overview of ng-sdh

1 Fujitsu and Fujitsu Customer Use OnlyNG-SDH Overview

Overview of NG-SDHOverview of NG-SDH


AgendaAgenda

Network status today and future Virtual Concatenation (VC) Link Capacity Adjustment Scheme (LCAS) Generic Frame Procedure (GFP) Testing tasks ITU-T standardization Instrument presentation


The Status TodayThe Status Today

SDH/ SONET - is the deployed technology in the core network with huge investments in capacity!

Ethernet - is the dominant technology of choice at LANs/WAN’s and well known at all enterprises worldwide!

Data traffic is still growing, but only at a slower speed than expected

All network topologies focusing on an IP/Ethernet ONLY approach are shifted to long-term future.

The future today:

Bring SONET/SDH and Ethernet together!


Storage Area Network (SAN)

New Customer ApplicationsNew Customer Applications

Virtual Private Network(VPN)

Edge Network

Core Network

Storage Server

LAN LANPC

Server

SONET/SDH

Ethernet

Fibre Channel

GFP-F

GFP-T


Mass market Carrier Class market

Asynchronous Synchronous

Dynamic Bandwidth Fixed Bandwidth

Connection less Connection oriented

Best Effort Service High Quality of Service

Ethernet vs. SONET/SDHEthernet vs. SONET/SDH

Ethernet SONET / SDH

How to solve all these challenges?


Worldwide Optical Network Equipment Market

0.0

2,000.0

4,000.0

6,000.0

8,000.0

10,000.0

12,000.0

14,000.0

16,000.0

18,000.0

1999 2000 2001 2002 2003 2004 2005 2006

Year

M

illi

on

s o

f U

.S.

Do

llar

s

NewGen

Traditional SDH/SONET

Source: Gartner


NNewewSSDH / DH / SSONETONET

OOverviewverview

VCGFP

LCAS

LAPS

Ethernet


Going into DetailsGoing into Details

Campus A

Ethernet

Optical CoreOptical Core

NetworkNetwork

Remote Servers

Storage Servers

Fibre Channel

SONET/SDHSONET/SDH

DWDMDWDM

SONET/ SDH

SONET/ SDH

SONET/ SDH

Campus B

EthernetFICON

Let‘s zoom in!Core NE

Edge NE


SONET/SDH/OTN

SO

NE

T M

UX

/DE

MU

X

Nat

ive

In

terf

aces

New SONET/SDH at the New SONET/SDH at the Edge

?

That’s “NG-SDH “

VC

VirtualConcatenation

LCAS

Link Capacity

Adjustment Scheme

GFP

Generic Frame

Procedure

LAPS

Ethernet

Ficon

Escon

Fibre Channel

Edge CoreAdaptation

Customer Operator


Customer needs EthernetCustomer needs Ethernet

Typical Ethernet Traffic

Connections

100

25

50

75

Mbit/s

time1 2 3 4

Ethernet Packet

Problem: How can we efficiently transport Ethernet over an existing SONET/SDH network?

Example: For 10M available SDH - Containers are...

VC-12 ...too small !

2.176 Mbit/s

VC-3 ... inefficient20%

48.38 Mbit/s

OR

Customer 3 = 100M

Customer 2 = 60M

Customer 1 = 10M


SDH Line RatesSDH Line Rates

10 M

Transport 10M Ethernet over SDH?

C-4-4c 0.599 Gbit/sC-4-16c 2.396 Gbit/sC-4-64c 9.584 Gbit/sC-4-256c 38.338 Gbit/s

Contiguous ConcatenationContiguous Concatenationonly large containers!

C-11 1.600 Mbit/sC-12 2.176 Mbit/sC-2 6.784 Mbit/sC-3 48.384 Mbit/sC-4 149.760 Mbit/s

SDH Payload Sizes

Standard Containers are inefficient!

Can’t 5 x VC-12 be concatenated?

?5x


CConcatenation -oncatenation -

CContiguous orontiguous orVVirtual ?irtual ?


AU-4 Pointers

MSOH

RSOH

VC-4-5 VC-4-6 VC-4-7 VC-4-8

VC-4-9 VC-4-10 VC-4-11 VC-4-12

VC-4-13 VC-4-14 VC-4-15 VC-4-16

VC-4-1 VC-4-2 VC-4-3 VC-4-4STM-16

ContiguousContiguousConcatenation

VC-4-4cc

AU-4 Pointers

MSOH

RSOH VC-4-1 VC-4-2 VC-4-3 VC-4-4

VC-4-5 VC-4-6 VC-4-7 VC-4-8

VC-4-9 VC-4-10 VC-4-11 VC-4-12

VC-4-13 VC-4-14 VC-4-15 VC-4-16

The block has to start at defined positionsdefined positions in the payloadThe block consists of consecutive VC-4-nsThere is only one pointer

STM-16

VirtualVirtualConcatenation

VC-4-7vv

AU-4 Pointers

MSOH

RSOH

VC-4-5 VC-4-6 VC-4-7 VC-4-8

VC-4-9 VC-4-10 VC-4-11 VC-4-12

VC-4-13 VC-4-14 VC-4-15 VC-4-16

VC-4-1 VC-4-2 VC-4-3 VC-4-4

Pointers

MSOH

RSOH VC-4-1 VC-4-2 VC-4-3 VC-4-4

VC-4-5 VC-4-6 VC-4-7 VC-4-8

VC-4-9 VC-4-10 VC-4-11 VC-4-12

VC-4-13 VC-4-14 VC-4-15 VC-4-16

The blocks can start at any positionany position in the payloadThe block consists of distributed VC-nsEach container has it‘s own pointer


VC NomenclatureVC Nomenclature

VC-nVirtual Container n

n=4, 3, 2, 12, 11

Defines the type of virtual containers, which will be virtually concatenated.

