Wheelchair User Manual

Configuring OC3-ATM Cards (MAX TNT/DSLTNT)
Using OC3-ATM ports as a clock source
APX 8000/MAX TNT/DSLTNT Physical Interface Configuration Guide Preliminary May 9, 2000 15-3
Using OC3-ATM ports as a clock source
OC3-ATM profiles support Clock-Source and Clock-Priority parameters for specifying
whether the port can be used to source the ATM network clock signal and feed it to the shelf
controller as the master clock for the unit. Each OC3-ATM port can be configured as eligible
or ineligible for this use, and can be assigned a high, middle, or low priority for being elected
as the clock source.
If more than one line is eligible to be the clock source, the system chooses the one with the
highest priority, as specified by the Clock-Priority setting. If multiple sources of equal priority
are present, the system selects the first valid clock source. (A clock source is valid if the
Clock-Source parameter is set to
eligible and the OC3-ATM interface is synchronized.)
Once it has selected a clock source, the system uses that source until the source becomes
unavailable or a higher-priority source becomes available. If no eligible external sources are
available, the system uses an internal clock generated by the shelf controller.
Tx-Cell-Payload-
Scramble-Disabled
Enable/disable scrambling of the 48-byte ATM cell payload in
transmitted cells. This function is enabled by default. Disable it by
setting this parameter to yes only if the far-end switch has
disabled the corresponding functions.
Loop-Timing Enable/disable derivation of transmission timing from receiver
inputs. Loop timing is enabled by default. If the parameter is set to
No, transmission timing is derived from the reference clock
instead.
VPI-VCI-Range Valid range of VCI numbers to be used with specified VPIs for
virtual channel connections (VCCs). For details about setting the
VPI-VCI range, see the APX 8000/MAX TNT/DSLTNT ATM
Configuration Guide.
Clock-Source Enable/disable obtaining the system clock signal from the port. By
default, ports are not eligible clock sources. For information about
using an OC3-ATM line as the source for the system clock, see
“Using OC3-ATM ports as a clock source” on page 15-3.
Clock-Priority
Priority of the interface as the system’s clock source: high, middle,
or low priority. Once the TAOS unit unit chooses a clock source, it
uses that source until the interface becomes unavailable or a
higher-priority source becomes available.
Traffic-Shapers Settings for shaping traffic on the interface. For details, see the
APX 8000/MAX TNT/DSLTNT ATM Configuration Guide.
Tx-Scramble-Disabled Enable/disable scrambling and descrambling of the entire transmit
and receive stream. This function is enabled by default. Disable it
only if the far-end switch has disabled the corresponding
functions.
Tx-Cell-Payload-
Scramble-Disabled
Enable/disable scrambling and descrambling of the 48-byte ATM
cell payload in transmitted and received cells. This function is
enabled by default. Disable it only if the far end switch has
disabled the corresponding functions.
Parameter Specifies