User`s guide

OVERVIEW
XSRING+ SHDSL switch User’s guide ref 9018809-01 Page 11
3.3 The by-pass function
When the network is a daisy chain – that case is very frequent in industrial applications - and when,
however, it is not possible to build a failsafe structure like a ring, the XSRING+BP offers a very useful
function called the “By-pass function”.
The XSRING+BP includes an electro-mechanical relay between both lines; that relay is automatically
closed to connect the two lines when the XSRING is switched off.
For instance, if the XSRING #2 cabinet is switched off for maintenance, for instance, the by-pass relay
inside the XSRING #2 will automatically connect the line coming from the XSRING #1 to the line going
to the XSRING #3.
After a few seconds, the XSRING #1 detects the connection default and establishes immediately the
connection with the XSRING #3.
In that way, the connection is recovered after a short delay between the XSRING+ #1 and the
XSRING+ #3.
3.4 Data rate versus distance
Each interface features an adaptive data rate from 128 Kb/s up to 5,7 Mb/s.
The data rate is a function of the cable quality and the distance with the next SHDSL switch. For
instance, the maximum distance between 2 switches through a line is 13 Km (8 miles) with a 0.9 mm
wire diameter cable.
The table in appendix 1 gives the data rate which can be expected over a line versus the length of the
line.
3.5 Ethernet ports
The XSRING provides 2 or 4 Ethernet RJ45 interfaces (depending on the product reference).