Sdh Overhead Bytes 382l18
This document was ed by and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this report form. Report 3i3n4
Overview 26281t
& View Sdh Overhead Bytes as PDF for free.
More details 6y5l6z
- Words: 3,200
- Pages: 45
SDH Overhead Bytes
SDH Overhead Bytes
SDH Frame: Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
2. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
Regenerator Section Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
3. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
A1, A2 Framing A1
Provide a frame (F) alignment pattern A1 = 11110110 A2 = 00101000 Provided for each STM-1 signal within an STM-n
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
J0 Regenerator Section Trace A1
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
Transmits a fixed pattern repetitively Used by the section receiver to its continued connection to the intended transmitter
SDH Overhead Bytes
J0 Regenerator Section Trace The Trace (pattern) is an assigned string (either 16 or 64 bytes in length) with an included ending CRC byte The Trace is sent a byte per frame Both ends of a link set their own unique transmit values and compare the received values with the expected
Send : “…NE A send” Send : “Expect NE B…” Expect : “Expect NE B…” Expect : “…NE A send”
NE A
NE B
?
NE C
Send : “…NE B send” Send : “Expecting NE C…” Expect : “Expecting NE C…”Expect : “…NE B send” Receive : “…different message…” SDH Overhead Bytes
B1 8-bit Parity Check A1 B1
A1
A1
A2 E1
A2
A2
J0
J1
F1
B3
Provides an 8-bit wide bitD1 D2 D3 interleaved even parity check H1 H2 H3 B2 K1 K2 for error performance D4 D5 D6 monitoring at the D7 D8 D9 regenerator section level D10 D11 D12 The parity check is computed S1 Z1 Z2 M1 E2 for all bytes of the previous STM-N frame after scrambling The computed value is placed in this byte before scrambling Provided for the first STM-1 signal within an STM-N
C2 G1 F2 H4 F3 K3 N1
SDH Overhead Bytes
B1 8-bit Parity Checking Byte # 1 2 3 4 … 2429 2430 BIP(e)
Tx Value
Rx Value
76543210
76543210
01010110 01010110 10110110 (…Noise…) 11111111 10101010 10101010 … … … … 11001101 11001101 01100110 01100110 –––––––– –––––––– 11100001 Mismatch 10101000 –––––––– ––––––––
Changes across one byte can always be detected Double bit changes (2 “0”s going to 2 “1”s) down a bit column cannot always be detected Noise corruptions would affect several/many bytes SDH Overhead Bytes
E1, E2 Orderwire Channels A1
Provide a local orderwire channel for voice communication E1 is part of the RSOH and may be accessed at regenerators
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
9. 45
A1
Z1
Z2
M1 E2
E2 is part of the MSOH and may be accessed at Multiplex Section terminations
Provided for the first STM-1 signal within an STM-N
N1
SDH Overhead Bytes
F1 Channel A1
10. 45
Allocated for ’s purposes Terminated at all regenerator section-level equipment Provided for the first STM-1 signal within an STM-N
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
D1-D3, D4-D12 Datacom Channel (DCC)
Provide a message-based data communications channel, including istration, monitor, alarm and maintenance functions
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
11. 45
A1
Z1
Z2
M1 E2
N1
D1-D3 define a 192 Kbps channel in the RSOH
D4-D12 define a 576 Kbps channel in the MSOH
Provided for the first STM-1 signal within an STM-N SDH Overhead Bytes
AU Pointer Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
12. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
H1-H3 AU Pointers Provide indications and flags regarding the frame contents Define the start position of the VC-4 within the STM-1 frame
A1
13. 45
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A1
Z1
Z2
M1 E2
N1
