Difference between sdh and sonet by helvoort

SDH & SONET – commonalities and differences 1 of 6 14/01/04
Huub van Helvoort Version 0.1
Overview of SDH and SONET overhead processing commonalities and differences.
The SDH information is based on ITU-T G.707, G.783 and ETSI EN 300 417-x-1 (x=1..7,9)
The SONET information is based on ANSI T1.105, T1.231 and Telcordia GR253
If you find errors or have additional information or remarks, please notify me: hhelvoort@chello.nl
A Adaptation function PDI Payload Defect Indicator
AIS Alarm Indication Signal PLM PayLoad Mismatch
AISS AIS Seconds PM Performance Monitoring
APS Automatic Protection Switch PPJC Positive Pointer Justification Counter
AU Administrative Unit PT Path Termination function
BIP Bit Interleaved parity RDI Remote Defect Indication
C Connection function RDIc Remote connectivity Defect Indication
DEG Degraded RDIp Remote payload Defect Indication
ERDI Enhanced RDI RDIs Remote server Defect Indication
EXC Excessive REI Remote Error Indication
F_EBC Far end Errored Block Count RFI Remote Failure Indication
F_DS Far end Defect Second SD Signal Degrade
FOP Failure Of Protocol SEFS Severely Errored Frame Second
LOF Loss Of Frame SF Signal fail
LOP Loss Of Pointer SPE Synchronous Payload Envelope
LOPS LOP Seconds STS Synchronous Transport Signal
N_EBC Near end Errored Block Count TIM Trace identifier Mismatch
N_DS Near end Defect Second TU Tributary Unit
NDF New Data Flag UNEQ Unequipped
NIM Non Intrusive Monitor function VC Virtual Container
NPJC Negative Pointer Justification Counter VCAT Virtual conCATenation
OFS Out of Frame Second VT Virtual Tributary
PJE+ positive Pointer Justification Event
PJE- negative Pointer Justification Event
SDH SONET
Regenerator Section SectionOH byte Direction Process Location
RS-0/1/4/16/64/256 STS-1/3/12/48/192/768
Source insertion y y
defect - LOF OOF: 5 frames
LOF: 3 ms with filtering
OOF: 4 frames
LOF: 3 ms
PM (OFS [SEFS]) n y
PM – N_DS y y
consequent action - AIS y y
consequent action - RDI y y
A1A2 - frame alignment
signal
Sink
protection switching - SF y y
Source calculation y y
defect – DEG (in regenerator applications) y n
PM – N_EBC n, under study in G.829 y, based on BIP8 violations
Protection Switching - SF n n
B1 - BIP8
Sink
Protection Switching - SD n n
Source insertion #1..#N #1..#3N
C1 - … OBSOLETE
Sink ignored y y
Source
insertion 16 byte string 1 byte string
(64 byte string is under study)
defect - TIM y n
PM – N_DS y n
consequent action - AIS y n
consequent action - RDI n/a n/a
protection switching - SF n/a n/a
J0 - section trace
identifier
Sink
acceptance & reporting y y
Source insertion -fixed stuff (N-1) Z0 bytes (3N-1) Z0 bytes
Z0 - growth
Sink ignore y y
Source insertion - external y y (but not used)
E1 - Order Wire
Sink extract y y (but not used)
Source insertion - internal or external y n
F1 - user channel
Sink extract y n
D1-D3 - RS DCC
Sink extract y y
NU - national use Source insertion - fixed stuff or external y fixed stuff