-XNumber of

virtuallyconcatenated

containers

All X Virtual Containers form together the

“Virtual Concatenated Group” (VCG)

vIndictor for

Virtual Concatenation

v = virtual concat..v = virtual concat..c = contiguous concat..c = contiguous concat..

Virtual Concatenated Group (VCG) of X VC-n containers!


VC Granularity and max. CapacityVC Granularity and max. Capacity

Nomenclature Granularity Max. Capacity

VC-4 –n v 149 M - 38.3G

VC-3 –n v 48 M - 12.7 G

VC-2 –n v 6.8 M - 434 M

VC-12 –n v 2.2 M - 139 M

VC-11 –n v 1.6M - 102 M

VC-4

VC-3

VC-2

VC-12

VC-11

Maximum Concatenation: = 256 containersMax. Capacity: = 256 x granularity


SDH - Virtual ConcatenationSDH - Virtual Concatenation

C-12-5v

C-12-12v

C-12-46vC-3-2v

C-3-4v

C-3-8vC-4-6v

C-4-7v

SDH

92%

98%

100%100%

100%

100%89%

95%

C-4-64v 100%

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 Ethernet 10 Gbit/s

efficiency

100M Ethernet STM-1= 64 x VC-12

VC-12-5v

VC-12-46v

2x 10M Ethernet VC-12-5v

8x E1 Services

Example:

More services integrated- by using VC!


VVirtualirtualCConcatenationoncatenation ++DDifferentialifferentialDDelayelay


Virtual Concatenated GroupsVirtual Concatenated Groups

Answer:The containers do not know it!That’s the job of the network management!

Question:How does a container know that it belongs to a VCG?

Question:Which containers can belong to the same group?

Answer:They must all start at one port!And they must all end at one port!

A

B

A

B

A A


VC-4

VC-4

VC-4

VC-4

Virtual Container IndicatorVirtual Container Indicator

Problem:How to distinguish between VCG members of one group?

SQ=0

SQ=1

SQ=2

SQ=3

Solution:Give each member an individual “number plate”! Sequence Indicator (SQ)

Result: VCG members can now be distinguished and sorted!


Time Stamp MechanismTime Stamp Mechanism

VC-4

VC-4

VC-4

VC-4

SQ=0

SQ=1

SQ=2

SQ=3

Problem:How do we know that members arriving together started together?

Solution:Give each VCG an individual number Frame Counter (FC)

FC = 0

SQ=0

SQ=1

SQ=2

SQ=3

FC = 1

SQ=0

SQ=1

SQ=2

SQ=3

FC = 0

SQ=0

SQ=1

SQ=2

SQ=3

FC = 1

SQ=0

SQ=1

SQ=2

SQ=3

FC = 0

SQ=0

SQ=1

SQ=2

SQ=3

FC = 2

SQ=0

SQ=1

SQ=2

SQ=3

FC = 1

SQ=0

SQ=1

SQ=2

SQ=3

FC = 0

SQ=0

SQ=1

SQ=2

SQ=3

FC = 2

SQ=0

SQ=1

SQ=2

SQ=3

FC = 3

SQ=0

SQ=1

SQ=2

SQ=3


Transporting Concatenated SignalsTransporting Concatenated Signals

VC-4-2v

Virtual Concatenation

VC-4 #2

VC-4 #1

VC-4 #1

Path 2

Path 1

VC-4 #2

Differential Delay

VC-4 #2

VC-4 #1

VC-4 #2

VC-4 #1

Contiguous Concatenation

VC-4-4c

C-4 C-4

C-4 C-4

C-4 C-4

C-4 C-4

NENEOne Path

C-4 C-4

C-4 C-4

Core Network


Storage

DemappingArrival

SQ = 1FC = max

SQ = 0FC = max

SQ = 3FC = max

SQ = 1FC = max

SQ = 0FC = max

SQ = 3FC = max

SQ = 1FC = 0

SQ = 0FC = 0

SQ = 2FC = max

SQ = 3FC = 0

SQ = 1FC = max

SQ = 0FC = max

SQ = 2FC = max

SQ = 3FC = max

SQ = 1FC = 0

SQ = 0FC = 0

SQ = 3FC = 0

SQ = 1FC = 1

SQ = 0FC = 1

SQ = 3FC = 1

SQ = 1FC = max

SQ = 0FC = max

SQ = 2FC = max

SQ = 3FC = max

SQ = 1FC = 0

SQ = 0FC = 0

SQ = 3FC = 0

SQ = 2FC = 0

SQ = 1FC = 1

SQ = 0FC = 1

SQ = 3FC = 1

SQ = 1FC = max

SQ = 0FC = max

SQ = 2FC = max

SQ = 3FC = max

SQ = 1FC = 0

SQ = 0FC = 0

SQ = 3FC = 0

SQ = 2FC = 0

SQ = 1FC = 1

SQ = 0FC = 1

SQ = 3FC = 1

SQ = 1FC = 2

SQ = 0FC = 2

SQ = 2FC = 1

SQ = 3FC = 2

SQ = 1FC = 0

SQ = 0FC = 0

SQ = 3FC = 0

SQ = 2FC = 0

SQ = 1FC = 1

SQ = 0FC = 1

SQ = 3FC = 1

SQ = 1FC = 2

SQ = 0FC = 2

SQ = 2FC = 1

SQ = 3FC = 2

SQ = 1FC = 0

SQ = 0FC = 0

SQ = 3FC = 0

SQ = 2FC = 0

SQ = 1FC = 1

SQ = 0FC = 1

SQ = 3FC = 1

SQ = 1FC = 2

SQ = 0FC = 2

SQ = 2FC = 1

SQ = 3FC = 2

SQ = 1FC = 3

SQ = 0FC = 3

SQ = 3FC = 3

SQ = 2FC = 2

Stop

Way 1

Way 2

Way 3 - delayed

Way 4

VCG ReassemblyVCG Reassembly


VVCCFFramingraming


Where are the VC bytes?Where are the VC bytes?

