Before connecting the IMG 2020 to a network it must be synchronized to a T1/E1 loop timing source such as a T1 or E1 span. The IMG 2020 can be configured to accept six separate clock sources connected to various inputs on the rear of the unit. The Timing Synchronization Priority object defines the priority that the IMG 2020 will use to get a clock source from a T1/E1 span. Once the timing sources are connected, the Timing Synchronization Priority List is used to determine which source gets highest priority, 2nd highest priority, and so forth to lowest priority. To create the Timing Synchronization Priority List, right click on the Name object and select New Timing Synchronization Priority List. Below is an explanation of each of the timing references and how they are used. The priority can be changed at any time as described below.
Web GUI Page
Dialogic >IMG 2020> New Timing Synchronization Priority List
Maximum Objects
One Synchronization Priority list can be created for each IMG 2020
Related Topics and Dependencies
IMG 1010 - Configuring a Synchronization Priority List
Field Descriptions
Timing List
The priority in which the IMG 2020 will use the timing ports is configured here. The priority is displayed from top to bottom. The top most entry gets the highest or first priority and then the priority decreases as you move to the bottom. The priority can be changed by moving the entries up or down in the list. Highlight which entry to move and select the Up or Down arrow button and the entry will move accordingly. See screen capture below.
Moves highlighted entry up or down one space at a time
Moves highlighted entry from existing position to either the top or bottom space.
Note: The Primary Reference and Secondary Reference entries use a loop timing source such as T1 or E1. It will not accept an external clock source such an atomic clock. The IMG 2020 gets its timing from a T1/E1 signaling type timing source only.
Below is an explanation of each timing reference and how the IMG 2020 uses them.
Timing Source | Description |
Primary Reference | Primary Reference is hard-coded to the DS-1 within interface 0. This interface is one of four interfaces that are labeled T1/E1. The timing source does not need to be configured. Connect a DS-1 to this interface and the IMG 2020 will automatically synchronize with the T1 or E1 loop timing source. |
Secondary Reference | Secondary Reference is hard-coded to the DS-1 within the interface 1. This interface is one of four interfaces that are labeled T1/E1. The timing source does not need to be configured. Connect a DS-1 to this interface and the IMG 2020 will automatically synchronize with the T1 or E1 loop timing source. |
Primary Loop | Primary Loop timing can be configured on any DS-1 other than the DS-1's used for Primary and Secondary Reference timing described above. To configure, select the Bearer Span object. In the Object Table at bottom of pane, select one of the DS-1's. Right click and select Set Primary. Once the timing source is set, the Primary Loop selection in the Timing Synchronization Priority List can be moved to a higher position as required. |
Secondary Loop | Secondary Loop timing can be configured on any DS-1 other than the DS-1's used for Primary and Secondary Reference timing described above. To configure, select the Bearer Span object. In the Object Table at bottom of pane, select one of the DS-1's. Right click and select Set Secondary. Once the timing source is set, the Secondary Loop selection in the Timing Synchronization Priority List can be moved to a higher position as required. |
Free Running | The Free Running source is the clock source generated internally. It is not recommended that the Free Running source be used as an external clock source used to time the network. The Free Running source is used as a backup source in the event all network timing sources have failed. The Free running timing source should always be configured as one of the top 5 clock sources in the Timing Synchronization Priority List. Preferably, the Free Running timing source should always be set to the 5th position in this list. |
Optical Working | The timing source labeled Optical Working is configured on the optical interface labeled W on the rear of the IMG 2020. Timing is synced to the optical streams of the Working interface. To configure, select the Timing Synchronization Priority List and move the Optical Working selection to the top of the list. When the optical interface is being utilized, the optical working and optical protection timing sources must be configured as the first and second timing sources in the Timing Synchronization Priority List. |
Optical Protection | The timing source labeled Optical Protection is the redundant optical interface and is configured on the optical interface labeled P on the rear of the IMG 2020. Timing is synced to the optical streams of the Protection interface. To configure, select the Timing Synchronization Priority List and move the Optical Protection selection to the second position from the top of the list. |