Sink ignore y y
Source insertion - fixed stuff: all-0's y y
unmarked
Sink ignore y y
SDH SONET
Multiplex Section LineOH byte Direction Process Location
MS-0/1/4/16/64/256 STS-1/3/12/48/192/768
Source calculation y y
defect – EXC/DEG or DEG dDEG based on 1 second PM
info
dEXC/dDEG based on 10
-x
algorithm
PM – N_EBC y y
Protection Switching - SF y n
B2 - BIP24N
(defect and PM based on
BIP24N violations)
Sink
Protection Switching - SD y y
Source insertion - external
E2 - Order Wire
Sink extract
D4-D12 - MS DCC
Sink extract y y
Source
insertion K2[6-8] not used K2[6-8] used for switching type
indication
extraction K2[6-8] not used K2[6-8] used for switching type
indication
K1[1-8] K2[1-5(8)]
linear APS
Sink
defect - FOP y y
extraction y y
K1[1-8] K2[1-8]
ring APS Sink
defect -FOP y y
Source insertion min 1 frame min 20 frames
defect – RDI y yK2[6-8] – RDI [RDI-L]
Sink
PM – F_DS y y
Source -
defect -AIS y y
PM – N_DS y y
consequent action - AIS y y
consequent action - RDI y y
K2[6-8] - MS-AIS
Sink
protection switching - SF y y
Source
insert BIP violation number MS-0: n/a
MS-1/4/16/64/256: y
STS-1: n/a
STS-3/12/48/192/768: y
M1 - REI [REI-L]
(PM based on BIP24N
violations) Sink
PM – F_EBC MS-0: n/a
MS-1/4/16/64/256: y
STS-1: n/a
STS-3/12/48/192/768: y
Source insertion - fixed stuff or external y fixed stuff (all-0’s)
NU - national use
Sink ignore y y
Source insertion SDH code set SONET code set
extract SDH code set SONET code set
S1 - synchronisation
status message Sink
consequent action - …..
Source insertion - fixed stuff: all-0's n.a. y
Z1, Z2 - growth
Sink ignore n.a. y
Source insertion - fixed stuff: all-0's y y
unmarked
Sink ignore y y
SDH SONET
Administrative UnitOH byte Direction Process Location
AU-3/4/4-4c/4-16c/4-64c STS-1/3c/12c/48c/192c
pointer generation A ss = 10 ss = 10 (old ss = 00)
consequent action - AIS A 250 s 125 s
increment action A y y
decrement action A y y
new pointer action A y y
non-gapped pointer adjustments A y y
enhanced wander performance (dithering
method to reduce wander)
A n n
PM – PJE+, PJE- A y n
Source
PM – PPJC-Gen, NPJC-Gen, PJCS-Gen,
PJCDiff
A n y
SS-bits A ignore ignore
pointer interpretation A y (see Note) y (see Note)
increment detection A majority of D bits majority of D bits, or 8 out of 10
decrement detection A majority of I bits majority of I bits, or 8 out of 10
NDF enabled detection A y y
H1H2 – AU [STS] and
TU-3 pointer
Sink
defect - AIS A y y

defect - LOP A y y
PM – PPJC-Det, NPJC-Det, PJCS-Det A n y
PM – N_DS PT y y
consequent action - AIS (on defect) A 250 s 125 s
consequent action - AIS (on AIS
indication)
A n y
consequent action - RDI PT y y
consequent action - ERDI-server PT n y
protection switching - SF A y y
H1H2 – AU [STS]
pointer
Sink
AU [STS] multiplex structure determination A MS SPring
limited to the AU’s being part
of the protection capacity in a
MS SPRING ring that are not
deselected (locked out).
Other AU’s may only change
type on provisioning.
BLSR, STS pipe
Automatic mode default, Fixed
mode selectable per STS3
group.
insertion - data during justification action A y y
Source
insertion - fixed stuff otherwise A y y
extract – data during justification action A y y
H3 – AU [STS]
justification opportunity
Sink
ignore - otherwise A y y
Note - SONET pointer processing is defined by Telcordia where the standard T1.105 is unclear, i.e.:
1. Pass all 1's H1/H2 byte downstream immediately without waiting for AIS declaration which occurs after 3 frames.
2. Declare LOP condition if no 3 consecutive normal or no 3 consecutive AIS H1/H2 bytes are received in an 8 frame window (e.g. alternating AIS/normal pointer
will result in LOP).
3. Use 8 out of 10 criteria instead of majority vote for increment/decrement decision (Objective).
SDH SONET
Path Path
OH byte Direction Process Location
VC-3/4/4-Xc
(X=4,16,64,256)
STS-1/3c/12c/48c/192c
SPE
Source calculation PT y y
defect EXC./DEG or DEG
PT dDEG based on 1 second PM
info
-x
algorithm
PM – N_EBC
PT count errored blocks count BIP violations
(count errored blocks if ERDI
supported)
Protection Switching - SF NIM n y
PT y n/a
B3 - BIP8
Sink
Protection Switching - SD
NIM y y
Source insertion – all-0’s C y y
PT
defect -UNEQ NIM
y, ETSI specification requires
extra robustness for bursts of
errors
y
PT y n
PM – N_DS
NIM y n
consequent action - AIS PT y ?
consequent action - RDI PT y n
consequent action - ERDI-connectivity PT n y
PT y n/a
C2 - UNEQ
Sink
protection switching - SF
NIM y y
Source creation
PT n n
defect – AIS
NIM y n
PT n n
PM – N_DS
NIM y n
consequent action - AIS PT n n
consequent action - RDI PT n n
consequent action - ERDI-server PT n n
PT n n
C2 - VC-AIS
Sink
NIM y n
Source insertion A y y
A y (under study) y
defect – PLM
NIM n y
consequent action - AIS A y y
consequent action - RDI A n n
consequent action - ERDI-payload A n y
A y y
NIM n n
A y y
C2 - payload type
Sink
acceptance & reporting
NIM n y

