otn overview & update jean-marie vilain product specialist

OTN Overview & Update

Jean-Marie VilainProduct Specialist

2© 2010 EXFO Inc. All rights reserved.© 2010 EXFO Inc. All rights reserved.

AgendaAgenda


SONET-SDH structureSONET-SDH structure

Sonet / SDH technologies have been out for a while now, the main goal was to Sonet / SDH technologies have been out for a while now, the main goal was to transport digital information over fiber, but also support electrical lower rate transport digital information over fiber, but also support electrical lower rate communication signalcommunication signal

payloadoverhead

payloadoverhead



SONET / SDH supported transport rateSONET / SDH supported transport rate



VCAT/LCASVCAT/LCAS

VCAT/LCAS and GFP offeredAutomatic Flexible bandwidth andClear way to map Ethernet traffic In to Sonet


Virtual Concatenation Bandwidth EfficiencyVirtual Concatenation Bandwidth Efficiency

ContiguousConcatenation

Virtual ConcatenationService Data Rate

SONET SDH

Effici-ency

SONET SDH

Effici-ency

Ethernet 10Mb/s STS-1 VC-3 20% VT-1.5-7v VC-12-5v ~90%ATM 25Mb/s STS-1 VC-3 50% VT-1.5-16v VC-12-12v 98%Fast Ethernet 100Mb/s STS-3c VC-4 67% STS-1-2v VC-3-2v 100%Fiber Channel 200Mb/s STS-12c VC-4-4c 33% STS-1-4v VC-3-4v 100%Gbit Ethernet 1000Mb/s STS-48c VC-4-16c 42% STS-1-21v VC-4-7v 95%

EfficiencyIncrease

67%100%


GFPGFP

VCAT/LCASVCAT/LCASEthernet map into SDH/SONETUsing GFP


WDM TransmissionWDM Transmission

ADMADMDXC

ADM ADM

ADM

ADM

ADM

ADMADM

ADM

WDM line systemfor fiber saving

WDM fiber WDM

WDMWDM fiberWDM

WDM

Services Layer

Delivery of services to

end customers.

SDH/SONET Layer

High-speed protection/restoration.

Time division multiplexing

Optical layer

Wavelength division multiplexing

High level protection

WDM line system


Why OTNWhy OTN

ITU G.709 is the OTN Standard

ITU G.709 is the OTN Standard


Why OTNWhy OTN


OTN mapping structureOTN mapping structure


OTN Frame FormatOTN Frame Format


OTN Overhead structureOTN Overhead structure

The FAS/MFAS provides frame alignment.

The FAS/MFAS provides frame alignment.

The Section Monitoring provides Error detection and

communication

The Section Monitoring provides Error detection and

communicationThe ODU overhead brings TCM support, Communication channels and Automatic

protection switching

The ODU overhead brings TCM support, Communication channels and Automatic

protection switching

The OPU overhead adapt the client signal to the optical

channel, specifying the type of client signal in the payload

The OPU overhead adapt the client signal to the optical

channel, specifying the type of client signal in the payload


Why the use of OTN over SONET/SDHWhy the use of OTN over SONET/SDH

OTN provide better TCM support

Over-multiple

Carriers.

SDH/SONET only support one TCM vs.

6 TCM for OTN

SDH/SONET only support one TCM vs.

6 TCM for OTN


› FEC provides the following benefits.

› Improves the BER performance of an existing link › Increases the maximum span of a link can extend up to 20km and remove the

need of regenerator › Improves the overall quality of the link by diagnosing link problems earlier

Forward Error Correction (FEC)Forward Error Correction (FEC)


ITU G.709 Sup 43 Over-Clocked OTN rates OTU1e – OTU2eITU G.709 Sup 43 Over-Clocked OTN rates OTU1e – OTU2e

The goal here, is to combine multiple 10GE ports from the Core router directly into OTN.

Not to be confused with OTU1 which is a 2.7 Gbit/s signal, these are 10G ratesNot a big issue with 10GE Wan (9.953 Gb/s) where the signal can be directly map into an OPU2 containerThis is more a problem with the 10GBASE-R 10GE LAN, where there’s a size mismatch between the containers.


