3Com 3C63100-AC-C - PathBuilder S600..., Reference Manual

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90 C
HAPTER
4: P
ATH
B
UILDER
S600 M
ODULE AND
A
PPLICATION
O
VERVIEW
Drop-and-Insert DS0 channels can also be allowed to transit the entire path. This
provides DS0 to DS0 connectivity between end locations. Structured DS0s can be
groomed to be combined through an ATM network allowing end to end DS0
switching as shown in Figure 52.
Figure 52 Structured DS0 Combining
Dynamic Bandwidth Allocation (DS0 Signaling)
Structured DS0s provide channel associated signaling (CAS) by providing a path
for DS0 A and B bits. See Figure 53.
Channel associated signalling allows telephone supervision to be signaled end to
end. Note that structured DS1 CBR occupies only the needed bandwidth for the
DS0s selected.
Figure 53 Channel Associated Signaling
These frames are then followed by the ABCD bits of each active DS0. Two DS0s
ABCD bits are provided in each byte after the last DS0 group. Figure 54 illustrates
an example of 3 DS0s and their ABCD bits sent in a structured encapsulation.
DS1
DS1
Up to 24 Timeslots
ATM Network
10 DS0
10 DS0
PBX - Private Branch Exchange
VCC - Virtual Channel Connection
Structured DS0
Grooming
PathBuilder S600
PathBuilder S600
PathBuilder S600
DS0
A&B Bits
Channel Associated
Signaling (CAS)
Channel
Bank
PathBuilder S600 PathBuilder S600