Figure 4-15
VC-3-Xv/VC4-Xv multiframe and sequence indicator
C-3-X/C-4-X
1
X
C-3-Xv/C-4-Xv
P
O
H
P
O
H
M
u
lti
fr
a
m
e
(
M
F
)
SQ = 0
MFI-1 = 0
MFI-2 = 0
SQ = 0
MFI-1 = 1
MFI-2 = 0
P
O
H
P
O
H
SQ = 0
MFI-1 = 15
MFI-2 = 255
SQ = 0
MFI-1 = 0
MFI-2 = 0
P
O
H
P
O
H
SQ = 0
MFI-1 = 15
MFI-2 = 0
SQ = 0
MFI-1 = 0
MFI-2 = 1
H
H
H
SQ = X-1
SQ = X-1
SQ = X-1
= 1
= 0
= 0
= 0
X-1
= 15
= 0
= 0
= 15
X-1
= 15
= 255
= 0
= 0
X-1
With the MFI and SQ, the sink end can correctly restore the position of each frame in the C-n-
Xv to prevent the frame alignment problem due to the different propagation delays of the frames.
VC-12-Xv
The virtual container that is formed by a VC-12-Xv can be mapped into X individual VC-12s
which form the VC-12-Xv. Each VC-12 has its own POH. POH has the same specifications as
the ordinary VC-12 POH. Bit 2 of the K4 byte in the POH is used for the virtual concatenation-
specific frame count and sequence indicator.
Bit2s of the K4 bytes in every 32 multiframes (one multiframe comprising four VC-12s) are
extracted to form a 32-bit character string to express the frame count and sequence indicator.
Bits 1-5 of the string express the frame count, whose value range is between 0 and 31. structure
formed by 32 multiframes has 128 frames. Hence, the resulting overall multiframe is 4096 frames
with the period of 512 ms. Bits 6-11 of the string express the sequence indicator. The frame
count/sequence indicator in the VC-12-Xv has the same usage as the multiframe indicator/
sequence indicator in the VC4-Xv/VC-3-Xv.
4.2.7 Tag Attribute
When data frames are received on or transmitted from a port on an Ethernet board, the processing
mode of the data frames is determined by the tag attributes of the port.
The tags for the port on an Ethernet board are available in three types: tag aware, access, and
hybrid.
OptiX OSN 550 Multi-Service CPE Optical Transmission
System
Configuration Guide
4 Configuring Ethernet Services
Issue 02 (2011-06-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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