What is all this Concatenation stuff anyway? ”Bandwidth efficiency" Huub van Helvoort Member of...

What is all this Concatenation stuff anyway?

”Bandwidth efficiency"

Huub van HelvoortMember of Technical StaffLucent Technologiesemail: [email protected]

Concatenation Tutorial © Lucent Technologies 2002

T1X1.5 presentation T1X1.5/2002-096

2

© 2002 Lucent Technologies Concatenation Tutorial

ContentsContents

Bandwidth growth

Rate Comparison

Virtual Concatenation

Link Capacity Adjustment Scheme (LCAS)

Application

Standards

2

3


Bandwidth growth Rate Comparison



Application

Standards

3

4


SDH mapping schemeSDH mapping schemeInitial mappingMore MultiplexingContiguous Concatenation

4

C-4-64c

C-4-256c

C-4-16c

C-4-4cAU-4-4c VC-4-4c

AU-4-16c VC-4-16c

AU-4-64c VC-4-64c

AU-4-256c VC-4-256c

x 1

x 1

x 1

x 1

AUG-64

AUG-256

AUG-16

AUG-4

STM-256

STM-64

STM-16

STM-4

x 1

x 1

x 1

x 1

x 4

x 4

x 4

x 4

C-4

C-3

C-2

C-12

C-11VC-11

VC-12

VC-2

VC-3

TUG-2 TU-2

STM-0

AUG-1

VC-3

TUG-3

VC-4

AU-3

TU-11

TU-3

AU-4STM-1

x 1

x 1 x 1

x 1

x 1

x4

x 3

x 3

x 7

x 7

pointer processing

multiplexing

aligning

mapping

x 3

TU-12

5


SDH mapping scheme

Contiguous Concatenation (i.e.VC-4-Xc)• provides a payload area of X Container-4, see figure

5

125 s

X 260

C-4-Xc

X 261

VC-4-Xc

1

9

J1

B3

C2

G1

F2

H4

F3

K3

N1

1X-1

fixedstuff

• has one common set of POH, in the first column, used for the whole VC-4-Xc (e.g. BIP-8 covers all 261 X columns of a VC-4-Xc)

• columns #2 to #X are fixed stuff

6


SDH mapping scheme

Contiguous Concatenation• a VC-4-Xc is transported in X contiguous AU-4 in the STM-N signal

6

• the first column of the VC-4-Xc is always located in the first AU-4

• the pointer of this first AU-4 indicates the position of the J1 byte of the VC-4-Xc. The pointers of AU-4 #2 to #X are set to the concatenation indication to indicate a contiguously concatenated payload

• pointer justification is performed in common for the X concatenated AU-4s and X 3 stuffing bytes are used.

7


Bandwidth growth

Rate Comparison Virtual Concatenation


Application

Standards

7

8


Rate ComparisonRate Comparison

C-11

C-12

C-2

C-3

C-4

C-4-4c

C-4-16c

SDH - TDM

1.600 Mbit/s

2.176 Mbit/s

6.784 Mbit/s

49.536 Mbit/s

149.760 Mbit/s

599.040 Mbit/s

2.396 160 Mbit/s

C-4-64c 9.584 640 Mbit/s

Ethernet

ATM

ESCON

Fibre Channel

Fast Ethernet

Gigabit Ethernet

Data

10 Mbit/s

25 Mbit/s

200 Mbit/s

400 Mbit/s800 Mbit/s

100 Mbit/s

1 Gbit/s

10 Gb Ethernet10 Gbit/s

C-4-256c 38.338 560 Mbit/s

SDH container size/bit-rates vs. Data bit-rates

8

9


Rate ComparisonRate Comparison

C-3

C-3

C-4

C-4-4c

C-4-4c

C-4-16c

C-4-16c

SDH

20%

50%

67%

33%

67%

33%

42%

C-4-64c 100%

Ethernet

ATM

ESCON

Fibre Channel

Fast Ethernet

Gigabit Ethernet

Data

10 Mbit/s

25 Mbit/s

200 Mbit/s


100 Mbit/s

1 Gbit/s

10 Gb Ethernet 10 Gbit/s

Efficiency

Transport efficiencies

the solution:

