/- 1 * 10 +/- 1 * 10 - 6 (-20...70°C) +/- 8,6 msec -11 -75 dBc/Hz -110 dBc/Hz -130 dBc/Hz -140 dBc/Hz -12 GPS161 G PS167 (SV) G PS170 (SV) 5V / 300mA 5V / 700mA +/- 5 * 10 -8 (-20...
Technical Specifications GPS Antenna ANTENNA: Dielectric patch antenna, 25 x 25 mm Receive frequency: 1575.42 MHz Bandwidth: 9 MHz CONVERTER: Local oscillator to converter frequency: 10 MHz First IF frequency: 35.4 MHz POWER REQUIREMENTS: 12 V ... 18 V, @ 100 mA (provided via antenna cable) CONNECTOR: Coax type N, female AMBIENT TEMPERATURE: -40 ...
Signal Description GPS170 Name Pin Function GND VCC in (+5 V) VCC in (+12 V) 32a+c 1a+c 2a+c Ground +5 V supply +12 V supply P_SEC out 6c P_MIN out 8c Pulse when second changes, TTL level, active high, length 200 msec Pulse when minute changes, TTL level, active high, length 200 msec DCF_MARK out 17c DCF77 compatible second marks, TTL level, active high, length 100/200 msec 100 kHz out 1 MHz out 10 MHz out 10a 11a 12a 100 kHz frequency output, TTL-level 1 MHz frequency output, TTL- level 10
Rear Connector Pin Assignments GPS170 a c 1 VCC in (+5V) VCC in (+5V) 2 VCC in (+12V) VCC in (+12V) 3 VDD in (TCXO/OCXO) VDD in (TCXO/OCXO) 4 (reserved, FreqAdjust out) 5 6 P_SEC out 7 8 (reserved, 10 MHz in) 9 P_MIN out /RESET in/out 10 100 kHz out ProgPulse0 out 11 1 MHz out ProgPulse1 out 12 10 MHz out ProgPulse2 out 13 SCL 14 SCL_EN 15 COM2 RxD in SDA 16 COM2 TxD out (reserved, P3.
Technical Specifications LAN CPU PROCESSOR: GeodeTM LX800 with 500 MHz MAIN MEMORY: 256 MB CACHE-MEMORY: 16 KB 2nd Level Cache FLASHDISK: NETWORK CONNECTOR: SERIAL INTERFACE: PARALLEL INTERFACE : 64 MB (128 MB) 10/100 MBIT with RJ45-Jack DAVICOM DM9102AEthernet NIC Controller Four serial RS232-Ports 16550 compatible to FIFO - RS232 9-pol.
Rear Connector Pin Assignments LAN CPU c b a 1 VCC in (+5V) VCC in (+5V) 2 VCC in (+5V) VCC in (+5V) VCC in (+5V) VCC in (+5V) 3 GND GND GND 4 PPS in /AFD out /STB out 5 /ERR in /SLIN out /INIT out 6 D5 in/out D6 in/out D7 in/out 7 D2 in/out D3 in/out D4 in/out 8 /ACK in D0 in/out D1 in/out 9 /SLCT in PE in /BUSY in 10 GND GND GND 11 GND GND GND 12 DIAG_S in/out /CS1 out /CS3 out 13 A0 out A1 out A2 out 14 RDY in /AK out INTRQ in 15 DRQ in /IOW out
Technical Specifications Power Supply INPUT: 85 ... 264 V AC, 47 ... 63 Hz, 1 A/230 V, 2 A/115 V FUSE: Electronic CURRENT LIMITING: 105 – 150 % Iout nom OUTPUTS: Vout1: Vout2: Vout3: 5.05 V / 5 A +12 V / 2.5 A -12 V / 0.5 A TOTAL LOAD: Max. 61 Watt CONNECTORS: Screw terminal HOUSING: Metal housing : 159 mm x 97 mm x 38 mm AMBIENT TEMPERATURE: -10 °C ... +60 °C HUMIDITY: 90 % max.
Timecode (option) Abstract The transmission of coded timing signals began to take on widespread importance in the early 1950´s. Especially the US missile and space programs were the forces behind the development of these time codes, which were used for the correlation of data. The definition of time code formats was completely arbitrary and left to the individual ideas of each design engineer.
