ZyXEL Communications SAM1316-22, User Manual

Page: 107 / 464

SAM1316-22 User’s Guide
107
C
H A P T E R
1 4
xDSL Profiles Setup
A profile is a list of settings that you define. Then you can assign them to one or
more individual ports. For background information about many of these settings,
see
Chapter 13 on page 91 .
14.1 Configured Versus Actual SHDSL Rates
You configure the maximum and minimum rates of individual SHDSL ports using
the set profile command. 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 in the set profile command, the
actual rate is always a multiple of 64 Kbps. If you enter a rate that is not a
multiple of 64 Kbps, the actual value will be the next lower multiple of 64Kbps. For
instance, if you specify 2100 Kbps for a port, the actual value will be 2048 Kbps,
and if you specify 2120 Kbps, the actual value will be 2112 Kbps.
Note that when you configure a DSL profile, the upstream and downstream speeds
are the same. The minimum rate must be less than or equal to the maximum rate.
14.2 N-wire Mode
The n-wire mode allows you to physically bundle two SHDSL ports into a single 4-
wire connection. The 4-wire mode is described in ITU-T G.991.2. You can use it to
connect to SHDSL modems or routers that also support 4-wire mode. N-wire mode
also allows you to physically bundle four SHDSL ports into a single 8-wire
connection. The 8-wire group is called mpair4.
N-wire mode can increase the reach of a particular data rate without having to
regenerate the signal. It can also give increased bandwidth for LAN-to-LAN
applications.
When using 4 or 8-wire groups, you must apply the same DSL profile to every port
in a specific set of ports. For example, a profile for a 4-wire group can be used