Virtual Concatenation9

10


Bandwidth growth

Rate Comparison

Virtual Concatenation Link Capacity Adjustment Scheme (LCAS)

Application

Standards

10

11


Virtual ConcatenationVirtual Concatenation

Why:

• to transport contiguous concatenated signals in a network with NEs that do not support VC-n-Xc

Prerequisites:

• no requirements on existing NEs that transit VC-ns part of a Virtual Concatenation Group (VCG or VC-n-Xv)

11

• to provide a better bandwidth granularity to transport the new services with non-SDH bit rates

• no strict routing constraints for operators by compensating the differential delay caused by difference in optical path length

12



Mapping of C-n-Xc into X VC-n: a VC-n-Xv

12

125 s

m+11

1

9VC-n#X

over

head

VC-n-Xv

125 s

C-n-Xc

1

9

1 X m X

125 s

m+11

1

9VC-n#1

over

head

13


C-n-Xc C-n-Xc

C-n

C-n

C-n

1

2

X

X VC-n = VC-n-Xv


VC-n-Xc transport through a VC-n only network

13

C-n-Xc/C-n-Xv C-n-Xv/C-n-Xc

14



Differential delay is caused by:• geographically large ring with VC-ns from the same VC-n-Xv routed around the ring in different directions, delay is mainly due to fiber propagation (~5 s/km)

Y VC-ns

(Y<X) (X-Y) VC-ns

Ring

End-to-end trafficis VC-n-Xv

14

15



• networks with diversely routed path protected VC-ns, delay is mainly due to fiber propagation (~5 s/km)

End to end traffic: VC-n-Xv

Y VC-nson working path

(X-Y) VC-nson Protection path

Transportnetwork

Protectionpath

Working path

15

16



Provides additional transport sizes:

C-11-Xc

C-12-Xc

C-3-Xc

C-4-Xc

container

1 - 63

1 - 63

1 - 256

1 - 256

1.6 Mbit/s

2.0 Mbit/s

49 Mbit/s

150 Mbit/s

X in steps of

100.8 Mbit/s

137.1 Mbit/s

12.7 Gbit/s

38.3 Gbit/s

up to

16

17



C-12-5c

C-12-12c

C-12-46cC-3-2c

C-3-4c

C-3-8cC-4-6c

C-4-7c

SDH

92%

98%

100%100%

100%

100%89%

95%

C-4-64c 100%

Ethernet

ATM

ESCON

Fibre Channel

Fast Ethernet

Gigabit Ethernet

Data

10 Mbit/s

25 Mbit/s

200 Mbit/s


100 Mbit/s

1 Gbit/s

10 Gb Ethernet 10 Gbit/s

Efficiency

Transport efficiencies

17

18



Operation:

18

• distribute the payload to be transported bytewise over the members in the VCG

• provide byte alignment required for re-alignment after diverse routing delay compensation

• use the alignment indicator of each member to determine the experienced differential delay

19



from source (So) to sink (Sk):

Virtual Concatenation overhead:

19

• Multi Frame Indicator (MFI) the MFI is used to determine at the Sk the differential delay and re-align the received data to reconstruct the original

• Sequence Indicator (SQ) at the So each VC-n in the VCG is assigned an unique identifier to be used at the Sk for reconstruction of the original signal

20



Higher order overhead VC-4/3 POH H4H4 Byte

Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8

1st multiframe indicator MFI1 (bits 1-4)