Provide a method for letting the VC-4 “float” within the AU-4 frame Provide an indication of AU-4 concatenation SDH Overhead Bytes
H1-H3 Contents
In the STM-0 frame (a single VC-3) the relevant overhead bytes total 3 bytes NNNN S S I D I D I D I D I D Justification 1 2 3 4 5 6 7 8 9 10111213141516
H1
H2
H3
In the STM-1 frame (a VC-4 (i.e. three VC-3 frames), the same information bits are spread over 9 bytes with the infill bits preset Justification
NNNNXX I D 1 0 0 1 S S 1 1 1 0 0 1 S S 1 1 I D I D I D I D 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 123456781234567812345678123456781234567812345678
H1 14. 45
H1
H1
H2
H2
H2
H3
H3
H3
SDH Overhead Bytes
H1-H3 Contents 10-bit pointer value
N N N N S S I D I D I D I D I D Negative justification opportunity 1 2 3 4 5 6 7 8 9 10111213141516
H1 I D N
H2
= Increment = Decrement = New data flag (from 0110 to 1001)
Pointer value (b7-b16) : Normal range is 0-782 (for AU-4)
H3 Negative justification : Invert 5 D-bits, accept majority vote Positive justification : Invert 5 I-bits, accept majority vote
SS bits = 10 / AU-4,AU-3 structure 15. 45
SDH Overhead Bytes
Link Between Section Overhead and VC F
F Frame “N”
F
F
Frame “N+1”
Pointer Bytes Section Overhead Frame “N”
Pointer Bytes
J1
Virtual Container
Section Overhead Frame “N+1”
16. 45
SDH Overhead Bytes
AU-4 Pointer Adjustment: Positive Justification
1) Indicating the mismatch
17. 45
H1
H2
H3
2) Changing the I/D flag
H1
H2
H3
3) Pushing the VC-4 for 3 bytes span
H1
H2
4) Pointing to the new pointer value
H1
H2
H3
H3
1 2+3 4 SDH Overhead Bytes
AU-4 Pointer Adjustment: Negative Justification
1) Indicating the mismatch
H1
H2 H3
2) Changing the I/D flag
H1
H2 H3
3) Pulling the VC-4 for 3 bytes span
H1
H2
H1
H2 H3
4) Pointing to the new pointer value 18. 45
1 2+3 4 SDH Overhead Bytes
Multiplexer Section Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
19. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
B2 24-bit Parity Check A1 B1
20. 45
A1
A1
A2 E1
A2
A2
J0
J1
F1
B3
D1 D2 D3 C2 Include a 24-bit wide bitH1 H2 H3 G1 interleaved even parity B2 K1 K2 F2 check, for error D4 D5 D6 H4 D7 D8 D9 F3 performance monitoring D10 D11 D12 K3 at the multiplexer S1 Z1 Z2 M1 E2 N1 section level The check is computed for all bytes of the previous STM-N frame, except those located in the RSOH Provided for each STM-1 signal within an STM-N
SDH Overhead Bytes
B2 24-bit Parity Checking Byte # 1 4 7 10 … 2398 2401 BIP-24 (e)
76543210
76543210
76543210
01010110 10110110 10101010 … … 11001101 01100110 –––––––– 11100001 ––––––––
11001101 10011001 01100110
01010110 11111111 10101010 … … 11001101 01100110 –––––––– 10101000 ––––––––
11100111 00110010 –––––––– 11100111 ––––––––
Changes affecting adjacent across several bytes are more likely to be detected. Double bit changes (2 “0”s going to 2 “1”s) down a bit column cannot always be detected Noise corruptions would affect several/many bytes SDH Overhead Bytes
K1 Multiplexer Protection Switching (MPS) A1
Provides MPS signaling between multiplexer section terminating equipment Provided for the first STM-1 signal within an STM-N
22. 45
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
K2 Remote Defect Indication (RDI)
A1
Used to return an indication to the transmit end that the received end has detected an incoming section defect or is receiving AIS
23. 45
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A1
Z1
Z2
M1 E2
N1
Provided for the first STM-1 signal within an STM-N
SDH Overhead Bytes
S1 Quality of Synchronization A1
A1
A1
B1
Indicates the type of clock source used to time the transmitted signal The indications are one of the four synchronization levels agreed to by the ITU-T, or that the source should not be used D1
A2
J0
J1
E1
F1
B3
D2
D3
C2
H1 B2
A2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
