ZyXEL Communications MSC1000G User Manual page 220

Chapter 9 Subscriber Port Setup Screens
Figure 134 ADSL Port Setup: Advanced: Option Mask
The following table describes the fields in this screen.
Table 97 ADSL Port Setup: Advanced: Option Mask
LABEL
ALL
Disable Trellis
Disable Reed
Solomon
Disable
Upstream/
Downstream
Bitswap
Disable 1-bit
Constellation
Disable Transmit
Windowing
Disable s=0.5
Support(ADSL1
Only)
Disable G.lite
Rate Limit
(ADSL1 Only)
Disable nitro
mode
Current Option
mask is:
Apply
Cancel
220
DESCRIPTION
Use the check boxes to disable individual features. Use the All check box to select every
feature check box.
Trellis encoding helps to reduce the noise in ADSL transmissions. Trellis may reduce
throughput but it makes the connection more stable.
Reed-Solomon performs transmission error correction.
Bit swapping allows the system to respond to noise on a tone by sending it's data on
another tone. The subscriber (ATU-R) equipment must also support this in order for it to
work.
1-bit constellation allows the system to send individual bits over DMT tones that can only
support one bit. This allows the connection to use as many of the tones as possible.
Transmit windowing is only available with ADSL2+.
0.5 support maps two Reed-Solomon code words into one data frame (instead of one) to
increase the maximum G.dmt transmission rate.
Disabling the G.lite rate limit allows the G.lite upstream transmission rate to be greater
than 512 Kbps.
In nitro mode, the system compresses the ADSL2+ ATM header so fewer bits need to be
transmitted. It additionally increases the DSL connection speed. However, the connected
CPE device should also support this to make it work. Select this to disable the nitro mode.
Selecting or clearing feature check boxes adjusts the current option mask displayed at the
bottom of the screen.
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 link
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 close the screen without saving your changes.
Management Switch Card User's Guide