INSTALLATION
Page 18
DOC_DEV_XSRACK_User guide_A
6.4
Protecting the SHDSL switch from lightning
The XSRACK is coupled to the line by a transformer which provides isolation between the circuit board and the
line. Moreover, the XSRACK is equipped with internal protections against overvoltage.
However, if the line is vulnerable to thunderstorms, for example if it is an air line, or if it is several kilometers
long, or if the installation is in a very exposed area, it is recommended to protect each XSRACK with a surge
protector connected to the earth.
7
Connecting the XSRACK to the line
7.1
General precautions
The SHDSL signal is not polarized; the two wires of the twisted pair can be interchanged.
Check that the shield, if any, is properly earthed.
7.2
Point to point connection using two, three or four twisted pairs
An aggregated link is a link between two SHDSL switches that uses two or three or four twisted pairs to multiply
the total throughput.
Aggregation is only possible for pairs in the same slot.
When performing a point to point link to doubled or tripled or quadrupled the data rate, it is recommended to
wire pairs in an orderly way, as shown below, to make the configuration and the diagnostic easier.
XSRACK
XSLAN
Port 1
Port 2
Port 3
Port 4
Port 1
Port 2
Port 3
Port 4