24. 45
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
S1 Contents Code Stratum Synchronization level 1
0100
2
5 x 10-9 SSU-T (synch. source unit - transit)
1000
3
1 x 10-7 SSU-L (synch. source unit - local)
1011
4
1111 25. 45
1 x 10-11 PRC
0010
4.6 x 10-6 SEC DNU
(primary reference clock)
(SDH equipment clock) (do not use) SDH Overhead Bytes
M1 Remote Error Indication (REI) A1
A1
A2
A2
J0
J1
E1
F1
B3
D1
D2
D3
C2
Used to send error performance information from multiplexer section receiving equipment to the originating equipment Conveys the count of interleaved bit blocks detected in error by the B2 byte H1
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
26. 45
A2
B1
B2
A1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
Path Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
27. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
J1 Path Trace
Provides a unique message set up for each path in the SDH network s continuity testing between any location on a transmission path and the path source location Provided for each VC-4 frame in the frame A1
A1
A1
A2
28. 45
J0
J1
E1
F1
B3
D1
D2
D3
C2
B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A2
B1
H1
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
B3 8-bit Parity Check A1
A1
A1
A2
J1
F1
B3
D1
D2
D3
C2
Includes an 8-bit wide bit-interleaved parity check that provides error performance monitoring at the VC-4 level The parity check is computed for all bytes of the previous VC-4 before scrambling The computed value is placed in this byte before scrambling H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
29. 45
J0
E1
B2
A2
B1
H1
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
C2 Signal Label A1
Provides an indication of the payload construction by means of a value label assigned from a list of 11 possibilities
30. 45
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A1
Z1
Z2
M1 E2
N1
Indicates what type of payloads are mapped within the virtual container
SDH Overhead Bytes
C2 Content Standard binary values for C2 are :
31. 45
0000 0000 0000 0001 0000 0010 0000 0011 0000 0100 0001 0010 0001 0011 0001 0100 0001 0101 1111 1110 1111 1111
Unequipped Equipped, non-specific TUG structure Locked TU-n 34 Mbps or 45 Mbps into C-3 asynchronous 140 Mbps into C-4 asynchronous ATM mapping MAN (DQDB) mapping FDDI mapping Test signal, O.181 specific mapping VC-AIS SDH Overhead Bytes
G1 Path Status A1
32. 45
Sends status and performance monitoring information from the receiving terminating equipment to the originating equipment
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
Bits 1-4 convey the count of errors detected by B3 Bit 5 indicates a path Remote Defect Indication (RDI) SDH Overhead Bytes
F2, F3 Channel A1
Allocated for network operator communication between path terminations
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
33. 45
A1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
H4 Multi-frame
Identifies which frame of the multi-frame is present in the current VC-4
A1
A1
34. 45
(The TU overhead is distributed over four TU frames comprising the TU multi-frame)
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
A1
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
TU-1/2 Multiframe Indication: Example Using H4
V4
Example of TU-1/2 Multiframe Indication Using H4 Byte
VC-3 / VC-4 Payload
H4 (00)
V1
VC-3 / VC-4 Payload
H4 (01)
V2
VC-3 / VC-4 Payload
H4 (10)
V3
VC-3 / VC-4 Payload
H4 (11)
V4 H4 (00)
35. 45
VC-3 / VC-4 Payload
SDH Overhead Bytes
K3 Automatic Protection Switch (APS)
Used to provide path-level protection switching on individual VC-4 paths A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
36. 45
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