•Carried in one bit in K4-Byte• 32 frame Multi-Frame

High Order VC Low Order VC

• Information in H4 Byte• 16 frame Multi-Frame

F2H4F3K3

B3C2G1

J1

N1

VC-3 / VC-4out of

VC-3-Xv / VC-4-Xv

J2N2K4

V5 VC-2 / VC-11/VC-12out of

VC-2-Xv / VC-11-Xv /VC-12-Xv


High Order VC - H4 byte - non LCASHigh Order VC - H4 byte - non LCAS

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

MFI1 MFI2

n

H4 Byte Multi-Frame

Bit 1 - 4 Bit 5 - 8

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

MFI1 (bit 1-4)

0 000

0 100

0 010

0 110

0 001

0 101

0 011

0 111

1 000

1 100

1 010

1 110

1 001

1 101

1 011

1 111

MFI2 (bit 1-4)

MFI2 (bit 5-8)8 bit

SQ (bit 1-4)

SQ (bit 5-8)8 bit

Time for transmitting ONE multi-frame: 16 byte x 125µs = 2ms


Higher Order Path H4: MFI1 / MFI2Higher Order Path H4: MFI1 / MFI2

MFI2 (8)

0

1

2

The complete multiframe has

MFI1=16 * MFI2=256= 4096 steps.

Target for delaycompensation of 512ms

012

4095

255

0

1

15

MFI1 (4)

0

1

15

0


MFI 1 - Multi Frame Indicator 14 bits - Counter incremented at each individual frameOne MFI1 multi-frame = 16 framesCounts from 0 to 15

MFI 2 - Multi Frame Indicator 28 bits - Counter incremented every 16 frames - after a

complete MFI1 multi-frameCounts from 0 to 255

High Order VC Frame Counter:MFI1 x MFI2 = 16 x 256 = 4096Max. tolerable Differential Delay = 4096 x 125 µs = 512ms

SQ - Sequence Indicator8 bits - Transmitted once every MFI 1 multi-frameMax. number of High Order VCG members = 256

High Order VC - H4 byteHigh Order VC - H4 byte


K4 byte (VC-2, 11, 12)

bit 1:Extended Signal label - 32 frame multi-frame

bit 2: Low order Virtual concatenation

bit 2: 32 frame MF should be in phase with b1 multi-frame

1 72 3 4 5 6 8 9 1210 11 13 1914 15 16 17 18 20 21 2422 23 25 3126 27 28 29 30 32

ReservedMFAS = Multiframe

alignment bits0111 1111 110

Extended Signal Label 0

1 72 3 4 5 6 8 9 1210 11 13 1914 15 16 17 18 20 21 2422 23 25 3126 27 28 29 30 32

Reserved = 0Frame Count (FC)

Sequence Indicator (SQ)

Low Order VC - K4 byteLow Order VC - K4 byte

Time for transmitting ONE multi-frame:Length of MF x Frame Repetition Rate32 bit x 500µs = 16ms


Low Order VC Frame Counter:FC x Length of Multi-Frame x Frame Repetition RateMax. tolerable Differential Delay = 32 x 32 x 500µs = 512ms

FC - Multi Frame Indicator5 bits - Counter incremented with each 32 bit multi-frameCounts from 0 to 31

Low Order VC - K4 byteLow Order VC - K4 byte

SQ - Sequence Indicator6 bits - Transmitted once every 32 bit multi-frameMax. number of Low Order VCG members = 64


Virtual Concatenation - BenefitsVirtual Concatenation - Benefits

VCBENEFITS

EconomicalRe-use core network equipment invest only at the edge

Well-knownSONET/SDH is well

engineered & reliable & trained

Efficient & Scalable

Fine granularity & multi-path capability

Low Investmentdeployment only on customer demand Fast ROI


Challenges ahead...Challenges ahead...

How can path bandwidth be increased or decreased? Dynamic Bandwidth Provisioning “..bring an additional truck on the road..”

VC-3 #1VC-3 #2

VC-3 #?

VC-4 #1VC-4 #3

VC-4 #2

FAILED

How can we ensure QoS for data services? VCG - Protection one VC container fails - the whole Virtual

Concatenation Group (VCG) fails!


LLinkinkCCapacityapacityAAdjustmentdjustmentSSchemecheme


Los Angeles

Seattle

Dallas

Washington

Chicago

San FranciscoSan Jose

Houston Orlando

Atlanta

New York

Boston

Kansas CityDenver

Columbus

Los Angeles

Seattle

Dallas

Washington

Chicago


Houston Orlando

Atlanta

New York

Boston

Kansas CityDenver

Columbus

Location A

Location B

Bandwidth Provisioning - todayBandwidth Provisioning - today

50Mbit/s Ethernet Private Line (VC-3-1v/ STS-1-1v)

The customer now requires 100Mbit/s

But: Traffic will be interrupted to bring 100M into service!!

Operator manually sets up a 2nd path using the network management system 100M = VC-3-2v / STS-1-2v


Los Angeles

Seattle

Dallas

Washington

Chicago


Houston Orlando

Atlanta

New York

Boston

Kansas CityDenver

Columbus

Los Angeles

Seattle

Dallas

Washington

Chicago


Houston Orlando

Atlanta

New York

Boston

Kansas CityDenver

Columbus

LCAS - Add Bandwidth hitlessLCAS - Add Bandwidth hitless

Operator manually provisions additional 50M path

Location A

Location B

Operator installs VC & LCAS edge equipment

LCAS protocol runs between the two edge NE! NE negotiate - when the additional path gets

valid and into service!

LCAS Protocol

NE

NE

LCAS Succeeds A connection with 100M is in service!

