Setting G700 Synchronization

If the Avaya G700 Media Gateway contains an MM710 T1/E1 Media Module, it is usually advisable to set the MM710 up as the primary synchronization source for the G700. In so doing, clock sync signals from the Central Office (CO) are used by the MM710 to synchronize all operations of the G700. If no MM710 is present, it is not necessary to set synchronization.

If Communication Manager is running on an Avaya S8300 Media Server, however, the usual SAT screens for "display sync" and "change sync" are not present. Clock synchronization is set via the Media Gateway Processor (MGP) command line interface (CLI). The command (in configure mode) set sync interface {primary | secondary} {<mmID> | [<portID>]} defines a potential stratum clock source (T1/E1 Media Module, ISDN-BRI).,

where <mmID> is the Media Module ID of an MM stratum clock source of the form "vn", where "n is the MM slot number, and

For the MM720 BRI Media Module, <portID> is formed by combining the mmID of the MM to the 2-digit port number of the BRI port.

By setting the clock source to primary, normal failover will occur. Setting the source to secondary overrides normal failover, generates a trap, and asserts a fault. The identity of the current sync source in use is not stored in persistent storage. Persistent storage is used to preserve the parameters set by this command.

Control of which reference source is the "Active" source is accomplished by issuing the command set sync interface {primary | secondary}. If "secondary" is chosen, then the secondary source becomes "Active", and the primary becomes "standby", and, in addition, fallback to the primary source will not occur if or when it becomes available.

If neither primary nor secondary sources are identified, then the local clock becomes "Active".

Use the following procedure:

1. Login at the Welcome to Media Gateway Server menu.
   You are now logged-in at the Supervisor level on the Media Gateway Processor. The prompt appears as MG-mmm-1(super)>, where mmm is the administered G700 Media Gateway number in the network.
2. Type configure to access the configuration prompt.
   The prompt will change to indicate that you are in configuration mode. In the configuration mode, you may use the set commands.
3. At the prompt, type set sync interface primary <mmid>.
   The MM710 Media Module is now configured as the primary clock synchronization source for the G700 Media Gateway.
4. At the prompt, type set syn sou pri.

If the G700 Media Gateway contains a second MM710 Media Module, type set sync interface secondary.
If, for any reason, the primary MM710 Media Module cannot function as the clock synchronization source, the system defaults to the secondary MM710 Media Module for that function. If neither MM710 Media Module can function as clock synchronization source, the system defaults to the local clock running on the S8300 Media Server.

The YELLOW ACT LED on the front of the MM710 Media Module can tell you the status of that module regarding synchronization.

• If the YELLOW ACT LED is solidly on or off, it has NOT been defined as a synchronization source. If it is on, one or more channels is active. If it is an ISDN facility, the D-channel will count as an active channel and will cause the YELLOW ACT LED to be on.
• When the MM710 is driving a clock sync source line to the G700 main clock, the YELLOW ACT LED does not indicate port activity, but instead indicates that the MM710 is the sync source by flashing with a regular 3-second period:
• It is on for 2.8 seconds and flashes off for 200 milliseconds if it has been specified as a sync source and is receiving a signal that meets minimum requirements for the interface.
• If it has been specified as a sync source and is not receiving a signal, or is receiving a signal that does not meet minimum requirements for the interface, then the YELLOW ACT LED will be off for 2.8 seconds and flash on for 200 milliseconds.