N1 Tandem Connection (TC) Monitor A1
A1
A1
A2
J1
F1
B3
D1
D2
D3
C2
s end-to-end performance monitoring of a tandem connection (path sub-section) Communicates the number of B3 errors Bits 1-4 serve as incoming error count; Bit 5 serves as a TC-REI Bit 6 serves as an outgoing error indication Bits 7-8 serve as a multiframe (TC-APID, TC-RDI, ODI, reserved) H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
37. 45
J0
E1
B2
A2
B1
H1
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
TU-1/2 Pointers and VC-1/2 Path Overhead V1
V5
V2
125 µs
V3
250 µs
N2
V4
375 µs
K4
J2
500 µs
38. 45
SDH Overhead Bytes
V5 Error Checking, Signal Label, Path Status
39. 45
V5 Bits 1-2 are used for a Bit Interleaved Parity (BIP) check on the previous VC-2/VC-1 J2 Bit 3 is a path Remote Error Indicator (REI) N2 Bit 4 is a path Remote Failure Indicator (RFI) K4 Bits 5-7 provide a VC-2/VC-1 signal label Bit 8 is a path Remote Defect Indicator (RDI)
SDH Overhead Bytes
V5 Detail BIP-2
REI
RFI
3
4
Signal
RDI
V5 functions :
1
2
5
6
7
8
Signal Labels : 0 0 0 Unequipped or supervisory-unequipped 0 0 1 Equipped – non-specific 0 1 0 Asynchronous 0 1 1 Bit synchronous 1 0 0 Byte synchronous 1 0 1 Reserved for future use 1 1 0 Test signal, O.181 specific mapping 1 1 1 VC-AIS
40. 45
SDH Overhead Bytes
J2 Path Trace
Used to transmit repetitively a Low Order Path Access Point Identifier, so that a path receiving terminal can its continued connection to the intended transmitter Used in the same way as J0 in the SOH
V5
J2
N2
K4
41. 45
SDH Overhead Bytes
N2 Tandem Connection (TC)
42. 45
Bits 1-2 are used as an even BIP-2 check for the Tandem Connection Bit 4 operates as an incoming AIS indicator Bit 5 indicates errored blocks within the TC Bit 6 indicates errored blocks of the ingressing VC-n Bits 7-8 operate in multi-frame as an access point identifier and as defect indicators
V5
J2
N2
K4
SDH Overhead Bytes
K4 Automatic Protection Switching (APS)
Bits 1-4 are allocated for APS signaling for protection at the lower order path level V5
J2
N2
K4
43. 45
SDH Overhead Bytes
SDH Basics STM-1 : 270 columns x 9 rows
RSOH
J1 F i P xS O e T H dU F F
AU-3/AU-4 Pointer MSOH
N P I
TUG-3 POINTER
VC-4 : 261 columns
TU-3 .Ptr
TU-3 .Ptr
V C 3 P O H
*TU-3 : 86 columns
X3* C3=34/45 Mbit/s
* TUG-3 : 86 columns
FIXED STUFF
TU-2 .Ptr VC-2 POH
X7*
C2=6 Mbit/s TU- 2 : 12 columns*
TU-2 Ptr.
*TUG-2 :12 columns
TU-12 Ptr. VC-12 POH
44. 45
TU-12 : 4 columns
Pointer resolution Fixed position * Byte interleave SDH Overhead Bytes
ETSI SDH Multiplexing Scheme
Synchronous port HPX STM-1
Plesinchronous port
AU-4 Assembler VC-4
C-4
140 Mbps
VC-3
C-3
34 Mbps
VC-12
C-12
2 Mbps
LPX
TUG-3
TU-3
TUG-2
TU-2
TU-12
45. 45
VC-4
SDH Overhead Bytes
SDH Overhead Bytes
SDH Frame: Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
2. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
Regenerator Section Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
3. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
A1, A2 Framing A1
Provide a frame (F) alignment pattern A1 = 11110110 A2 = 00101000 Provided for each STM-1 signal within an STM-n
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
J0 Regenerator Section Trace A1
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
Transmits a fixed pattern repetitively Used by the section receiver to its continued connection to the intended transmitter
SDH Overhead Bytes
J0 Regenerator Section Trace The Trace (pattern) is an assigned string (either 16 or 64 bytes in length) with an included ending CRC byte The Trace is sent a byte per frame Both ends of a link set their own unique transmit values and compare the received values with the expected
Send : “…NE A send” Send : “Expect NE B…” Expect : “Expect NE B…” Expect : “…NE A send”
NE A
NE B
?
