System Time
There are several reasons why your Oracle Communications Session Border Controller needs to keep an accurate reference to the system time. These include, but are not limited to, the need for accurate billing, logging, and the need to stay synchronized with other network equipment.
Setting Time
To manually set the system-time on your Oracle Communications Session Border Controller:
Setting Timezone
The timezone on the Acme Packet ESD must be set manually via the ACLI using one of two methods:
- using the timezone-set command at the root prompt. This commands starts a timezone wizard that allows you to answer prompts specifically related to timezone settings. You can set your timezone location and the wizard automatically sets the daylight savings time for the location you select.
- at the path system->timezone. This parameter allows you to create a timezone name and apply specific instructions for daylight savings time (DST) and specify the number of minutes from Coordinated Universal Time (UTC). If you initiated the timezone-set wizard previous to accessing this parameter, the settings for system->timezone are already populated. You can change them if required.
It is recommended you set the timezone after first boot of the system.
About UTC Timezones
Coordinated Universal Time (UTC) is used as the official world reference for time. Coordinated Universal Time replaced the use of Greenwich Mean Time (GMT) in 1972. Sometimes time zones are represented similar to UTC - 5h or GMT - 5h. In this example, the (-5h) refers to that time zone being five hours behind UTC or GMT and so forth for the other time zones. UTC +5h or GMT +5h would refer to that time zone being five hours ahead of UTC of GMT and so forth for the other time zones.
The usage of UTC and GMT is based upon a twenty four hour clock, similar to military time, and is based upon the 0° longitude meridian, referred to as the Greenwich meridian in Greenwich, England.
UTC is based on cesium-beam atomic clocks, with leap seconds added to match earth-motion time, where as Greenwich Mean Time is based upon the Earth's rotation and celestial measurements. UTC is also known as Zulu Time or Z time.
In areas of the United States that observe Daylight Saving Time, local residents move their clocks ahead one hour when Daylight Saving Time begins. As a result, their UTC or GMT offset would change from UTC -5h or GMT - 5h to UTC -4h or GMT - 4h. In places not observing Daylight Saving Time the local UTC or GMT offset will remain the same year round. Arizona, Puerto Rico, Hawaii, U.S. Virgin Islands and American Samoa do not observe Daylight Saving Time.
In the United States Daylight Saving Time begins at 2:00 a.m. local time on the second Sunday in March. On the first Sunday in November areas on Daylight Saving Time return to Standard Time at 2:00 a.m. The names in each time zone change along with Daylight Saving Time. Eastern Standard Time (EST) becomes Eastern Daylight Time (EDT), and so forth. A new federal law took effect in March 2007 which extends Daylight Saving Time by four weeks.
The United States uses nine standard time zones. From east to west they are Atlantic Standard Time (AST), Eastern Standard Time (EST), Central Standard Time (CST), Mountain Standard Time (MST), Pacific Standard Time (PST), Alaskan Standard Time (AKST), Hawaii-Aleutian Standard Time (HST), Samoa standard time (UTC-11) and Chamorro Standard Time (UTC+10).
The following tables identify the standard time zone boundaries and the offsets.
| Coordinated Universal Time (UTC) | Greenwich Mean Time (GMT) |
|---|---|
| UTC/GMT +0 | UTC/GMT +0 |
The following table identifies the United States GMT/UTC offsets.
| Time Zone in United States | Examples of Places in the United States in These Time Zones | UTC Offset Standard Time | UTC Offset Daylight Saving Time |
|---|---|---|---|
| Atlantic | Puerto Rico, US Virgin Islands | UTC - 4h | N/A |
| Eastern | Connecticut, Delaware, Florida, Georgia, part of Indiana, part of Kentucky, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, part of Tennessee, Vermont Virginia, and West Virginia | UTC - 5h | UTC - 4h |
| Central | Alabama, Arkansas, Florida, Illinois, part of Indiana, Iowa, part of Kansas, part of Kentucky, Louisiana, part of Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Dakota, Oklahoma, part of South Dakota, part of Tennessee, most of Texas, and Wisconsin | UTC - 6h | UTC - 5h |
| Mountain | Arizona*, Colorado, part of Idaho, part of Kansas, Montana, part of Nebraska, New Mexico, part of North Dakota, part of Oregon, part of South Dakota, part of Texas, Utah, and Wyoming | UTC - 7h | UTC - 6h
*n/a for Arizona |
| Pacific | California, part of Idaho, Nevada, most of Oregon, Washington | UTC - 8h | UTC - 7h |
| Alaska | Alaska and a portion of the Aleutian Islands that is east of 169 degrees 30 minutes west longitude observes the Alaska Time Zone | UTC - 9h | UTC - 8h |
| Hawaii-Aleutian | Hawaii and a portion of the Aleutian Islands that is west of 169 degrees 30 minutes west longitude observes the Hawaii-Aleutian Standard Time Zone. ALthough Hawaii does not observe daylight savings time, the Aleutian Islands do observe daylight saving time. | UTC - 10h | UTC - 9h
Hawaii does not observe daylight saving time |
Using the Timezone-Set Wizard
You can configure the timezone on the Acme Packet ESD by running a timezone-set wizard from the root location via the ACLI. Use the following procedure to configure the Acme Packet ESD timezone. If you need to exit the timezone-set command before completing it, use the key sequence Ctrl-D.