100M Ethernet Link


GGeneralizedeneralizedCControlontrolPPacketacket


VC & LCAS Control PacketVC & LCAS Control Packet

Frame Counter

MFI

VCGSequence Indicator

SQ


Information

LCASError

Protection

CRC

LCASMember

Status

MST

LCASControl

Commands

CTRL

LCASSource

Identifier

GID

LCASResequence

Acknow-ledgement

RS-Ack

LCAS Information

Information Packets exchanged between the two edge network elements to adjust the bandwidth.


Control Packet - MFIControl Packet - MFI

CRCMSTMFI SQ CTRL GID RS-Ack

MFI - Multi Frame Indicator Field it is a frame counter which will be incremented with each frame All VCG members will have the same counter value reaching the maximum counter value the counter restarts at “0”

MFI is necessary for realigning virtual concatenated containers of one VCG at the sink determing the differential delay between members of the same VCG

MFI = 0 MFI = 1 MFI = 2 MFI = max MFI = 0 MFI = 1

Sink Source


Control Packet - SQControl Packet - SQ


SQ - Sequence Indicator Field each member of a VCG has it own, unique sequence number the values start at “0” - max. 63 (LO) or 255 (HO)

SQ is necessary for differentiating the members of a virtual concatenated group (VCG)

MFI = 0

SQ = 0

MFI = 0

SQ = 1

MFI = 1 MFI = 2 MFI = 255 MFI = 0

MFI = 1 MFI = 2 MFI = 255 MFI = 0

SQ = 0 SQ = 0 SQ = 0 SQ = 0

SQ = 1 SQ = 1 SQ = 1 SQ = 1

Sink SourceVCG

Member 0

Member 1


VCG Link

EOS

IDLEADD

NORM

Sink Source

Control Packet - CTRLControl Packet - CTRL

CTRL - Control Field for LCAS is used to transfer information from the source to sink it contains the LCAS control commands to initiate or terminate the

bandwidth adaptation process


CTRL - is used to synchronize source and sink LCAS process provide LCAS status information about every individual VCG

member



LCAS Control words FIXED (0000) - Non LCAS Mode

Indication that LCAS mode is not used at the source- fixed bandwidth


ADD (0001)- Increase bandwidth of a VCG A container, which is currently not a member of the group, but is “asking” to

become an active member of a VCG.

NORM (0010) - Normal Transmission This container is an active member of a VCG and currently transporting client

payload



DNU (1111) - Do Not Use The payload of this container can’t be used, because the sink reported FAIL

status But it is still a member of the VCG, but currently “out of service”


IDLE (0101) - Currently not in use Pre-provisioned container, but currently not in use or about to be removed

from a group - is not carrying client payload. At initiation of a new VCG, members should have CTRL=IDLE state

LCAS Control words EOS (0011) - End of sequence & Normal Transmission

This container is the last active member of a VCG and currently transporting client payload.


Control Packet - GIDControl Packet - GID


GID - Group Identification Bit is a “security” mechanism to ensure that all members are

belonging to the same VCG every member of a VCG has the same GID bit value GID content is a PRBS 215-1

GID - is used to verify that all members are coming from the same source identify all members of a VCG

Member 0

Member 1

MFI = 0SQ = 0GID = 0




MFI = 1SQ = 1

GID = 0

MFI = 2SQ = 1

GID = 1

MFI = 255SQ = 0GID = 0


MFI = 255SQ = 1

GID = 0

MFI = 0SQ = 1

GID = 1


Control Packet - MSTControl Packet - MST


MST - Member Status field reports the status for every member of a VCG from sink to

source (= back channel) with one bit there are two MST states for each individual VCG member:

OK = 0 or FAIL = 1

Member Status information is spread across multiple frames. corresponds directly to a certain VCG member is always reported for the max. number of VCG members (64 or

256) should report MST=FAIL on initiation of a new VCG should switch to MST=OK on reception of ADD, NORM or EOS


Control Packet - RS-AckControl Packet - RS-Ack


RS-Ack - Re-sequence Acknowledge bit If any sequence number changes are detected at the sink the RS-

Ack Bit is toggled (from “0” to “1 or from “1” to “0”) BUT only after the status for ALL members have been evaluated An RS-Ack toggle will be an indication for the source that the sink

has accepted the new member status.


CRC - Cyclic Redundany Check the content of a control packet is protected by a CRC if errors are detected the control packet is rejected


CControlontrolPPacketacketTTransportransportHHigh & igh & LLow Orderow Order


Where are the LCAS bytes?Where are the LCAS bytes?

J2N2K4

V5VC-2 / VC-11/VC-12

out ofVC-2-Xv / VC-11-Xv /VC-12-Xv

F2H4F3K3

B3C2G1

J1

N1

VC-3 / VC-4out of

VC-3-nv / VC-4-nV

*CP = Control Packet

• LCAS info aligned with VC info• Carried in one bit in K4-Byte

• 32 frame Multi-Frame

High Order LCAS Low Order LCAS• LCAS info aligned with VC info• Information also in H4 Byte• 16 frame Multi-Frame


Low Order Control PacketLow Order Control Packet

CRC-3Member StatusSequence

Indicator CTRLGID

Spare

RS-ACK

J2N2K4

V5VC-2 / VC-11/VC-12

out ofVC-2-Xv / VC-11-Xv /VC-12-Xv

Low Order VC & LCASHow to build a multi-frame control packet?• Filter from each K4 byte only bit no. 2• Store bit no. 2• After 32 VCs, one complete VC & LCAS control packet was received.