NE C
Send : “…NE B send” Send : “Expecting NE C…” Expect : “Expecting NE C…”Expect : “…NE B send” Receive : “…different message…” SDH Overhead Bytes
B1 8-bit Parity Check A1 B1
A1
A1
A2 E1
A2
A2
J0
J1
F1
B3
Provides an 8-bit wide bitD1 D2 D3 interleaved even parity check H1 H2 H3 B2 K1 K2 for error performance D4 D5 D6 monitoring at the D7 D8 D9 regenerator section level D10 D11 D12 The parity check is computed S1 Z1 Z2 M1 E2 for all bytes of the previous STM-N frame after scrambling The computed value is placed in this byte before scrambling Provided for the first STM-1 signal within an STM-N
C2 G1 F2 H4 F3 K3 N1
SDH Overhead Bytes
B1 8-bit Parity Checking Byte # 1 2 3 4 … 2429 2430 BIP(e)
Tx Value
Rx Value
76543210
76543210
01010110 01010110 10110110 (…Noise…) 11111111 10101010 10101010 … … … … 11001101 11001101 01100110 01100110 –––––––– –––––––– 11100001 Mismatch 10101000 –––––––– ––––––––
Changes across one byte can always be detected Double bit changes (2 “0”s going to 2 “1”s) down a bit column cannot always be detected Noise corruptions would affect several/many bytes SDH Overhead Bytes
E1, E2 Orderwire Channels A1
Provide a local orderwire channel for voice communication E1 is part of the RSOH and may be accessed at regenerators
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
9. 45
A1
Z1
Z2
M1 E2
E2 is part of the MSOH and may be accessed at Multiplex Section terminations
Provided for the first STM-1 signal within an STM-N
N1
SDH Overhead Bytes
F1 Channel A1
10. 45
Allocated for ’s purposes Terminated at all regenerator section-level equipment Provided for the first STM-1 signal within an STM-N
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
D1-D3, D4-D12 Datacom Channel (DCC)
Provide a message-based data communications channel, including istration, monitor, alarm and maintenance functions
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
11. 45
A1
Z1
Z2
M1 E2
N1
D1-D3 define a 192 Kbps channel in the RSOH
D4-D12 define a 576 Kbps channel in the MSOH
Provided for the first STM-1 signal within an STM-N SDH Overhead Bytes
AU Pointer Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
12. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
H1-H3 AU Pointers Provide indications and flags regarding the frame contents Define the start position of the VC-4 within the STM-1 frame
A1
13. 45
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A1
Z1
Z2
M1 E2
N1
Provide a method for letting the VC-4 “float” within the AU-4 frame Provide an indication of AU-4 concatenation SDH Overhead Bytes
H1-H3 Contents
In the STM-0 frame (a single VC-3) the relevant overhead bytes total 3 bytes NNNN S S I D I D I D I D I D Justification 1 2 3 4 5 6 7 8 9 10111213141516
H1
H2
H3
In the STM-1 frame (a VC-4 (i.e. three VC-3 frames), the same information bits are spread over 9 bytes with the infill bits preset Justification
NNNNXX I D 1 0 0 1 S S 1 1 1 0 0 1 S S 1 1 I D I D I D I D 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 123456781234567812345678123456781234567812345678
H1 14. 45
H1
H1
H2
H2
H2
H3
H3
H3
SDH Overhead Bytes
H1-H3 Contents 10-bit pointer value
N N N N S S I D I D I D I D I D Negative justification opportunity 1 2 3 4 5 6 7 8 9 10111213141516
H1 I D N
H2