Source
insertion - number of VT's within STS1 in
signal fail
A/PT n y
defect – PDI NIM n y
protection switching - SF NIM n y
C2 - Payload Defect
Indicator
Sink
acceptance & reporting n y
Source insertion - internal or external A y y
F2 - user channel
Sink ignore or extract A y y
Source undefined – fixed stuff insertion A y n/a
F3 - user channel (SDH)
Sink ignored A y n/a
Source undefined – fixed stuff insertion A n/a y
Z3 – growth (SONET)
Sink ignored A n/a y
Source insertion PT min 1 frame min 20 frames
PT
defect - RDI
NIM
5 frames 10 frames
PT y y
G1[5] – RDI [RDI-P]
Sink
PM – F_DS
NIM y y
Source insertion of BIP violation number PT y y
PTG1[1-4] - REI [REI-P]
Sink PM – F_EBC NIM
count errored blocks count BIP violations
supported)
A n y
Source insertion
PT n y
A n y
PT n ydefects - RDIs, RDIc, RDIp
NIM n y
PT n y
G1[5-7] - ERDI
Sink PM (RDIs, RDIc) – F_DS – T1.231 does
specify its use for PM, but this is not realy
needed; the use of RDI will be sufficient.
RDI = RDIs + RDIc
NIM n y
Source insertion – fixed stuff “0” y y
G1[8] - reserved
Sink ignore y y
Source insertion – fixed stuff / VCAT overhead A y y
H4[1-8]
Sink Ignore A y y
Source insertion – fixed stuff “111111” A y yH4[1-6] – TU multiframe
alignment signal Sink ignore A y y
defect – LOM for TU1/2 [VT] A y y
consequent action - AIS for TU1/2 [VT] A y y
H4[7-8] – TU multiframe
alignment signal Sink
protection switching - SF for TU1/2 [VT] A y y
insertion PT 16 byte string 64 byte string
Source
insertion – unequipped (all-0’s) C y y
PT y y
defect -TIM
NIM y n
fault cause – UNEQ (all zeroes detection) PT
PT y n (ERDI: y)
PM – N_DS
NIM y n (ERDI: y)
consequent action - AIS PT y n ?
consequent action - RDI PT y n ?
PT y n/a
NIM y n
PT y y
J1 - path trace identifier
Sink
NIM y y
Source insertionK3[1-4]- linear APS
(under study) Sink extraction
Source insertion
K3[5-6] - reserved
Sink ignore
Source insertionK3[7-8] – 16 kbit/s path
data link (details are
under study)
Sink extraction
Source insertion N/a fixed stuff
Z4 (SONET)
Sink ignore N/a y
SDH SONET
Path PathOH byte Direction Process Location
VC-2/12/11 VT-6/2/1.5
insertion PT 16 byte string 16 byte string
Source
insertion – unequipped (all-0’s) C y y
PT y n
J2 - path trace identifier
Sink
defect -TIM
NIM y n