Frame Count

1

K4

b2Filter

32x

2

K4

b2

3

K4

b2

4

K4

b2

5

K4

b2

6

K4

b2

7

K4

b2

8

K4

b2

9

K4

b2

11

K4

b2

12

K4

b2

13

K4

b2

14

K4

b2

15

K4

b2

16

K4

b2

10

K4

b2

17

K4

b2

18

K4

b2

19

K4

b2

20

K4

b2

21

K4

b2

22

K4

b2

23

K4

b2

24

K4

b2

25

K4

b2

27

K4

b2

28

K4

b2

29

K4

b2

30

K4

b2

31

K4

b2

32

K4

b2

26

K4

b2

Virtual ConcatenationInformation

LCAS Information


High Order LCAS - H4 byteHigh Order LCAS - H4 byte

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

MFI1 MFI2

n

H4 Byte Multi-Frame

Bit 1 - 4 Bit 5 - 8

MFI1 (bit 1-4)

0 000

0 100

0 010

0 110

0 001

0 101

0 011

0 111

1 000

1 100

1 010

1 110

1 001

1 101

1 011

1 111

MFI2 (bit 1-4)

MFI2 (bit 5-8)8 bit

SQ (bit 1-4)

SQ (bit 5-8)8 bit

Time for transmitting ONE multi-frame: 16 byte x 125µs = 2ms

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

Reserved “0000”

CRC-8

CRC-88 bit

Member Status (MST)

Member Status (MST)8 bit

RS-Ack “000x”1 bit

GID “000x”1 bitCTRL4 bit


““ADD” ExplainedADD” Explained

Request from NMS to increase bandwidth on a existing link.1Source

Actions for the currently unequipped container:a) assign a valid sequence indicator (SQ=currently highest +1)b) change CTRL=ADD (from CTRL=IDLE)

2Source

Sink replies with MST=OK after detection of the new member3Sink

Sink acknowledges the new status with the beginning of the next multi-frame (RS-Ack toggles)4Sink

With reception of acknowledgement source will changea) the status of the last member from CTRL=EoS to NORMb) the status of the new member from CTRL=IDLE to EoS

5Source

After the reception of the new member with CTRL=EoS Sink will start the demapping process with the next container!7Sink

Source starts to map payload (traffic) information in the next upcoming container6Source


LCAS - ITU-T State DiagramLCAS - ITU-T State Diagram

NMS LCAS Sk Sk Sk

CTRL=ADD

CTRL=ADD

CTRL=NORM CTRL=EOS

CTRL=NORM CTRL=EOS

MST=OK

MST=OK

mema(new) mema +1(new)memn-1(EOS)Note 1

Note 2

Note 3

Note 4

Note 5

Note 6

Note 7

Add cmnd

connectivitycheck

connectivitycheck


Sink detects an failure of one member Sink changes the member status of this member to FAIL On detection of this new member status Source will set

CTRL from NORM or EoS to DNU (Do not use) Sink does not demap the payload anymore.

Temporary FailureTemporary Failure

Sink detects the clearance of the failure status Sink sets the member status of this member to OK On detection of this new member status Source will set

CTRL to NORM or EOS again Sink will now demap

Auto Recovery of VC links possible


LLCAS CAS summarysummary


Information sent incontrol packet x

of container n in VCG A

Information sent incontrol packet y

of container p in VCG B

Information Flow ChartInformation Flow Chart

Information for status ofcontainer p of VCG B

Information for status ofcontainer n of VCG A

MFI_A

SQ(n)

CTRL(n)

CRC_x

GID_A

MST_A(n)

RS-Ack_A

MST_B(n)

RS-Ack_B

MFI_B

SQ(p)

CTRL(p)

CRC_y

GID_B

Link of VCG B

Link of VCG ANE A NE B


Control Packet OverviewControl Packet OverviewInformation Direction

Source Sink

MFIMulti-Frame Indicator is an counter• to distinguish several VCGs* from each other• necessary to compensate for Differential Delay

SQSequence Indicator is an counter• to differentiate individual VC-n containers within a VCG*• to re-sequence VC-n containers at the termination point in case that differential delay occured

CTRLLCAS Control Words are• the actual commands which will show the status of containers from a VCG* initiate bandwidth changes• FIXED - container in NON-LCAS mode• ADD - container which will be added to a VCG• REMOVE - container which will be removed from a VCG• NORM - container as part of an active VCG• EOS - last container of an active VCG• DNU - container with failures(“do not use”)

*VCG = Virtual Concatenated Group


Control Packet OverviewControl Packet OverviewInformation Direction

Source Sink

GIDGroup Identification Bit is• an additional verification mechanism to secure that all incoming VCG members belong to one group

CRCCyclic Redundancy Check is a• protection mechanism to detect bit errors in the Control Packet

MSTMember Status Field is• an mechanism, where the sink reports to the source which VCG members are currently and correctly received

RS-AckRe-sequence acknowledgement is• an mechanism, where the sink reports to the source the detection of any additions/removals to/from the VCG

*VCG = Virtual Concatenated Group


Link Capacity Adjustment SchemeLink Capacity Adjustment Scheme

LCASBENEFITS

Flexible & scalableOffers variable VC bandwidth in real-time!

Cost EfficientNew NE necessary

only at the edgeTransparent to

core network

Enables Value added servicesBandwidth on demand”Soft” Protection99.999% up-time

RestorationVirtual Concatenation

link protection & recovery


Challenges aheadChallenges ahead

Rate adaptation between asynchronous clients and synchronous transport network

Asynchronous Rates

Synchronous Rates

Efficient & suited mappings for all diverse data clients!

“...one mapping fits all...?!?”

SONET/SDH


GGenericenericFFrameramePProcedurerocedure


SONET/SDH

SO

NE

T M

UX

/DE

MU

X

Nat

ive

In

terf

aces

New SONET/SDH at the New SONET/SDH at the Edge

?