= Increment = Decrement = New data flag (from 0110 to 1001)
Pointer value (b7-b16) : Normal range is 0-782 (for AU-4)
H3 Negative justification : Invert 5 D-bits, accept majority vote Positive justification : Invert 5 I-bits, accept majority vote
SS bits = 10 / AU-4,AU-3 structure 15. 45
SDH Overhead Bytes
Link Between Section Overhead and VC F
F Frame “N”
F
F
Frame “N+1”
Pointer Bytes Section Overhead Frame “N”
Pointer Bytes
J1
Virtual Container
Section Overhead Frame “N+1”
16. 45
SDH Overhead Bytes
AU-4 Pointer Adjustment: Positive Justification
1) Indicating the mismatch
17. 45
H1
H2
H3
2) Changing the I/D flag
H1
H2
H3
3) Pushing the VC-4 for 3 bytes span
H1
H2
4) Pointing to the new pointer value
H1
H2
H3
H3
1 2+3 4 SDH Overhead Bytes
AU-4 Pointer Adjustment: Negative Justification
1) Indicating the mismatch
H1
H2 H3
2) Changing the I/D flag
H1
H2 H3
3) Pulling the VC-4 for 3 bytes span
H1
H2
H1
H2 H3
4) Pointing to the new pointer value 18. 45
1 2+3 4 SDH Overhead Bytes
Multiplexer Section Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
19. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
B2 24-bit Parity Check A1 B1
20. 45
A1
A1
A2 E1
A2
A2
J0
J1
F1
B3
D1 D2 D3 C2 Include a 24-bit wide bitH1 H2 H3 G1 interleaved even parity B2 K1 K2 F2 check, for error D4 D5 D6 H4 D7 D8 D9 F3 performance monitoring D10 D11 D12 K3 at the multiplexer S1 Z1 Z2 M1 E2 N1 section level The check is computed for all bytes of the previous STM-N frame, except those located in the RSOH Provided for each STM-1 signal within an STM-N
SDH Overhead Bytes
B2 24-bit Parity Checking Byte # 1 4 7 10 … 2398 2401 BIP-24 (e)
76543210
76543210
76543210
01010110 10110110 10101010 … … 11001101 01100110 –––––––– 11100001 ––––––––
11001101 10011001 01100110
01010110 11111111 10101010 … … 11001101 01100110 –––––––– 10101000 ––––––––
11100111 00110010 –––––––– 11100111 ––––––––
Changes affecting adjacent across several bytes are more likely to be detected. Double bit changes (2 “0”s going to 2 “1”s) down a bit column cannot always be detected Noise corruptions would affect several/many bytes SDH Overhead Bytes
K1 Multiplexer Protection Switching (MPS) A1
Provides MPS signaling between multiplexer section terminating equipment Provided for the first STM-1 signal within an STM-N
22. 45
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
K2 Remote Defect Indication (RDI)
A1
Used to return an indication to the transmit end that the received end has detected an incoming section defect or is receiving AIS
23. 45
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A1
Z1
Z2
M1 E2
N1
Provided for the first STM-1 signal within an STM-N
SDH Overhead Bytes
S1 Quality of Synchronization A1
A1
A1
B1
Indicates the type of clock source used to time the transmitted signal The indications are one of the four synchronization levels agreed to by the ITU-T, or that the source should not be used D1
A2
J0
J1
E1
F1
B3
D2
D3
C2
H1 B2
A2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
24. 45
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
S1 Contents Code Stratum Synchronization level 1
0100
2
5 x 10-9 SSU-T (synch. source unit - transit)
1000
3
1 x 10-7 SSU-L (synch. source unit - local)
1011
4
1111 25. 45
1 x 10-11 PRC
0010
4.6 x 10-6 SEC DNU
