ZyXEL Communications IES-708-22A - Manual (Page 117)

IES-708-22A User’s Guide
117
C
H A P T E R
14
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 103 .
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 with ports 1,2 or 3,4
but not with ports 2,3 or 4,5. A profile for an 8-wire group can be used with ports 1,2,3,4 or
5,6,7,8 but not with ports 2,3,4,5 or 4,5,6,7.
After you assign the same DSL profile to all the ports in the set, you only have to configure the
one with the highest port number. Its settings apply to all the ports in the set. For example, if
you create an 8-wire group with ports 5, 6, 7, and 8, all the settings for port 8 apply to ports 5,
6, and 7 (regardless of whatever settings might already exist for ports 5, 6, and 7).