Westermo DDW-100 - Manual (Page 7)

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Description
Functional description
SHDSL represents the best of several symmetric DSL technologies that have been com-
bined into a single industry standard. The DDW-100 is designed as a transparent Ethernet
Extender (Ethernet Bridge) for 10/100BaseTX networks. It is transparent for multicast
addressing, VLAN packets, VPN pass-through for IPSec and for protocols like MODBUS/
tcp and Profinet.
SHDSL allows the re-use of existing twisted copper pair with data rates from 192 kbit/s
to 2.3 Mbit/s in both directions (Symmetric DSL), according to standard ITU-T G.991.2.
Based on the quality of the line and the communication speed, distances up to 10 km can
be achieved, this however depends of the quality of the line and cable characteristics.
This differs from application to application, therefore a unique feature is implemented
providing reliable-, normal-, or high speed mode.
Distance on /data rate without noise, cable type is AWG24, 0,2 mm 2
Tested distances with Cat 5 cables
192 kbit/s >6 km
384 kbit/s >6 km
512 kbit/s >6 km
768 kbit/s >6 km
1024 kbit/s >3 km
1280 kbit/s > 3 km
2048 kbit/s > 3 km
2304 kbit/s > 3 km
Distances up to 10 km at 192 kbit/s have also
been verified with a 1mm
2 cable.
Description of used nomenclature:
Noise margin:
The margin between signal and noise (dB)
CO/CPE:
CO (Central Office) answering central unit, the CO configures the CPE when establish-
ing a connection. CPE (Customer Premises Equipment) is the unit that initiates the con-
nection.
Annex A and B:
Annex A in ITU-T Rec. G.991.2 describes those specifications that are unique to SHDSL
systems operating under conditions such as those typically encountered within North
American networks.
Annex B in ITU-T Rec. G.991.2 describes those specifications that are unique to SHDSL
systems operating under conditions such as those typically encountered within European
networks.