(primary reference clock)
(SDH equipment clock) (do not use) SDH Overhead Bytes
M1 Remote Error Indication (REI) A1
A1
A2
A2
J0
J1
E1
F1
B3
D1
D2
D3
C2
Used to send error performance information from multiplexer section receiving equipment to the originating equipment Conveys the count of interleaved bit blocks detected in error by the B2 byte H1
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
26. 45
A2
B1
B2
A1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
Path Overhead Bytes
A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1
H2
B2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
E2
N1
S1
27. 45
A2
Z1
Z2
M1
SDH Overhead Bytes
J1 Path Trace
Provides a unique message set up for each path in the SDH network s continuity testing between any location on a transmission path and the path source location Provided for each VC-4 frame in the frame A1
A1
A1
A2
28. 45
J0
J1
E1
F1
B3
D1
D2
D3
C2
B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A2
B1
H1
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
B3 8-bit Parity Check A1
A1
A1
A2
J1
F1
B3
D1
D2
D3
C2
Includes an 8-bit wide bit-interleaved parity check that provides error performance monitoring at the VC-4 level The parity check is computed for all bytes of the previous VC-4 before scrambling The computed value is placed in this byte before scrambling H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
29. 45
J0
E1
B2
A2
B1
H1
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
C2 Signal Label A1
Provides an indication of the payload construction by means of a value label assigned from a list of 11 possibilities
30. 45
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
A1
Z1
Z2
M1 E2
N1
Indicates what type of payloads are mapped within the virtual container
SDH Overhead Bytes
C2 Content Standard binary values for C2 are :
31. 45
0000 0000 0000 0001 0000 0010 0000 0011 0000 0100 0001 0010 0001 0011 0001 0100 0001 0101 1111 1110 1111 1111
Unequipped Equipped, non-specific TUG structure Locked TU-n 34 Mbps or 45 Mbps into C-3 asynchronous 140 Mbps into C-4 asynchronous ATM mapping MAN (DQDB) mapping FDDI mapping Test signal, O.181 specific mapping VC-AIS SDH Overhead Bytes
G1 Path Status A1
32. 45
Sends status and performance monitoring information from the receiving terminating equipment to the originating equipment
A1
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
Bits 1-4 convey the count of errors detected by B3 Bit 5 indicates a path Remote Defect Indication (RDI) SDH Overhead Bytes
F2, F3 Channel A1
Allocated for network operator communication between path terminations
A1
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
33. 45
A1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
H4 Multi-frame
Identifies which frame of the multi-frame is present in the current VC-4
A1
A1
34. 45
(The TU overhead is distributed over four TU frames comprising the TU multi-frame)
A2
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
A1
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
TU-1/2 Multiframe Indication: Example Using H4
V4
Example of TU-1/2 Multiframe Indication Using H4 Byte
VC-3 / VC-4 Payload
H4 (00)
V1
VC-3 / VC-4 Payload
H4 (01)
V2
VC-3 / VC-4 Payload
H4 (10)
V3
VC-3 / VC-4 Payload