That’s “ New SONET/SDH “

VC


LCAS

Link Capacity

Adjustment Scheme

GFP

Generic Frame

Procedure

LAPS

Ethernet

Ficon

Escon

Fibre Channel

Edge CoreAdaptation

Customer Operator


GFP - Layer ModelGFP - Layer Model

GFP - Client Specific Aspects (payload dependent)

GFP - Common Aspects (payload independent)

SONET/SDH VC-n Path

OTN ODUk Path

Others(e.g. Fibre)

Ethernet IP/PPP Fibre Channel OthersClients

GFP

Transport

Frame Mapped Transparent Mapped

ESCON


Generic Frame ProcedureGeneric Frame Procedure

G.7041 Generic Frame Procedure defines Client encapsulation - for transport over SONET/SDH or

OTN networks Frame formats - for various clients Mapping Procedures - for client signals into GFP

Why do we need a new framing procedure? simple and scalable traffic adaptation for different

transport rates flexible approach for data transmission which requires

stringent delay, QoS


SStructure tructure ooff GGFP - FP - FFramesrames


PayloadArea

8 bit

Core Header

GFP Payload Area transports higher layer specific information Length 4 to 65535 byte

GFP Frame OverviewGFP Frame Overview

Client Payload Field contains client frames (GFP-F) orclient characters (GFP-T)

ClientPayload

Information

Payload Headers gives type of client and supports client specific management procedures Includes CRC detection & correction Length 4 to 64 byte

PayloadHeaders

Core Header contains the length of the payload area and start of frame info and CRC-16 error detection & correction Length 4 byte

Optional Payload FCS protects the client payload information field CRC-32 Length 4 byte

OptionalPayload FCS

GFP gets scrambled before transmission!


GFP - Common AspectsGFP - Common Aspects

PayloadArea

Core Header

8 bit

PLIPLI

cHECcHEC

ClientPayload

Information

PayloadHeaders

OptionalPayload FCS

4 byte

4 to 65535 byte

8 bit

X=4-64 byte

0 to 65535-X byte

4 byte

4 byte


GFP - Core HeaderGFP - Core Header

PayloadArea

Core Header

cHEC - Core Header Error Control contains a CRC-16 error control code to protect the integrity

of the core header. It enables

to correct a single bit error to detect multiple bit errors

PLI - PDU Length Indicator 16-bit field contains a binary number,

representing the length of the payload area:

min.: 4 byte (PLI = 00 04hex) max.: 65535 byte (PLI = FF FFhex) PLI = 0hex to 3hex reserved for control

frames

PLIPLI

cHECcHEC

1

1

1

1

1 2 3 4 5 6 7 8


GFP -Control FramesGFP -Control Frames

GFP IDLE Frames The smallest, possible GFP frame with

only 4 byte long PLI = 00 00hex

IDLE frames are necessary for rate adaptation process robustness of the frame synchronization

process

IDLE Frame

PLI =00PLI= 00

cHEC = 00cHEC = 00

GFP Control Frames are used in the managment of the GFP connection.

Four Control Frames are available PLI= 00 00hex to PLI = 00 03hex

BUT only one Control frame is currently specified:


GFP - Payload HeaderGFP - Payload Header

Payload Type FieldProvides information about

content & format of the Client Payload Information

indicates different GFP frame types distinguishes between different services in a

multi-service environment

PayloadArea

Core Header

ClientPayload

Information

PayloadHeaders

OptionalPayload FCS

Payload Type

ExtensionHeader

FieldExtension Header Field supports technology specific data link

headers, e.g. virtual link identifier source/destination address Class of Service

Three Extension Header Variants are currently defined for point-to-point or ring configurations


GFP - Payload HeaderGFP - Payload Header

PTI - Payload Type Identifier 3-bit field, which indicates the type of GFP client frameCurrently defined PTI = 000 Client Data PTI = 100 Client Management PTI = Others Reserved

PFI - Payload FCS Indicator 1-bit field indicates the PFI = 1 Presence PFI = 0 Absence of the optional payload Frame Check Sequence (pFCS) field

EXI - Extension Header Identifier 4-bit field indicates the format of the Extension Header FieldCurrently defined EXI = 0000 Null Extension Header EXI = 0001 Linear Frame EXI = 0010 Ring Frame EXI = Others Reserved

PayloadType

ExtensionHeader

Field

PTI PFI EXIUPI

tHECtHEC

1

1

1

1

1 2 3 4 5 6 7 8

UPI - User Payload Identifier 8-bit field identifies the type of client/service

encapsulated in the GFP Client Payload Field Interpretation of UPI values is different for

Client data frames (PTI=000) or Client management frames (PTI=100)

More details on the next slides

tHEC - Type Header Error Control 16-bit error control code to correct one bit error or to detect multiple bit errors in the payload type field


GFP - Extension HeaderGFP - Extension Header

Extension Header Field supports technology specific data link

headers, e.g. virtual link identifier source/destination adress Class of Service

it is 0-60 byte long and indicated in the Type field (EXI)

Three Extension Header Variants are currently defined for point-to-point or ring configurations

EXI = 0000 Null Extension Header EXI = 0001 Linear Frame EXI = 0010 Ring Frame EXI = Others Reserved

PayloadArea

Core Header

ClientPayload

Information

PayloadHeaders

OptionalPayload FCS

Payload Type

ExtensionHeader

Field


Extension HeaderField

GFP - Linear Extension HeaderGFP - Linear Extension Header

CID - Channel ID 8-bit field to indentify up to 256 independent GFP

channels over the same link

eHEC - Extension Header Correction 16-bit error control code to correct on bit error to to detect multiple bit errors in the extension

header field

eHECeHEC

CIDSpare

1

1

1

1

tHEC

tHEC

Type

Type1

1

1

1

Linear Frame Extension Header (EXI = 0001) applies to linear (point-to-point) configurations, where

several independent clients or services are aggregated to one transport path

Spare 8-bit field for future use

Extension Header for ring frame for further study


GFP - Frame & Client MultiplexingGFP - Frame & Client Multiplexing

GFP Signals from multiple ports or clients are multiplexed on a frame by frame basis• GFP IDLE cells are transmitted in case of no other clients