IRIG Standard Format 125
AFNOR Standard Format 126
Assignment of CF Segment in IEEE1344 Code Bit No. Designation Description 49 Position Identifier P5 50 Year BCD encoded 1 51 Year BCD encoded 2 52 Year BCD encoded 4 53 Year BCD encoded 8 54 empty, always zero 55 Year BCD encoded 10 56 Year BCD encoded 20 57 Year BCD encoded 40 58 Year BCD encoded 80 59 Position Identifier P6 60 LSP - Leap Second Pending set up to 59s before LS insertion 61 LS - Leap Second 0 = add leap second, 1 = delete leap second 1.
Generated Time Codes Besides the amplitude modulated sine wave signal, the board also provides unmodulated DC-Level Shift TTL output in parallel. Thus six time codes are available.
Outputs The module GPS-TC provides modulated and unmodulated (DC-Level Shift) outputs. The format of the timecodes is illustrated in the diagramms "IRIG-" and "AFNOR standard-format". AM - Sine Wave Output The amplitude-modulated carrier is available at the VG-connector pin 14a. The carrier frequency depends on the code and has a value of 1 kHz (IRIG-B). The signal amplitude is 3 Vpp (MARK) and 1 Vpp (SPACE) into 50 Ω. The encoding is made by the number of MARK-amplitudes during ten carrier waves.
Time Strings Format of the Meinberg Standard Time String The Meinberg Standard Time String is a sequence of 32 ASCII characters starting with the STX (start-of-text) character and ending with the ETX (end-of-text) character. The format is: D:dd.mm.yy;T:w;U:hh.mm.ss;uvxy The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string.
Format of the GPS Capture String The Meinberg GPS Capture String is a sequence of 31 ASCII characters terminated by a CR/LF (Carriage Return/Line Feed) combination. The format is: CHx_tt.mm.jj_hh:mm:ss.fffffff The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string. The groups of characters as defined below: x _ 0 or 1 corresponding on the number of the capture input ASCII space 20h dd.mm.
Format of the SAT-Time String The SAT-Time String is a sequence of 29 ASCII characters starting with the STX (start-of-text) character and ending with the ETX (end-of-text) character. The format is: dd.mm.yy/w/hh:mm:ssxxxxuv The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string. The groups of characters as defined below: Start-Of-Text (ASCII code 02h) sending with one bit occuracy at change of second dd.mm.
Format of the Uni Erlangen String (NTP) The time string Uni Erlangen (NTP) of a GPS-clock is a sequence of 66 ASCII characters starting with the STX (start-of-text) character and ending with the ETX (end-of-text) character. The format is: tt.mm.jj; w; hh:mm:ss; voo:oo; acdfg i;bbb.bbbbn lll.lllle hhhhm The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string.
i leap second insertion ‘L’ leap second is actually inserted (active only in 60th sec.) ‘‘ (space, 20h) no leap second is inserted bbb.bbbb latitude of receiver position in degrees leading signs are replaced by a space character (20h) n latitude, the following characters are possible: ‘N’ north of equator ‘S’ south d. equator lll.
Format of the NMEA 0183 String (RMC) The NMEA String is a sequence of 65 ASCII characters starting with the ‘$’ character and ending with the characters CR (carriage return) and LF (line-feed). The format is: $GPRMC,hhmmss.ss,A,bbbb.bb,n,lllll.ll,e,0.0,0.0,ddmmyy,0.0,a*hh The letters printed in italics are replaced by ASCII numbers or letters whereas the other characters are part of the time string. The groups of characters as defined below: $ hhmmss.
Format of the ABB SPA Time String The ABB SPA Time String is a sequence of 32 ASCII characters starting with the characters ">900WD" and ending with the (Carriage Return) character. The format is: >900WD:yy-mm-tt_hh.mm;ss.fff:cc The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string. The groups of characters as defined below: yy-mm-tt _ the current date: yy year of the century mm month dd day of month (00..99) (01..12) (01..
