cx29600 Mindspeed Technologies, cx29600 Datasheet - Page 21

• Manufacturer Part Number: cx29600
• Description: Optiphytm - M155 Sts-3 Sonet/sdh Multiplexer
• Manufacturer: Mindspeed Technologies

CX29600
CX29600 Data Sheet
29600-DSH-001-B
1.4 Terminology
The synchronous digital hierarchy (SDH) is the international counterpart to the
synchronous optical network (SONET) used in the United States, Canada, and
Japan. As such, SDH and SONET use different terminology to express similar
concepts.
Table 1-3. SONET/SDH Terminology
Payload Envelope
VT Synchronized
Virtual Tributary
Table 1-3
VTG1, VTG2
VT Payload
VT Group
SONET
SPE-1
SPE-3
(SPE)
VT1.5
VTG3
VT2
VT3
VT6
—
—
—
—
Mindspeed Technologies
compares SONET terminology with SDH terminology.
Virtual Container
Container (C-n)
Tributary Unit
TU Group
TUG-21
(VC-n)
VC-31
VC-32
TU-11
TU-12
TU-21
TU-22
TU-31
TU-32
SDH
VC-4
—
—
Usable payload, sized to carry a standard DS-n
261 column capacity.
VC (SPE) plus the pointers to locate the start of
(n = 1–4); the VC minus the column of path
overhead.
VT Payload or VC plus its column of path
overhead (POH).
or an assembly of TUG-2s or TU-3s.
Width of 65 columns fits 4 times (a TUG-31) into
a VC-4.
the VC/SPE, in a four-frame superframe.
1.544 Mbit/s (first form of DS-1) in 3 columns.
2.048 Mbit/s (second form of DS-1) in
4 columns.
For T1-c at 3.152 Mbit/s, not a CEPT rate, in
6 columns.
6.912 Mbit/s payload in 12 columns, 5 map to
1 VC-31.
9.216 Mbit/s payload in 16 columns, 4 map into
1 VC-31.
For E-3 in 65 columns.
For T-3 or STS-1 in 85 columns.
TUG-2 is an assembly of identical TU-1s or
TU-2s.
Contains 4 TU-11s (VTG1), 3 TU-12s (VTG2), or
1 TU-21 (VTG4) in 12 columns.
A group of two VC3s, not a defined CEPT rate.
85 column capacity.
™
n = 1, 2; basic VC of single C-n with n = 1 or 2.
n = 3, 4: higher order VC of one C-n (n = 3, 4),
Definition
1.0 Product Description
1.4 Terminology
1-7