1st multi-frame

number

2nd multi-frame

number

Sequence indicator LSB ( bits 5-8) 1 1 1 1 15 n-1

2nd multiframe indicator MFI2 MSB ( bits 1-4) 0 0 0 0 0

2nd multiframe indicator MFI2 LSB ( bits 5-8) 0 0 0 1 1

Reserved ("0000") 0 0 1 0 2

Reserved ("0000") 0 0 1 1 3

Reserved ("0000") 0 1 0 0 4

Reserved ("0000") 0 1 0 1 5

Reserved ("0000") 0 1 1 0 6

Reserved ("0000") 0 1 1 1 7

Reserved ("0000") 1 0 0 0 8

Reserved ("0000") 1 0 0 1 9

Reserved ("0000") 1 0 1 0 10

Reserved ("0000") 1 0 1 1 11

Reserved ("0000") 1 1 0 0 12

Reserved ("0000") 1 1 0 1 13

Sequence indicator SQ MSB ( bits 1-4) 1 1 1 0 14

Sequence indicator SQ LSB ( bits 5-8) 1 1 1 1 15

n

2nd multiframe indicator MFI2 MSB ( bits 1-4) 0 0 0 0 0 n+1

20

21



Lower order overhead

Reserved bitR

1 2 3 4 5 6 7 8 9 10 11

R

12

R

13

R

14

R

15

R

16

R

17

R

18

R

19

R

20 21 22 23 24 25 26 27 28 29 30 31 32

Bit number:

R R R R R R R R R R R RSequence IndicatorFrame Indicator

2nd stage: Virtual Concatenation control in K4 bit 2

Multiframe alignment bitsMFAS

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

0

20 21 22 23 24 25 26 27 28 29 30 31 32

MFAS

Bit number:

R R R R R R R R R R R R

Zero0

Reserved bitR 1st stage: Frame Aligment in K4 bit 1

Extended Signal Label

21

1 2 3 4 5 6 7 8

Bit number:

Signal Label

VC-2/VC-1 POH V5

REI RFI RDIBIP-2

1 0 1

22



Benefits:

• not restricted to the situation in which all the individual VC-ns are contained within a single Multiplex Section

22

• is transparent to intermediate network Elements, therefore it can be cost effectively deployed into an existing network without the need to upgrade all NEs

• can use protection schemes inherited from SDH per VC-n

• operators get the ability to implement channels that are more appropriate for the new router based applications by providing bandwidth granularity, right sized capacity, efficient mapping, traffic scalability and channelized high capacity SDH interfaces

23



Points for improvement:

• if one of the VC-n of a virtual concatenation group VC-n-Xv fails, the whole VCG fails

the solution:

LCAS

23

• data transport can have a variable requirement for bandwidth regarding the time of the day, or the day of the week

24


Bandwidth growth

Rate Comparison


Link Capacity Adjustment Scheme(LCAS)

Application

Standards

24

25


LCASLCAS

• provides the capability of temporarily removing member links that have experienced a failure

Features:

25

Prerequisites:

• LCAS assumes that in cases of capacity initiation, increase or decrease, the construction or destruction of the end-to-end path of each individual member is the responsibility of the Network and Element Management Systems.

• located in the virtual concatenation source and sink adaptation functions only

• provides a control mechanism to hitless increase or decrease the capacity of a VCG link to meet the bandwidth needs of the application

26


LCASLCAS

Operation:

• use virtual concatenation operation for differential delay compensation and de/re-construction of payload

26

• synchronization of changes in the capacity of the transmitter (So) and the receiver (Sk) shall be achieved by a control packet

• each control packet describes the state of the link during the next control packet

• changes are sent in advance, so that the receiver can switch to the new configuration as soon as it arrives.

27


LCASLCAS

In the forward direction, So to Sk:• Multi Frame Indicator (MFI)• Sequence Indicator (SQ)• Control (CTRL): IDLE - ADD - NORM - EOS - DNU - FIXED• Group Identification (GID)

In the return direction, Sk to So:• Member Status (MST)• Re-Sequence Acknowledge (RS-Ack)

For both directions:• Cyclic Redundancy Check (CRC) over the control packet

Note: MST and RS-Ack are identical in the control word of ALL members of the same VCG

Control packet content, LCAS overhead:

27

28


LCASLCAS

MST_a(n)RS-Ack_a

MFI_aSQ_nCTRL_nGID_aCRC_x

MFI_zSQ_pCTRL_pGID_zCRC_y

MST_z(p)RS-Ack_zVCG_a

member_n

VCG_zmember_p

Control packet content

28

information of member_n in VCG_a

information sent in control packet x of member_n in VCG_a

29


LCASLCAS

DNU

LA S T ?Y N

LAST?Y N

RENUMBERSEQUENCE

Y N

FDNU

FEOS

ROKRFAILMADD

ASSIGNSEQ# > EOS

FADD

IDLE

FIDLE

START

ADD

RFAIL ROK MREMOVE

RENUMBERSEQ# > EOS

FEOS

FIDLE

RFAILROK

REMOVE

ROK RFAIL MREMOVE

LA S T ?

NORM

RFAIL ROK MREMOVE

FNORM

FIDLE

State diagram of member(i)in the Virtual Concatenated group.

CEOS

CNORM

CEOS CNORM

send tomember(i-1)

FEOS FNORM

send tomember(i-1)

CNORMsend tomember(i-1)

send tomember(i-1)CEOS

CEOS CNORM

CEOS CNORM

send tomember(i-1)

see note 1

see note 3

see note 2

29

So side process

30


LCASLCAS

START

If the sink detects a change in thesequence numbers or the size ofthe VCG the RRS_ACK bit is inverted.

TSF FIDLE MREMOVE TSF FDNU FNORM FADD FEOS

OK

ROK

RFAIL

FAIL

TSF TSF MREMOVE

ROK

MADD

IDLE

RFAIL

FIDLE?Y

N

30

Sk side process

31


LCASLCAS

Higher order overhead

H4 byteBit1 Bit 2 Bit3 Bit 4 Bit 5 Bit 6 Bit 7 Bit 8

MS nibble1st multiframe indicator MFI1

LS nibble (bits 1-4)

1st multi-frame

no.

2nd

multi-frame

no.CRC-8 0 1 1 1 7

Member status MST 1 0 0 0 8


0 0 0 RS-Ack 1 0 1 0 10

Reserved (“0000”) 1 0 1 1 11

Reserved (“0000”) 1 1 0 0 12

Reserved (“0000”) 1 1 0 1 13

Sequence indicator SQ MSBs (bits 1-4) 1 1 1 0 14

Sequence indicator SQ LSBs (bits 5-8) 1 1 1 1 15

n

2nd multiframe indicator MFI2 MSBs (bits 1-4) 0 0 0 0 0

2nd multiframe indicator MFI2 LSBs (bits 5-8) 0 0 0 1 1

CTRL 0 0 1 0 2

0 0 0 GID 0 0 1 1 3

Reserved (“0000”) 0 1 0 0 4

Reserved (“0000”) 0 1 0 1 5

CRC-8 0 1 1 0 6

CRC-8 0 1 1 1 7


n+1

31

32


Multiframe alignment bitsMFAS

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

0

20 21 22 23 24 25 26 27 28 29 30 31 32

MFAS

Bit number:

R R R R R R R R R R R R

Zero0

Reserved bitR1st stage: Frame Aligment in K4 bit 1

Extended Signal Label

LCASLCAS

Lower order overhead

Reserved bitR

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

G ID

16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Bit number:

Sequence indicatorFrame count

2nd stage: Virtual Concatenation + LCAS control in K4 bit 2

CTRL R R R R

Ack

Member Status CRC-3

32

1 2 3 4 5 6 7 8

Bit number:

Signal Label

VC-2/VC-1 POH V5

REI RFI RDIBIP-2

1 0 1

33


LCASLCAS

NMS

So Sk Sk Sk

memn memn+1memn-1

Add two new members to the VCG

33

ADD

ADD SQ=5 ADD SQ=6

MST=OK

NORM SQ=4 EOS SQ=5

NORM SQ=5EOS SQ=6

(EOS SQ=4) IDLE IDLE

MST=OK

RS-Ack

RS-Ack

OK

OK

OK

FAIL FAIL

ADD SQ=6

34


LCASLCAS Remove one (last) member from the VCG

34

REMOVE

EOS SQ=3

(NORM SQ=3) (EOS SQ=4) IDLE

MST=FAIL

RS-Ack

IDLE SQ>3

OKOK

FAIL

IDLE

REMOVE

NMS

So Sk Sk Sk

memn memn+1memn-1

35


LCASLCAS Remove two members (not last) from the VCG

35

REMOVE

IDLE SQ>3

MST=FAIL

EOS SQ=3

(NORM SQ=3) (NORM SQ=4) (EOS SQ=5)