Format of the COMPUTIME Time String The COMPUTIME Time String is a sequence of 24 ASCII characters starting with the characters “T" and ending with the (Line-Feed, ASCII-Code 0Ah) character. The format is: T:jj:mm:tt:ww:hh:mm:ss The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string.
Format of the RACAL standard Time String The RACAL standard Time String is a sequence of 16 ASCII characters terminated by a X (58h) character and ending with the CR (Carriage Return, ASCII Code 0Dh) character. The format is: yymmddhhmmss The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string.
Format of the SYSPLEX-1 Time String The SYSPLEX1 time string is a sequence of 16 ASCII characters starting with the SOH (Start of Header) ASCII controll character character and ending with the LF (line feed, ASCII Code 0Ah) character. The format is: ddd:hh:mm:ssq The letters printed in italics are replaced by ASCII numbers whereas the other characters are part of the time string.
Konformitätserklärung Declaration of Conformity Hersteller Meinberg Funkuhren GmbH & Co. KG Lange Wand 9 D-31812 Bad Pyrmont Manufacturer erklärt in alleiniger Verantwortung, dass das Produkt, declares under its sole responsibility, that the product Produktbezeichnung NTP Timeserver Product Name Lantime M300/GPS Modell / Typ Model Designation auf das sich diese Erklärung bezieht, mit den folgenden Normen übereinstimmt.
Manual VP100/NET Display configuration send2display Version 0.1 usage: send2display -h hostname -s serialnumber [options] Valid options are: -h, --host H -s, --serialnumber S -c, --clear M -b, --beep -a, --clearall -m, --message M -e, --executions E -q, --quiet -v, --verbose -?, --help Uses H as the hostname of the display unit Uses S as the serialnumber of the display (e.g.
If you want the message (any type) to appear periodically, you can set the time interval with: -D, --periodday D Display message every D days -H, --periodhour H Display message every H hours -M, --periodminute M Display message every M minutes (You can combine these options. Default is: message is displayed only once) Possible error codes: 1=parameter error, 2=no ACK from display, 3=network error Examples: send2display -h 172.16.3.
Global Configuration File This file contains all global parameters of the LANTIME. You can find this file on the write protected flash disk at /mnt/flash/global_configuration: #----------------------# Configuration File # #----------------------# Configuration File Section Configuration File Version Number Configuration File Last Change # Network Parameter Section Hostname Domainname IPv4 GATEWAY ..... IPv6 GATEWAY .....
SNMP Write Community String SNMP Contact String SNMP Location String # Windows Messages Section WMail Address 1 WMail Address 2 [ASCII,50]: [ASCII,50]:Meinberg [ASCII,50]:Germany [ASCII,50]: [ASCII,50]: # VP100 Display Section VP100 Display Address 1 VP100 Display Sernum 1 VP100 Display Address 2 VP100 Display Sernum 2 [ASCII,50]: [ASCII,50]: [ASCII,50]: [ASCII,50]: # Notification Section Notification on NTP_not_sync [CASE]: Notification on NTP_stopped [CASE]: Notification on Server_boot [CASE]: Notific
Third party software The LANTIME network timeserver is running a number of software products created and/or maintained by open source projects. A lot of people contributed to this and we explicitly want to thank everyone involved for her/his great work. The used open source software comes with its own license which we want to mention below.
Network Time Protocol Version 4 (NTP) The NTP project, lead by David L. Mills, can be reached in the internet at www.ntp.org. There you will find a wealthy collection of documentation and information covering all aspects of the application of NTP for time synchronization purposes. The distribution and usage of the NTP software is allowed, as long as the following notice is included in our documentation: *********************************************************************** * * * Copyright (c) David L.
GNU General Public License (GPL) GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 675 Mass Ave, Cambridge, MA 02139, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The licenses for most software are designed to take away your freedom to share and change it.
is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does. 1.
The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable.
countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. 9. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number.
Reference [Mills88] Mills, D. L., "Network Time Protocol (Version 1) - specification and implementation", DARPA Networking Group Report RFC-1059, University of Delaware, July 1988 [Mills89] Mills, D. L., "Network Time Protocol (Version 2) - specification and implementation", DARPA Networking Group Report RFC-1119, University of Delaware, September 1989 [Mills90] Mills, D. L.
