DT Etherlink IV
User Manual
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G. 703 (E1-1)
G. 703 (E1-1)
Customer Premises Equipment
Central Office
ETH1
Ethernet
Network
ETH1
Ethernet
Network
DSL1
DSL2
G. 703 (E1-2)
G. 703 (E1-3)
G. 703 (E1-2)
G. 703 (E1-3)
ATS
ATS
X
X
X
X
X
DSL1 Up, DSL2 Down
E1-1 , 57 TS WAN
Transmitted via DSL1
Nothing transmitted
via DSL2
SA-RC-ETHERLINK_II_4DSL-4E1-4ETH
SA-RC-ETHERLINK_II_4DSL-4E1-4ETH
S-Access
Etherlink_II
LTU
S-Access
Etherlink_II
LTU
G. 703 (E1-1)
G. 703 (E1-1)
Customer Premises Equipment
Central Office
ETH1
Ethernet
Network
ETH1
Ethernet
Network
DSL1
DSL2
G. 703 (E1-2)
G. 703 (E1-3)
G. 703 (E1-2)
G. 703 (E1-3)
ATS
ATS
X
X
X
X
X
DSL1 Down, DSL2 Up
Nothing transmitted
via DSL1
E1-1 , 57 TS WAN
Transmitted via DSL
2
SA-RC-ETHERLINK_II_4DSL-4E1-4ETH
SA-RC-ETHERLINK_II_4DSL-4E1-4ETH
S-Access
Etherlink_II
LTU
S-Access
Etherlink_II
LTU
Figure 3.7 Example of reservation
While for a two SHDSL channels system in case of a failure the substitution of channels is
“trivial”, in
three and four SHDSL channels system different variants are possible. However, any system using
the reservation mode follows a strict logic in channel substitution. The next table illustrates the logic
of channel reservation with 2/3/4 SHDSL interfaces.
The table for four DSL channels is constructed based on the assumption that communication in one
channel is lost frequently, while communication in two channels occurs less frequently. Usually a
loss of communication occurs successively, i.e., the first channel fails and then the next channel
fails. The logic and rules for channel substitution are made to minimize the number of channel
switching (especially high-priority channels) to minimize the data losses.