H4 (11)
V4 H4 (00)
35. 45
VC-3 / VC-4 Payload
SDH Overhead Bytes
K3 Automatic Protection Switch (APS)
Used to provide path-level protection switching on individual VC-4 paths A1
A1
A1
A2
A2
J0
J1
B1
E1
F1
B3
D1
D2
D3
C2
H1 B2
H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
36. 45
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
N1 Tandem Connection (TC) Monitor A1
A1
A1
A2
J1
F1
B3
D1
D2
D3
C2
s end-to-end performance monitoring of a tandem connection (path sub-section) Communicates the number of B3 errors Bits 1-4 serve as incoming error count; Bit 5 serves as a TC-REI Bit 6 serves as an outgoing error indication Bits 7-8 serve as a multiframe (TC-APID, TC-RDI, ODI, reserved) H2
H3
G1
K1
K2
F2
D4
D5
D6
H4
D7
D8
D9
F3
D10
D11
D12
K3
S1
37. 45
J0
E1
B2
A2
B1
H1
A2
Z1
Z2
M1 E2
N1
SDH Overhead Bytes
TU-1/2 Pointers and VC-1/2 Path Overhead V1
V5
V2
125 µs
V3
250 µs
N2
V4
375 µs
K4
J2
500 µs
38. 45
SDH Overhead Bytes
V5 Error Checking, Signal Label, Path Status
39. 45
V5 Bits 1-2 are used for a Bit Interleaved Parity (BIP) check on the previous VC-2/VC-1 J2 Bit 3 is a path Remote Error Indicator (REI) N2 Bit 4 is a path Remote Failure Indicator (RFI) K4 Bits 5-7 provide a VC-2/VC-1 signal label Bit 8 is a path Remote Defect Indicator (RDI)
SDH Overhead Bytes
V5 Detail BIP-2
REI
RFI
3
4
Signal
RDI
V5 functions :
1
2
5
6
7
8
Signal Labels : 0 0 0 Unequipped or supervisory-unequipped 0 0 1 Equipped – non-specific 0 1 0 Asynchronous 0 1 1 Bit synchronous 1 0 0 Byte synchronous 1 0 1 Reserved for future use 1 1 0 Test signal, O.181 specific mapping 1 1 1 VC-AIS
40. 45
SDH Overhead Bytes
J2 Path Trace
Used to transmit repetitively a Low Order Path Access Point Identifier, so that a path receiving terminal can its continued connection to the intended transmitter Used in the same way as J0 in the SOH
V5
J2
N2
K4
41. 45
SDH Overhead Bytes
N2 Tandem Connection (TC)
42. 45
Bits 1-2 are used as an even BIP-2 check for the Tandem Connection Bit 4 operates as an incoming AIS indicator Bit 5 indicates errored blocks within the TC Bit 6 indicates errored blocks of the ingressing VC-n Bits 7-8 operate in multi-frame as an access point identifier and as defect indicators
V5
J2
N2
K4
SDH Overhead Bytes
K4 Automatic Protection Switching (APS)
Bits 1-4 are allocated for APS signaling for protection at the lower order path level V5
J2
N2
K4
43. 45
SDH Overhead Bytes
SDH Basics STM-1 : 270 columns x 9 rows
RSOH
J1 F i P xS O e T H dU F F
AU-3/AU-4 Pointer MSOH
N P I
TUG-3 POINTER
VC-4 : 261 columns
TU-3 .Ptr
TU-3 .Ptr
V C 3 P O H
*TU-3 : 86 columns
X3* C3=34/45 Mbit/s
* TUG-3 : 86 columns
FIXED STUFF
TU-2 .Ptr VC-2 POH
X7*
C2=6 Mbit/s TU- 2 : 12 columns*
TU-2 Ptr.
*TUG-2 :12 columns
TU-12 Ptr. VC-12 POH
44. 45
TU-12 : 4 columns
Pointer resolution Fixed position * Byte interleave SDH Overhead Bytes
ETSI SDH Multiplexing Scheme
Synchronous port HPX STM-1
Plesinchronous port
AU-4 Assembler VC-4
C-4
140 Mbps
VC-3
C-3
34 Mbps
VC-12
C-12
2 Mbps
LPX
TUG-3
TU-3
TUG-2
TU-2
TU-12
45. 45
VC-4
SDH Overhead Bytes
Related Documents 3h463d
Sdh Overhead Bytes 382l18
October 2019 29
Sdh 3o1d
March 2023 0
Mal Bytes 1z2w4r
July 2021 0
Ordenamiento De Bytes 3k2n25
December 2019 95
Sdh Protection 253e26
November 2019 49