ZyXEL Communications MSC1000G Series, User Manual

Page: 819 / 1168

Chapter 29 port Commands
Management Switch Card User’s Guide
819
where
This command sets the transmission convergence mode for the specified SHDSL port(s). IEEE
802.3-2004’s EFM (Ethernet First Mile) lets you run Ethernet protocol over G.SHDSL. EFM framing
has less overhead than ATM encapsulation, thus allowing better data transmission rates.
If the CPE device supports EFM, select
efm
to use Ethernet frames over SHDSL. For ports set to EFM
mode you can use PAF (PHY Aggregation Function) to bundle EFM PHYs to either increase the data
rate of one logical EFM link for a given loop length or increase the maximum achievable loop length
for a given data rate. Configure PAF EFM bundling in the G.bond settings (see
Section 29.11 on
page 792 ).
If the CPE device only supports
ATM
, select atm to use ATM cells over SHDSL. For ports set to ATM
mode, you can use G.bond to create bundles of up to 16 wires (see Section 29.11 on page 792 ).
29.30.3 port shdsl pbo Command
Syntax:
port shdsl pbo < slot-port > normal_epl|forced_epl|forced_no_epl < value >
where
This command sets the power backoff feature setting on the specified SHDSL port(s). 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.
atm|efm
=
efm
: Use Ethernet frames inside SHDSL framing.
atm
: Use ATM cells inside SHDSL framing.
normal_epl|forced_
epl|forced_no_epl
=
normal_epl
: 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.
forced_epl:
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.
forced_no_epl
: 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).
< value >
=
This sets the 0~31 in dB.
When using
nornal_epl
or
forced_epl
, this sets the maximum
power backoff value.
When using
forced_no_epl
, this sets the power backoff value.