MST=FAIL

RS-Ack

IDLE SQ>3

OK OK OK

FAIL FAIL

REMOVE

IDLE IDLE

NMS

So Sk Sk Sk

memn memn+1memn-1

36


LCASLCAS

36

FAILED

(NORM SQ=3) NORM SQ=4 (EOS SQ=5)

MST=FAIL

DNU SQ=4

CLEAR

MST=OK

NORM SQ=4

traffic hit

decreasedcapacity

Network failure: temporarily remove a (not last) member from the VCG

OK OK OK

FAIL

OK

NMS

So Sk Sk Sk

memn memn+1memn-1

37


LCASLCAS Network failure: temporarily remove last member from the VCG

37

FAILED EOS SQ=3

(NORM SQ=3) EOS SQ=4

MST=FAIL

DNU SQ=4

CLEAR NORM SQ=3

MST=OK

EOS SQ=4

traffic hit

decreasedcapacity

OKOK IDLE

FAIL

OK

NMS

So Sk Sk Sk

memn memn+1memn-1

38


Bandwidth growth

Rate Comparison



Application Standards

38

39


Mapping DataMapping Data

SDH, SONET and OTN provide fixed rate channels, with virtualconcatenation and LCAS to provide the best match

39

to map the different types of Data into a fixed rate channel anew mechanism is defined:

Generic Framing Procedure (GFP) i.e. ITU-T recommendation G.7041/Y.1303

GFP is a generic mechanism to carry any packet signal (Ethernet, Fiber channel, ESCON) over fixed rate channels VC-n, VC-n-Xc, VC-n-Xv and LCAS providing flexible adjustment of a VC-n-Xv channel

most Data transport is packet based

40


Generic Framing ProcedureGeneric Framing Procedure

40

Ethernet IP/PPP FibreChannel

FICON ESCON other clientsignals

SDH/SONET path OTN pathother CBR path

GFP - Client Specific Aspects

(payload dependent)

GFP - Common Aspects(payload independent)

41


Generic Framing ProcedureGeneric Framing Procedure

41

PLI: PDU Length IndicatorPDU: Protocol Data UnitcHEC: core - Header Error ControlFCS: Frame Check Sequence (optional)

When no frames/characters are received, idle frames are inserted.

Transparent (8B/10B) Mapped:Individual characters of the client signal are mapped into fixed-length GFP frames.

Frame Mapped:Client frames are mapped into GFP frames.

PLI

cHECcHEC

(FCS)

PLI

GFP Frame

GFP payload4 - 65535

payload header

ClientPDU

0000

cHEC

Idle Frame

cHEC

42


Bandwidth growth

Rate Comparison



Application

Standards

42

43


StandardsStandards

43

Concatenation


Generic Framing Procedure (GFP)

Equipment

Equipment

Equipment Management Function

G.707 (10/2000)corr 1, corr 2*, add 1*

G.7042/Y.1305 (11/2001)*

G.7041/Y.1303 (11/2001)*

G.783 (02/2001)*

G.709 (02/2001)

G.798 (11/2001)

ITU-T

44


StandardsStandards

Concatenation, contiguous, virtual + LCAS (equipment Specific)

generic LCAS, refers to ITU

generic GFP, refers to ITU

T1.105*

G.7042*

G.7041*

44

EN 300 417-9-1 Concatenation, contiguous, virtual

ETSI

ANSI

THANK YOU

What is all this Concatenation stuff anyway? ”Bandwidth efficiency" Huub van Helvoort Member of...

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