Note:
The procedure described below may display different prompts depending on whether your system is running on VXWorks or LINUX.To configure the timezone:
Configuring Timezone using POSIX Format
If you want to configure the timezone using POSIX format, you can select the option none - I want to specify the time zone using the Posix TZ format in Step 2 of the timezone-set wizard. If you need to exit the timezone-set command before completing it, use the key sequence Ctrl-D.
To set the timezone using POSIX format:
Displaying the System Timezone
You can display the timezone configured for your Oracle Communications Session Border Controller using the ACLI show timezone command from the root prompt.
ORACLE# show timezone
America/New_York
ORACLE#To show more specific information about timezone settings, such as daylight savings time, navigate to the timezone parameter at the path , and initiate the show command. The following example shows the results from the show command.
ORACLE(timezone)# show
timezone
name TimezoneA
minutes-from-utc 240
dst-start-month 1
dst-start-day 1
dst-start-weekday sunday
dst-start-hour 1
dst-start-rule disabled
dst-end-month 1
dst-end-day 1
dst-end-weekday sunday
dst-end-hour 1
dst-end-rule disabledNTP Synchronization
This section provides information about how to set and monitor NTP on your Oracle Communications Session Border Controller.
When an NTP server is unreachable or when NTP service goes down, the Oracle Communications Session Border Controller generates traps for those conditions. Likewise, the Oracle Communications Session Border Controller clears those traps when the conditions have been rectified. The Oracle Communications Session Border Controller considers a configured NTP server to be unreachable when its reach number (whether or not the NTP server could be reached at the last polling interval; successful completion augments the number) is 0. You can see this value for a server when you use the ACLI show ntp server command.
- The traps for when a server is unreachable and then again reachable are: apSysMgmtNTPServerUnreachableTrap and apSysMgmtNTPServerUnreachableClearTrap
- The traps for when NTP service goes down and then again returns are: apSysMgmtNTPServiceDownTrap and apSysMgmtNTPServiceDownClearTrap
Setting NTP Synchronization
When the Oracle Communications Session Border Controller requires time-critical processing, you can set NTP for time synchronization. Setting NTP synchronizes both the hardware and the software clocks with the reference time from an NTP server that you specify. NTP is most useful for synchronizing multiple devices located on one network, or across many networks, to a reference time standard.
To guard against NTP server failure, NTP is restarted periodically to support the dynamic recovery of an NTP server.
Note that ntp-sync works only by way of the management interface and only on wancom0. Do not configure ntp-sync by way of the media interface or any other port.
To set NTP synchronization:
Authenticated NTP
The Oracle Communications Session Border Controller can authenticate NTP server requests using MD5. The configured MD5 keys are encrypted and obscured in the ACLI. You configure an authenticated NTP server with its IP address, authentication key, and the key ID. Corresponding key and key IDs are provided by the NTP server administrator.
To configure an authenticated NTP server:
Monitoring NTP from the ACLI
NTP server information that you can view with the show ntp server command tell you about the quality of the time being used in terms of offset and delays measurements. You can also see the maximum error bounds.
