Paradyne 7974 User Manual page 114

A. Configuration Options
Table A-6. Synchronous Data Port Options for Model 7975 (2 of 4)
A-10
Payload Rate
Possible Settings: 64, 128, 192, 256, 320, 384, 448, 512, 576, 640, 704, 768, 832, 896,
960, 1024, 1088, 1152, 1216, 1280, 1344, 1408, 1472, 1536, 1600, 1664, 1728, 1792,
1856, 1920, 1984, 2048
Default Setting: [Highest multiple of 64 Kbps supported by the DSL Line Rate]
NOTE: Payload rates of 1088 Kbps and higher pertain only to 2 Mbps models.
Specifies the payload rate of the port. This option is not displayed on the unit when
AutoRate is enabled or the unit is configured as an NTU. The LTU configures the payload
rate for the NTU. The highest multiple of 64 Kbps is used when Autorate is enabled.
64 – 2048 – Sets the payload rate in Kbps when AutoRate is disabled (unit is configured
as fixed rate).
Transmit Clock Source
Possible Settings: Internal, External
Default Setting: Internal
Specifies whether the transmitted data for the synchronous data port is clocked using an
internal clock provided by the LTU or an external clock provided by the DTE connected to
the synchronous data port.
T
Transmit Clock Source is available only when the unit is configured as an LTU.
Internal – Indicates the clock is provided internally by the termination unit on the TXC
interchange circuit DB (CCITT 114).
External – Indicates the clock is provided externally by the DTE on the XTXC interchange
circuit DA (CCITT 113). Use this selection if the clock source is set to the data port.
Invert Transmit Clock
Possible Settings: Disable, Enable
Default Setting: Disable
When configured as the LTU and Transmit Clock Source is set to External, specifies
whether the clock supplied by the the unit on the TXC interchange circuit DB (ITU-T 114)
is phase inverted with respect to the Transmitted Data interchange circuit BA (ITU-T 103).
This configuration option is useful when an excessive cable length between the unit and
the DTE causes errors.
Disable – Indicates TXC supplied by the unit on this port is not phase inverted.
Enable – Indicates XC supplied by the unit on this port is phase inverted.
December 2001 7900-A2-GB21-20