Ethernet in Carrier Networks EoOTNEthernet in Carrier Networks EoOTN

ODU1 mux in ODU2

OTU2 , OTU3 or even OTU4

OTU1

ODU MUX

1GigE in ODU0 in OTU1

Access Routers

Access Routers

Access Routers

OTU2

OTU1 with ODU0

OTU2

10/100M Ethernet link

GigE link

OTU1

Access Network

ENIU

MSPP

MSPP


Client Interface cardsClient Interface cards

Transponder cards • Proper provisioning• Power levels• Bit Error Rate tests• FEC (OTN)

100M/GbE

10GbE

FC

SONET/SDH

10.7G OTN

(G.709)

DWDM

& OLA

Powerful

• Unframed/ frame testing

• SONET/SDH (10G)

• OTN (OTU1/2/1e/2e) with FEC

• 10/100/1000BaseT, Gig-E & 10G Ethernet

• 1x/2x/4x/10x FC

8130NGE


• ODU0 is a new container size that has been introduced in the G.709 to accommodate efficient transport of Gigabit Ethernet (1.25 Gb/s). OTU1 was not efficient for 1GbE signal with a payload rate of 2.48832Gb/s

• ODU0 is half the size of an ODU1 container i.e = 1.244 160 Gb/s

• Gigabit Ethernet does not fit in the OPU0 payload, GMP will be use to insert the Gigabit Ethernet rate inside OPU0 rate

Note: ODU0 does not have a physical instance (i.e. there is no OTU0), the signal needs to be multiplexed into a higher layer in order to be transported on the OTN network

New ODU 0 OTN containerNew ODU 0 OTN container


› ODU0

› New multiplexing method1 that allows direct ODU0 multiplexing into ODUk (k=2,3,4) in a single stage

• This multiplexer uses Generic Mapping Procedure (GMP) for ODU0 justification control

• Where GMP will support various client signals and future new ones. It is a generic procedure for mapping a client signal with any bit rate less than the payload capacity to the ODU.

New ODU 0 OTN containerNew ODU 0 OTN container


› ODU0 mapping?

› The mapping of a ODU0 into a ODU1 is done using ODTU01 (optical channel data unit tributary ) where the ODU1 structure is divided into two sections and where both ODU0 are map. Each needed ODU0 are mapped in to the payload using GMP to specific timeslot.

Technology Overview Technology Overview ODU ODU


› Any client signal can be map into the payload using the below process, where each low order signal will mux into a timeslot and be insert in to the payload

Technology Overview Technology Overview


› ODUflex is a new OTN variable container introduce in October 2009› Allows for flexible ODU rates for transparent transport of any client

signal, it used a similar process to VCAT except that there is no delay because the signal is map in to the same physical container

› Adapted in 2 ways:o For Constant Bit Rate (CBR)client signals

Rate = 239/238 x CBR rateo For GFP-F mapped packet client signals

Rate = N x ~1.25Gbit/s (ODU0) with 1 ≤ N ≤ 80

ODUflexODUflex


40GE/100GE Mapping into OTN 40GE/100GE Mapping into OTN

› Wide-area Ethernet transport technologies are necessary to support, for example, the connection of Ethernet switches separated by more than 40 km (typical distance supported by Ethernet standards).

› ITU-T SG15 is responsible for OTN standardization and IEEE 802.3ba is responsible for 40G/100G Ethernet standardization; both working closely to develop 40GE/100G transport capability over OTN


40GE/100GE Mapping into OTN 40GE/100GE Mapping into OTN

› Standard 40GE runs at 41.25Gbps and OPU3 payload is only 40.15 Gbps

› Therefore, mapping 40GE over OTU3 requires 1024/1027B transcoding adaptation to reduce 40GE coded rate

OH

Using 1024B/1027B

40.117G

40.15052GODU3

40.319G

GMP

OH

103.125G

104.355G

GMP

1x 1x

OTU4

ODU4104.794G

100GE

1x 1x

OTU3

40GE

41.25G40GE with 64B/66B Transcoding


1.1. OTN OTL (OTU3/OTU4) OTN OTL (OTU3/OTU4)

Client Client

OCh Payload Unit (OPU) PayloadOCh Payload Unit (OPU) PayloadOPU OH

OPU OH

OCh Data Unit (ODU) PayloadOCh Data Unit (ODU) PayloadODUOH

ODUOH

OCh Transport Unit (OTU) PayloadOCh Transport Unit (OTU) PayloadOTU OH

OTU OH FECFEC

OTLk.nOTLk.n OTLk.nOTLk.n OTLk.nOTLk.n

1 2 n

OTL type & bit rateOTL3.4 = 10.7Gb/s OTL4.4 = 27 95Gb/s OTL4.10 = 11.18Gb/s

OTUk & bit rateOTU3 = 43Gb/s OTU4 = 112Gb/s

OTUk signal is transmitted over n lanesOTUk signal is transmitted over n lanes

NewNew


Traditional OTN StructureTraditional OTN Structure


New OTN StructureNew OTN Structure

otn overview & update jean-marie vilain product specialist

Documents

otn slide

sonet slide

otn standard slide

payload slide

gfp slide

agenda slide

otn mapping structure

otn frame format slide