Permanent Virtual Circuits - ZyXEL Communications MSC1024G Series User Manual

Table 100 SHDSL Port Setup: Advanced (continued)
LABEL
Stur Alarm Profile
Customer Info
TEL
SHDSL Feature
Power Backoff
The Negotiated
Noise Margin
Mode
Apply
Cancel

11.11 Permanent Virtual Circuits

A Permanent Virtual Circuit (PVC) is a logical point-to-point circuit between sites. PVCs are
low-delay circuits because routing decisions do not need to be made along the way. Permanent
means that the circuit is pre-programmed by the carrier as a path through the network. It does
not need to be set up or torn down for each session. PVCs are also called virtual channels.
MSC1000G/1024G/1224G Series User's Guide
DESCRIPTION
Select an alarm profile to define the thresholds that trigger an alarm on the port
when exceeded. This alarm profile is for the STU-R (SHDSL Termination Unit -
Remote) end point.
Enter information to identify the subscriber connected to this ADSL port. You can
use up to 31 printable English keyboard characters (including spaces and
hyphens).
Enter information to identify the telephone number of the subscriber connected to
this ADSL port. You can use up to 15 English keyboard characters (including
spaces and hyphens).
This command sets the power backoff feature setting on the SHDSL port. Power
backoff calculates how much power is needed for the connection. This allows the
STU-C and STU-R to use only enough power for the port's maximum transmission
rate (configured in the SHDSL profile). You can normally just leave the default
setting (NORMAL_EPL), you only need to use this command if the STU-R does
not support EPL or you need to configure the port to use a specific power backoff
setting.
Select NORMAL_EPL to use power backoff with EPL (Estimated Power Loss).
Each end calculates an EPL and uses it in determining a power backoff value for
the other end to use.
Select FORCED_EPL to use forced power backoff with EPL. The STU-C
calculates an EPL and uses it in determining the power backoff values for both
ends. This can be used when the STU-R device does not support EPL.
Select FORCED_NO_EPL to use forced power backoff without EPL. The STU-C
uses the value you specify in determining the power backoff values for both ends.
This can be used when you have prior knowledge about the physical line (loop).
Set the power backoff value (0~31 in dBm).
When using NORMAL_EPL or FORCED_EPL, this sets the maximum power
backoff value.
When using FORCED_NO_EPL, this sets the power backoff value.
Specify how the target noise margin value is acquired.
Select normal to have each end of the connection determine the target noise
margin to be used by the other end.
Select forced to set the upstream and downstream parameters according to the
target noise margin value set in the SHDSL profile.
Click Apply to save the changes in this screen to the system's volatile memory.
The system loses these changes if it is turned off or loses power, so use the
Config Save on the navigation panel and then the Save button to save your
changes to the non-volatile memory when you are done configuring.
Click Cancel to begin configuring the fields again.
Chapter 11 Subscriber Port Setup Screens
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