• GFP - a mapper build inside

eHECeHEC

CIDSpare

Linear Extension Header

1..256 signals

GFPMux

GFP Streamswith different clients

IDLE Insertion

CID=0CID=2 CID=1CID=1

CID=0 CID=0CID=0

CID=1CID=1 CID=1

CID=2 CID=2CID=2


CIDSpare

eHECeHEC

PTI PFI EXIUPI

tHECtHEC

GFP - Frames OverviewGFP - Frames Overview

PayloadArea

Core Header

8 bit

PLIPLI

cHECcHEC

ClientPayload

Information

PayloadHeaders

OptionalPayload FCS

PayloadType

ExtensionHeader

Field

4

4 - 65535


GGFP - FP - OOperationperationMModesodes


GFP IDLE Frame: Rate Adaptation (“stuffing”)

GFP Management Frame: under study

GFP Operation ModesGFP Operation Modes

GFP-T (Transparent Mapped): Client characters are directly mapped in GFP-T frames e.g. Fibre Channel Fixed length GFP frames Minimal Latency

00

GFP-F (Framed Mapped): For packet oriented clients, e.g. Ethernet One Client Packet = packed in one GFP frame (1:1) Minimal overhead


GFP Operation ModesGFP Operation Modes

GFP-T

1GigE IDLELE EthEth. Frame IDLEEthernet Frame

GFP-F

Frame by Frame

GFPEthernet FrameGFP GFP GFP EthGFPGFPEth. Frame

TransparentGFP TransparentGFP TransparentGFP GFP

GFP GFP Header or IDLE frames

Block by Block

fixed

variable

GFP


GFP-F Client vs. Transport RateGFP-F Client vs. Transport Rate

Variable Client Rate

GFP-F

t

Mbit/s

FIFO

IDLEs

GFP-F Mapper

+

Mapper

Constant Transport Rate

t

Mbit/s

GFP-F IDLEs

Client

EthernetFast EthernetGigabit EthernetIPPPP


GFP-T mapping procedureGFP-T mapping procedure

1GigE IDLELE EthEth. Frame IDLEEthernet Frame

1. Decoding: 1 GbE GFPData Codes Data Bytes (8 Bit)Control Codes Control Code Indicator (4 Bit)

8B/10B Codewords

2. 64B/65B Block Code

Leading bit 8-byte block

Re-arranging of leading bits to the end


GFP-T mapping procedureGFP-T mapping procedure

3. CRC-16 calculation

CRC-16

GFP Core header &

Payload header

Superblocks Superblocks Superblocks* * * *

Optional GFP FCS

4. Superblock formation and GFP OH


GFP-T Client vs. Transport RateGFP-T Client vs. Transport Rate

GFP-T Mapper

Mapper

Decoder/ Coder

100+x %

GFP-T

t

Mbit/s

Effective Payload

Constant Client Data Rate

100 %

Client IDLEs

Fibre ChannelESCONFICONGigabit Ethernet10 GigEAnything!

t

Mbit/s

GFP Overhead

Constant Transport Rate

Effective Payload

Client IDLEs


GGFP-F FP-F &&

GGFP-T FP-T


GFP-F vs. GFP-TGFP-F vs. GFP-T

GFP-F GFP-T• used for connections where

efficiency and flexibility are key

• 1:1 relation between service frame/paket and GFP frame

• buffering necessary, this increases latency

• preferred option for GE and IP

• good for statistical multiplex services

• for applications that are sensitive to latency or unknown physical layers

• all code words from physical layer are transported

• primarily targeted at SANs


GGFP - FP - FFramingramingPProceduresrocedures


GFP - Frame DelineationGFP - Frame Delineation

GFP uses•the Payload Length Indicator and•the Core Header protection field for frame synchronization

PLI

PLI

cHEC

cHEC

CRC-16

PLI

Payload Length Indicator

PayloadGFP

Variable length 4 to 65539 Byte

..... it’s all about synchronisation!


GFP - Frame DelineationGFP - Frame Delineation

110100010010111110100100011010010101001111110010010100101001000101111010010101001010101010010111101

PLI cHECComparer

2 byte 2 byte

CRC-16

1. HUNT State• Searching for a correct formated 4 byte Core Header• Byte by Byte search• Bit Error Correction = disabled

Expected next Core Header

2. PreSync State• Jump to the next correct Core Header using PLI info • Frame by frame search for x consecutive correct cHECs• Bit Error Correction = disabled• Successful? - Yes3. Sync State

• Jump to the next frame using PLI• Single Bit Error Correction = enabled• Detection of Multiple Bit Errors?


GGFP - FFP - FPPayloadayloadSSpecificspecifics


GFP & Ethernet MAC PayloadGFP & Ethernet MAC Payload

Source Address

Destination Address

Preamble

Start of Frame Delimeter

Length/Type

MAC Client

Pad

Frame Check Sequence

Bytes

7

1

2

6

6

4

46-1500

tHEC

Type

PLI

cHEC

GFP Extension Header

GFP Payload

2

2

2

2

0-60

AsClient

Bytes

Ethernet MAC Frame GFP-F Frame

Source Address

Destination Address

Length/Type

MAC Client

Pad


Ethernet Inter-Packet-Gaps are deleted before encapsulation and restored after transmission

Byte alignment and bit identification is maintained


IP & PPP PayloadIP & PPP Payload

Flag

ControlAddress

PPP Type

PPP Information

Pad


Bytes

1

2

11

4

tHECType

PLIcHEC

GFP Extension Header

GFP Payload

22220-60

AsClient

Bytes

PPP/HDLC Frame GFP-F Frame

ControlAddress

PPP Type

PPP Information

Pad



Ethernet to GFP-FramedEthernet to GFP-Framed

Up to 10MEthernet Stream

5M7.5M

10M

t1 2 3 4

2.5M

Pure Ethernet

GFP Packet Payload

Core Header

Constant Stream

Result

GFP-F Packet GFP-IDLE Packet

00hex00hex00hex00hex

Payload

cHECPLI 2

2

X

Scrambling!


