H3C 20-20, Command Reference Manual

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Use undo tdm-clock command to restore the default.
By default, the TDM clock source for an E1 or T1 interface is the internal clock.
When digital voice E1/T1 interfaces perform TDM timeslot interchange, it is
important for them to achieve clock synchronization to prevent frame slips and bit
errors.
Depending on your configurations on E1/T1 interfaces, the system adopts
different clocking approaches. When there is a subcard VCPM on the mainboard,
the clock distribution principle is as follows:
■
If the line keyword is specified for all interfaces, the clock on the interface with
the lowest number is adopted. In case the interface goes down, the clock on
the interface with the next lowest number is adopted.
■
If the line primary keywords are specified for one interface, the clock on the
interface is adopted. In one system, you can do this on only one interface.
■
If the line keyword is specified for one interface and the internal keyword for
all others, the clock on the interface is adopted.
■
Normally, you cannot set the clock source for all interfaces in a system to
internal. This is to prevent frame slips and bit errors. You can do this however if
the remote E1/T1 interfaces adopt the line clock source.
When there is no VCPM on the mainboard, the configuration of each MIM/FIC is
independent but only one interface is allowed to be set to line primary on the
same device.
Example # Set the TDM clock source on interface E1 1/0 to line clock.
<Sysname> system-view
[Sysname] controller e1 1/0
[Sysname-e1 1/0] tdm-clock line
timer dl
Syntax
timer dl { answer | clear-back | clear-forward | seizure | re-answer | release-guard }
time
undo timer dl { answer | clear-back | clear-forward | seizure | re-answer |
release-guard }
View R2 CAS view
Parameter answer time : Timeout time in milliseconds of R2 answer signal, in the range of
100 to 120,000 with a default of 60,000. After the originating point sends a
seizure acknowledgement signal, the terminating point should send back an
answer signal within the timeout time. If the terminating point fails to send an
answer signal within the timeout time, the originating point will clear the
connection. Timeout time of R2 answer signal should be configured at both the
originating point and the terminating point. The timeout time of answer signals
from the terminating point is configured at the originating point, while the