ZyXEL Communications ALC1024, Руководство пользователя

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Web Configurator with MSC
29-2 ADSL Port Setup
configuration maximum and minimum transfer rates. You still get to individually enable or disable each port, as
well as configure its channels and operational mode. See later in this chapter for how to configure profiles.
29.4 Interleave Delay
Interleave delay is the wait (in milliseconds) that determines the size of a single block of data to be interleaved
(assembled) and then transmitted. Interleave delay is used when transmission error correction (Reed- Solomon) is
necessary due to a less than ideal telephone line. The bigger the delay, the bigger the data block size, allowing
better error correction to be performed.
Reed-Solomon codes are block-based error correcting codes with a wide range of applications. The Reed-Solomon
encoder takes a block of digital data and adds extra "redundant" bits. The Reed-Solomon decoder processes each
block and attempts to correct errors and recover the original data.
29.4.1 Fast Mode
Fast mode means no interleaving takes place and transmission is faster (a “fast channel”). This would be suitable if
you have a good line where little error correction is necessary.
29.5 Configured Versus Actual Rate
You configure the maximum rate of an individual ADSL port by modifying its profile (see the ALC Edit Profile
screen) or assigning the port to a different profile (see the ALC Edit Port Setup screen). However, due to noise
and other factors on the line, the actual rate may not reach the maximum that you specify.
Even though you can specify arbitrary numbers using the ALC Edit Profile screen, the actual rate is always a
multiple of 32 Kbps. If you enter a rate that is not a multiple of 32 Kbps, the actual rate will be the next lower
multiple of 32Kbps. For instance, if you specify 60 Kbps for a port, the actual rate for that port will not exceed 32
Kbps, and if you specify 66 Kbps, the actual rate will not be over 64Kbps.
29.6 Default Settings
The default profile always exists and all of the ADSL ports use the default profile settings when the ADSL line card
is shipped. The default profile's name is set to
DEFVAL
. The default profile’s maximum downstream rate can only
be obtained when using the G.dmt standard. Configure a profile with a maximum downstream rate of 1536 Kbps or
less for use with G.lite.
Refer to the ALC1024 Overview chapter for the settings of the default profile and ADSL port default settings.
29.7 ALC Port Setup Screen
Click Port Setup in the navigation panel to open the Port Setup screen.
Click the ADSL line card’s link in the Port Setup screen to open that card’s Port Setup screen.