Structured Versus Unstructured Summary - 3Com SuperStack II PathBuilder S330 Reference Manual

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 192.
Figure 192 DS1 Unstructured Tunneling
Data
Service
Unit
Channel
Service
Unit
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.

Structured versus Unstructured Summary

Use Table 36 to determine whether to use structured or unstructured DS1 CBR.
Table 36 When to use Structured Versus Unstructured Service
T1
Unstructured
DS1 Signal Tunneled Through a PVC
DS0 midspan drop and insert
DS0 access grooming
DS1 network management end to end
DS1 end to end (no DS0 access)
DS1 CBR 1.536 Mbps of bandwidth
DS1 CBR 1.544 Mbps of bandwidth
Dynamic Bandwidth Allocation (DBA)
ATM Network
Structured
CBR Module 263
Data
Service
Unit
Channel
Service
Unit
Unstructured
X
X
X
X X
X X
X
X