ZyXEL Communications IES-1000 - Interleave Delay; Fast Mode; ADSL Configured Versus Actual Rate; ADSL Module Default Settings

IES-1000 User’s Guide
11-2 ADSL Module Port Setup
11.5 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.
11.5.1 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.
11.6 ADSL Configured Versus Actual Rate
You configure the maximum rate of an individual ADSL port by modifying its profile (see the ADSL Edit Profile
screen) or assigning the port to a different profile (see the ADSL 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 ADSL 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.
11.7 ADSL Module Default Settings
The default profile always exists and all of the ADSL ports use the default profile settings when the AAM-1008 is
shipped. The default profile's name is
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.
11.7.1 Default Profile Settings
The following are the settings of the default profile.
- Name: DEFVAL
- Profile Status: Active
Downstream ADSL settings:
- Latency Delay: 4ms
- Target Signal/Noise Ratio: 6 db