When you use this command, information for all configured servers is displayed. Data appears in columns that are defined in the table below:
| Display Column | Definition |
|---|---|
| server | Lists the NTP servers configured on the
Oracle Communications Session Border Controller by IP address. Entries are accompanied by characters:
Plus sign (+)—Symmetric active server Dash (-)—Symmetric passive server Equal sign (=)—Remote server being polled in client mode Caret (^)—Server is broadcasting to this address Tilde (~)—Remote peer is sending broadcast to * Asterisk (*)—The peer to which the server is synchronizing |
| st | Stratum level—Calculated from the number of computers in the NTP hierarchy to the time reference. The time reference has a fixed value of 0, and all subsequent computers in the hierarchy are n+1. |
| poll | Maximum interval between successive polling messages sent to the remote host, measured in seconds. |
| reach | Measurement of successful queries to this server; the value is an 8-bit shift register. A new server starts at 0, and its reach augments for every successful query by shifting one in from the right: 0, 1, 3, 7, 17, 37, 77, 177, 377. A value of 377 means that there have been eight successful queries. |
| delay | Amount of time a reply packet takes to return to the server (in milliseconds) in response. |
| offset | Time difference (in milliseconds) between the client’s clock and the server’s. |
| disp | Difference between two offset samples; error-bound estimate for measuring service quality. |
View Statistics
To view statistics for NTP servers:
- At the command line, type show ntp server and press Enter.
ORACLE# show ntp server
NTP Status FRI APR 11:09:50 UTC 2007
server st poll reach delay offset disp
----------------------- -- ---- ------ ------- -------- ---------
*64.46.24.66 3 64 377 0.00018 0.000329 0.00255
=61.26.45.88 3 64 377 0.00017 0.002122 0.00342You can the see the status of NTP on your system by using the show ntp status command. Depending on the status of NTP on your system, one of the following messages will appear:
- NTP not configured
- NTP Daemon synchronized to server at [the IP address of the specific server]
- NTP synchronization in process
- NTP down, all configured servers are unreachable
Automated Daylight Savings Time (DST) Updates
In addition to configuring DST at the command prompt, the Oracle Communications Session Border Controller provides a mechanism to create static or rules-based time updates to reflect your location’s seasonal Daylight Savings Time changes. This configuration offsets the Oracle Communications Session Border Controller ’s internal time, obtained via NTP or from ACLI configuration. When DST is configured as a configuration element, it is persistent across reboots.
When the DST start date/time is reached, 1 hour is added to the system clock. When the DST end date/time is reached, 1 hour is subtracted from the system clock.
Baseline Configuration
To complete automated DST configuration, you must give a name to the time zone that this system adheres to and the minutes from UTC (offset) from UTC, entered as +/-720.
Static DST Updates
You can configure the Oracle Communications Session Border Controller to enact and rescind DST offset on a predefined start and stop date. This is set with the following parameters:
dst start/end rule — This parameter is set to static when configuring static DST start and end times.
dst start/end month — The month when DST offset begins or ends, entered as 1-12.
dst start/end day — The day of the month when DST offset begins or ends, entered as 1-31.
dst start/end hour — The hour on the chosen day when DST offset starts or ends, entered as 0-23.
Rules-based DST Updates
You can configure the Oracle Communications Session Border Controller to enact and rescind DST offset based on rules that correspond to relative dates in a month. That is, start and stop dates can be the Nth (or last) day-name, in a calendar month, as opposed to a day-number of the month.
dst start/end rule — This parameter is set to ordinal number of the start/stop weekday when configuring rules-based DST start and end times. This parameter is entered as: first | second | third | fourth | last.
dst start/end month — The month when DST offset begins or ends, entered as 1-12.
dst start/end weekday — The named day when DST offset begins or ends, entered as: sunday | monday | tuesday | wednesday | thursday | friday | saturday.
dst start/end hour — The hour on the chosen day when DST offset starts or ends, entered as 0-23.
dst start/end day is not configured when entering rules based DST updates.
DST Update Examples
The current DST rule for North America is that daylight savings starts on the second Sunday in March at 2:00am and ends on the first Sunday in November at 2:00am. Thus the settings for the Eastern Time Zone would be as follows:
name = EST
minutes-from-utc = 300
dst-start-month = 3
dst-start-day = 1
dst-start-weekday = sunday
dst-start-hour = 2
dst-start-rule = second
dst-end-month = 11
dst-end-day = 1
dst-end-weekday = sunday
dst-end-hour = 2
dst-end-rule = firstNote:
The dst-start-day and dst-end-day values are ignored.The European Union directive states that DST starts on the last Sunday in March at 1:00am UTC and ends on the last Sunday in October at 1:00am UTC. Therefore the timezone settings for the UK would be:
name = GMT
minutes-from-utc = 0
dst-start-month = 3
dst-start-day = 1
dst-start-weekday = sunday
dst-start-hour = 1
dst-start-rule = last
dst-end-month = 10
dst-end-day = 1
dst-end-weekday = sunday
dst-end-hour = 2
dst-end-rule = lastNote the dst-end-hour is 2 because this is the local time and 2am BST is 1am UTC.