ZyXEL Communications IES-1248-51 - Page 366

IES-1248-51/51A/53 User’s Guide
366 Chapter 55 ADSL Commands
The profile is a table that contains information on ADSL line configuration. Each entry in this
table reflects a parameter defined by a manager, which can be used to configure the ADSL
line.
Note that the default value will be used for any of the above fields that are omitted.
The upstream rate must be less than or equal to the downstream rate.
Even though you can specify arbitrary numbers in the profile set command, 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.
The ADSL up/down shift noise margins define the threshold that triggers rate adaptation. For
example:
The target SNR is 6, and the up/down shift noise margins are 9/3.
If the signal becomes better and the SNR is higher than 9, rate adaptation is triggered and the
line rate becomes higher
If the signal becomes bad and the SNR is lower than 3, rate adaptation is triggered and the line
rate becomes lower.
The following example creates a premium profile (named gold) for providing subscribers with
very high connection speeds and no interleave delay. It also sets the upstream target signal/
noise margin to 5 db, the upstream minimum acceptable signal/noise margin to 0 db, the
upstream maximum acceptable signal/noise margin to 30 db, the upstream minimum ADSL
<down target
margin>
=
The target ADSL downstream signal/noise margin (0-31db).
<down min
margin>
=
The minimum acceptable ADSL downstream signal/noise
margin (0-31db).
<down max
margin>
=
The maximum acceptable ADSL downstream signal/noise
margin (0-31db).
<down min rate> =
The minimum ADSL downstream transmission rate (32-32000
Kbps).
<up down shift
margin>
=
The upstream down shift noise margin (0~31 in dB).
<up up shift
margin>
=
The upstream up shift noise margin (0~31 in dB).
<down down
shift margin>
=
The downstream down shift noise margin (0~31 in dB).
<down up shift
margin>]
=
The downstream up shift noise margin (0~31 in dB).