GFP-Framed to VCGFP-Framed to VC

GFP-Framed Packet Stream

5M7.5M

10M

t1 2 3 4

2.5M

GFP Stream

VC-12 #5

VC-12 #4

VC-12 #3

VC-12 #2

VC-12 #1

GFP Framesin VC containers

Transport Thru the Network

Transport

Byte-Interleaving


Generic Frame ProcedureGeneric Frame Procedure

GFPBENEFITS

ReliableEasy & stabile algorithmHeader Correction

New Opportunities

Technological & Economical

Expandable with no need for

new transport equipment

Compatibleworks with basically any higher layer service and lower layer network!


OOthertherEEncapsulationncapsulation

MMethodsethods


HDLC, LAPS & GFP frameHDLC, LAPS & GFP frame

Flag(1byte)

Address.(1 byte)

Control.(1 byte)

CRC(4 byte)

Payload

HDLC

Flag(1byte)

Flag(1byte)

Address.(1 byte)

Control.(1 byte)

SAPI(1 byte)

CRC(4 byte)

Payload

LAPS

Flag(1byte)

SAPI(1 byte)

Core Header

(4byte)

Payload Header

(4 – 64 byte)

Client

payload

OptionalPayload FCS

(4 bye)

GFP - frame


HDLC, LAPS & GFP frameHDLC, LAPS & GFP frame

HDLC LAPS GFP

Advantages variable

frame length,

depending on

payload length

variable

frame length,

depending on

payload length

flexible for a large

number of services

simple and stable

synchronization

variable frame length

additional service

features e.g. multiplexing

Disadvantage

s

only Ethernet

and IP payload

unstable

synchronization

only Ethernet

and IP payload

unstable

synchronization

fairly large OH


GFP vs. LAPSGFP vs. LAPS

• GFP is more efficient thatn LAPS

constant overhead for any payload

allows easier traffic management and QoS control

• GFP is more robost than LAPS

single bit errors in the PLI & the cHEC does not cause loss of alignment

in LAPS a single bit error causes misalingment

• GFP minimizes system bandwidth requirements

allows multiple protocols to be transported via the same transport path

Allows multiplexing of several types of protocols on a frame by frame basis

• GFP supports RPR operation and is more suitable for packet traffic

new SONET/SDH functionalities like VC, LCAS work more efficiently with GFP


The EvolutionThe Evolution


““New SONET/SDH” - the evolution of SONET/SDHNew SONET/SDH” - the evolution of SONET/SDH

Ethernet

Ficon

Escon

Fibre Channel

SONET/SDH

MU

X/D

MU

X

Nat

ive

In

terf

aces

?GFP

Generic Frame

Procedure

LCAS

Link Capacity

Adjustment Scheme

VC

VirtualConcatination

Data Services - Ethernet, Fibre Channel & others GFP - frames the data & adapts the rates VC - offers right sized pipes in fine granularity LCAS - makes VC easy & flexible on demand

Result : SONET/SDH is flexible & data aware!


StandardsStandards


Standardisation (I)Standardisation (I)ITU-T• G.707/Y.1322 Network Node Interface for SDH

standardisation of Virtual Concatenation for high-order and low-order

definition of the H4 (for high-order path) and the K4 byte (for low order path) structure

• G.7041/Y.1303 Generic Frame Procedure standardisation of rate adaptation mechanism for different protocols e.g.

Ethernet, Fibre Channel, IP, etc. standardisation of two GFP modes e.g. transparent and frame-mapped

GFP

• G.7042/Y.1305 LCAS for Virtually Concatenated Signals • standardisation of dynamic bandwidth adaptation• Definition of hitless adding/removing of Virtual Containers


Standardisation (II)Standardisation (II)

• X.86 Ethernet over LAPS

describes the Ethernet mapping into SDH frames

analogy to HDLC/PPP framing

• X.85 IP over SDH using LAPS

describes the IP mapping into SDH frames

analogy to HDLC/PPP framing

IEEE

• Ethernet: 802.x

standardisation of various Ethernet types

definition of interface specifications


AbbreviationsAbbreviations


AbbreviationsAbbreviationsCC: Continguous

ConcatenationcHEC: Core Header Error CheckCRC: Cyclic Redundancy CheckEOF: End of FrameEoS: Ethernet over SONETESCON: Enterprise Systems

ConnectionFCS: Frame Check SequenceFD: Full DuplexFICON: Fibre ConnectionGFP: Generic Frame ProcedureGFP-F: Frame mapped GFPGFP-T: Transparent GFPGMPLS: Generalized Mulitprotocol

Label SwitchingIP: Internet ProtocolLAN: Local Area NetworkLAPS: Link Access Procedure SDHLCAS: Link Capacity Adjustment

SchemeMAC: Media Access Control

MAN: Metropolitan Area NetworkMFI: Multi Frame IndicatorMSOH: Multiplexer Section

OverheadNE: Network ElementOTN: Optical transport NetworkOSI: Open System InterconnectPDU: Protocol Data UnitPLI: PDU Length IndicatorPoS: Packet over SDH/SonetPPP: Point-to-Point ProtocolRSOH: Repeater Section

OverheadSAN: Storage Area Networks

SDH: Synchronous Digital Hierachy

TCP: Transport Control ProtocolTDM: Time Division MultiplexingVC: Virtual ConcatenationVC-xc: Virtual ContainerVCG: Virtual Container GroupWAN: Wide Area Network

overview of ng-sdh

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