fault cause – UNEQ (all zeroes detection) PT
PT y n (ERDI: y)
PM – N_DS
NIM y n (ERDI: y)
consequent action - AIS PT y n ?check T1.231, GR253?
consequent action - RDI PT y n ?check?
PT y n/a
NIM y n
PT y y
NIM y y
Source Insertion y yK4[1] – extended signal
label Sink extraction y y
Source Insertion y y
K4[2] – VCAT overhead
Sink extraction y y
Source insertion n/aK4[1-4] – linear APS
(under study) Sink extraction n/a
Source insertion – fixed stuff (“000” or “111”) n n/a
K4[5-7] – Reserved
Sink ignored n n/a
Source insertion n/aK4[8] – 2 kbit/s path
data link (under study) Sink extraction n/a
pointer generation A y y
consequent action - AIS A 1000 s 500 s
increment action A y y
decrement action A y y
new pointer action A y y
non-gapped pointer adjustments A y y
enhanced wander performance (dithering
method to reduce wander)
A n n
PM – PJE+, PJE- A n n
Source
PM – PPJC-Gen, NPJC-Gen, PJCS-Gen,
PJCDiff
A n y
pointer interpretation A y (note) y (note)
increment detection A majority of D bits majority of D bits, or 8 out of 10
decrement detection A majority of I bits majority of I bits, or 8 out of 10
NDF enabled detection A y y
defect – AIS A y y
defect – LOP A y y
PM – PPJC-Det, NPJC-Det, PJCS-Det A n y
PT y y
PM – N_DS
NIM y y
consequent action - AIS (on defect) A 1000 s 500 s
consequent action - AIS (on AIS
indication)
A n y
consequent action – RDI PT y y
consequent action - ERDI-server PT n y
V1V2 – TU [VT] pointer
Sink
protection switching – SF A y y
Note - Although pointer processing differences between the SONET and SDH standards may be hard to find, Bellcore does impose additional requirements where
the standard is unclear. SONET is supposed to also meet the additional Bellcore requirements, i.e.
1. Pass all 1's H1/H2 byte downstream immediately without waiting for AIS declaration which occurs after 3 frames.
2. Declare LOP condition if no 3 consecutive normal or no 3 consecutive AIS H1/H2 bytes are received in an 8 frame window (e.g. alternating AIS/normal pointer
will result in LOP).
3. Use 8 out of 10 criteria instead of majority vote for increment/decrement decision (Objective).
insertion - data during justification action A y y
Source
insertion - fixed stuff otherwise A y y
extract – data during justification action A y y
V3 – TU [VT]
justification opportunity
Sink
ignore - otherwise A y y
Source insertion – fixed stuff A y y
V4 – reserved
Sink ignore A y y
Source calculation PT y y
PT
defect EXC./DEG or DEG
NIM
dDEG based on 1 second PM
info
-x
algorithm
PT
PM – N_EBC NIM
count errored blocks count BIP violations
supported)
Protection Switching - SF NIM n y
PT y n/a
V5[1-2] – BIP2
Sink
Protection Switching - SD
NIM y y
Source insertion of BIP violation number PT y y
PT y yV5[3] - REI [REI-V]
Sink PM – F_EBC
NIM y y
Source insertion – fixed stuff “0” y yV5[4] – VC-2/12 [VT-
6/2] reserved Sink ignore y y

Source insertion PT y y
defect – RFI ??? PT y y
V5[4] – VC11 [VT1.5]
RFI Sink
PM ?? PT
Source insertion C y y
PT
defect -UNEQ NIM
y, ETSI specification requires
extra robustness for bursts of
errors
y
PT y n
PM – N_DS
NIM y n
consequent action - AIS PT y ?
consequent action - RDI PT y n
PT y n/a
V5[5-7] - UNEQ
Sink
NIM y y
Source creation
PT n n
defect – AIS
NIM y n
PT n n
PM – N_DS
NIM y n
consequent action - AIS PT n n
consequent action - RDI PT n n
consequent action - ERDI-server PT n n
PT n n
V5[5-7] - VC-AIS
Sink
NIM y n
A y (under study) y
defect – PLM
NIM n y
consequent action - AIS A y y
consequent action - RDI A n n
consequent action - ERDI-payload A n y
A y y
NIM n n
A y y
V5[5-7] - payload type
if value is ‘101’ use
extended signal label in
K4[1]
Sink
NIM n ?
Source insertion PT min 1 frame min 20 frames
PT
defect - RDI
NIM
5 frames 10 frames
PT y y
V5[8] – RDI [RDI-V]
Sink
PM – F_DS
NIM y y
A n/a y
Source insertion
PT n/a y
A n/a y
PT n/a ydefects - RDIs, RDIc, RDIp
NIM n/a y
PT n/a y
Z7[5-7] – ERDI
(SONET)
Sink
PM (RDIs, RDIc) – F_DS
NIM n/a y
In general VC [STS] NIMs are used in the following applications:
1. provide detection of connectivity and error defects for SNC/N protection switch; e.g. in dual node ring interworking and
(linear) path protection applications.
2. be used as a "work around" for tandem connection monitoring when TCOH processing (N1 bytes) is not supported
3. aid in fault localisation within a VC [STS] trail
4. performing single ended maintenance of a VC [STS] trail by monitoring at an intermediate [midspan] node.

Difference between sdh and sonet by helvoort

More Related Content

What's hot (20)

Viewers also liked (10)

Similar to Difference between sdh and sonet by helvoort (20)

Difference between sdh and sonet by helvoort