Avaya Media Processing Server 1000 Hardware Installation And Maintenance page 180

Operation and Administration
TMS PLL
The TMS PLL is used for clocking and frame synchronizations between the TMS DCC with an
external network. The TMS PLL is also used to synchronize the audio paths between TMS when
bridging calls.
Clocking is provided through a pair of redundant clocks labeled reference clock A and reference
clock B (that is, RefA and RefB). System clocks are configured in the tms.cfg file, which is unique to
each installation. Each clock can be derived from any of the spans on the TMS DCC although only
span is used at any given time.
In multi-chassis installations each clock can be driven by any span in a single chassis. Again the
tms.cfg file must contain the appropriate synchronization list configuration for a site. The selection of
a specific span as a reference is under software control of the TMS and NIC.
Because the TMS relies on a set of redundant clocks a system is functional as long as one of the
clocks is available. Failure of either clock generates a minor alarm. If no clock is available, then a
major alarm is generated.
For installations with a single TMS only one clock is configured. Typically RefA and the alarm from
the redundant clock (RefB) is masked. Redundancy for this configuration is provided by having more
than one span configured as a reference source in the tms.cfg file.
Distribution of clocking in multi-chassis configurations is provided by the NICs. A NIC failure can
affect clock distribution.
Clocking Failure Effects
Loss of all reference clocking on the TMS causes the TMS to enter a free run on the PLL. In free run
the TMS is no longer synchronized with the external network and generates frame sync errors
between the TMS-DCC and the network. The result is noisy or no audio on a channel.
For multi-TMS installations, the loss of clocking causes each TMS to enter a free run state and to
loose synchronization on the audio paths between the cards. When the TMS are not synchronized
to a common clock source, the audio between the cards is noisy or nonexistent.
Recovery from Clocking Failure
The TMS and NIC software can recover or re synchronize themselves when a loss of clock occurs.
It is normal for the system to enter a major alarm state after a restart and when no clock sources are
available. The system automatically recovers from the alarm conditions after TMS spans go into
service. Do not start applications while the system is in the major alarm state for the PLL.
Note:
The system can be in this alarm state for several minutes before recovering.
A system can temporarily enter an alarm state for the PLL if the span on the TMS that is providing
the clock is no longer in service.
However, if a minor or major alarm condition persists for more than the expected seconds, you must
resolve the problem as detailed in the diagnostics for the TMS PLL, see
page 175.
The following modules can be affected:
• TMS PLL
• TMS DCC
Avaya Media Processing Server 1000 Hardware Installation and Maintenance
180
Comments? infodev@avaya.com
TMS Diagnostics on
October 2014