3com S330 ユーザーズマニュアル
CBR Module
237
Unstructured DS1
Implement unstructured DS1 service when you want DS1 tunneling through an
ATM system. DS1 tunneling allows an entire DS1 frame, including framing bits, to
travel across an ATM network. See Figure 176.
ATM system. DS1 tunneling allows an entire DS1 frame, including framing bits, to
travel across an ATM network. See Figure 176.
Figure 176 DS1 Unstructured Tunneling
Use unstructured services when DS0 midspan access is not required and
end-to-end DS1 service is required; for example, to provide CSU or DSU
end-to-end connectivity. The encapsulation of unstructured DS1 occupies DS1
bandwidth on the VCC and uses AAL 1 SAR.
end-to-end DS1 service is required; for example, to provide CSU or DSU
end-to-end connectivity. The encapsulation of unstructured DS1 occupies DS1
bandwidth on the VCC and uses AAL 1 SAR.
Structured versus Unstructured Summary
Use Table 32 to determine whether to use structured or unstructured DS1 CBR.
ATM Network
Data
Service
Unit
Data
Service
Unit
Channel
Service
Unit
Channel
Service
Unit
T1
Unstructured
DS1 Signal Tunneled Through a PVC
Table 32 When to use Structured Versus Unstructured Service
Structured
Unstructured
DSO midspan drop and insert
X
DSO access grooming
X
DS1 network management end to end
X
DS1 end to end (no DSO access)
X
X
DS1 CBR 1.536 Mbps of bandwidth
X
X
DS1 CBR 1.544 Mbps of bandwidth
X
Dynamic Bandwidth Allocation (DBA)
X