Extending OTN Standards to Support Ethernet Services Maarten Vissers.

Extending OTN Standards to Support Ethernet Services

Maarten Vissers

Geneva, 27 May 2010 2

Disclaimer

This document complements liaison statement COM15 – LS140 It presents further details of

the Ethernet over OTN service application, a solution proposed for this application, a potential interoperability capability with existing 802.1Q (including amendments) edge nodes and networks

Objective of the liaison statement and this document is to collect feedback from IEEE 802.1 prior to progressing the work on a solution for this application in ITU-T SG15

Currently there is no agreed solution in ITU-T SG15


Introduction

Recently, Optical Transport Network (OTN) capabilities have been extended to make it flexible and feature richOTN is now a multi-service transport network supporting multitude of services:

any type of CBR service – including 1G, 10G, 40G and 100G (a)synchronous Ethernet streams ATM, Ethernet, MPLS, IP packet clients and Ethernet Private Line (EPL) services

Carriers demand extension of OTN standards to support Ethernet Private Tree (EPT), LAN (EPLAN) and Ethernet Virtual Private Line (EVPL), Tree (EVPT), LAN (EVPLAN) servicesWith the above services the OTN is able to interconnect two or more routers, Ethernet switches, PBNs, PBBNs, PBB-TENs, etc. (see )


IntroductionITU-T Q.9/15 and Q.11/15 received proposals for architecture and frame formats to support EPT, EPLAN, EVPL, EVPT and EVPLAN services in OTNThe proposals are based on the addition of a well defined ETH layer on top of the OTN Lower Order ODU layer

This ETH layer is referred to as Ethernet Virtual Channel (ETH VC) layer

Q.9/15 decided to liaise these proposals to 802.1 for review and feedback prior to progressing the work in Q9/15

NOTE – The definition of the ETH layer is based on IEEE Ethernet standards and extensively used in ITU recommendations

G.8010/G.8021/G.8031/G.8051. The ETH MEP, MIP, Connection and Protection functions and processes defined in these

recommendations are to be used without modifications. To be added is an ODU-to-ETH VC adaptation function.

NOTE – The definition of the ETH layer is based on IEEE Ethernet standards and extensively used in ITU recommendations

G.8010/G.8021/G.8031/G.8051. The ETH MEP, MIP, Connection and Protection functions and processes defined in these

recommendations are to be used without modifications. To be added is an ODU-to-ETH VC adaptation function.


Requirements

The proposals were used as a starting point for developing a set of requirements based on:

Service types to supportService encapsulation types to supportOTN architecture extensionETH VC encapsulation, identification and reserved address transparencyETH VC ManagementInteroperability with 802.1Q edge nodes and networks

The above items are addressed in subsequent slides


Service types

As a general principle, the OTN shouldaccept customer Ethernet service signals from any type of 802.3/802.1Q UNI or V-UNI

Untagged LANs, Priority-C-Tagged LANs, C-Tagged LANs, Priority-S-Tagged LANs, S-Tagged LANs, S+C-Tagged LANs, I-Tagged LANs and S+I-Tagged LANs.

support untagged, priority tagged, single tagged and double tagged ETH Characteristic Information (ETH_CI) service typessupport transparent, port-based, individual and bundled ETH_CI type servicessupport the 802.1Q defined ETH_CI service types

See for an illustration of those service types


Service encapsulationThe OTN should be able to accept the customer’s ETH_CI and

transport this ETH_CI without further encapsulation (peering mode)

transparent transport of the top N MEG OAM levels (e.g. MELs 7,6,5), the lower 8-N MEG OAM levels are used by the OTN

encapsulate this ETH_CI to preserve its VLAN or Service Identifier (VID/SID), Priority Code Point (PCP) and Drop Eligible Indicator (DEI) values present on the (V-)UNI (client/server mode)

transparently transfer the information in the C-, S- or I-Tag associated with the customer’s ETH_CI

encapsulate this ETH_CI within the payload of a new MAC frame

operator controlled option, beneficial in E-Tree/E-LAN service caseslimits the number of MAC Addresses to learn in a rmp or mp2mp ETH VC connection in the OTNcustomer’s ETH_CI frame – with or without its Tag on the (V-)UNI – will be prepended with a TYPE, SA and DA field

See for an illustration of those service encapsulations


OTN architectureextension

The OTN shouldsupport all service types by a single layer network

Restrict visibility of the different UNI interface presentations to the UNI-N ports

support the defined services by means of an additional Virtual Channel (VC) layer (see )transport the VC signals over LO ODUk connections which interconnect VC layer switching functions

The VC layer in the OTN shouldsupport p2p, p2mp, rmp and mp2mp VC connections to support the EVPL, E(V)PT and E(V)PLAN servicesbe an Ethernet (ETH) based VC layer networkdeploy Y.1731 Ethernet OAM to monitor the VC connection status and performancedeploy G.8031 Ethernet linear protection switching


VC encapsulation

The OTN should encapsulate each ETH VC frame in the same manner, independent of the

customer service supported by the ETH VCnumber of ETH VC signals (1 or n) carried in the LO ODUk connection

The encapsulation header should include fields to identify the

ETH VC to which the frame belongsif a single ETH VC signal is carried in the LO ODUk connection (private service case) the identifier field may be set to a default null value

priority and drop eligibility of the frame

See for an illustration of ETH VC frame encapsulation


VC identification

The OTN should support link local ETH VC connection identifiers

Default approach to support scalability of connections in a transport networkAllows for ETH VC ID interchange at link ends under control of ETH VC connection manager

identify frames of a (p2p, p2mp, rmp and mp2mp) ETH VC connection by means of a single identifier value per link

For the case of a “multi-root rooted-multipoint” ETH VC the use of a single identifier value per link might not be possible. Instead the use of two identifier values may be required. This is under study.


ETH VC managementand survivability

The OTN should manage (set up, modify, tear down, configure) the ETH VC connections and their MEP and MIP functions under control of NMS and/or ASON/GMPLSincrease survivability of the ETH VC connections by means of G.8031 ETH Sub-Network Connection (SNC) protection switching and/or GMPLS based ETH VC restoration

dual homing and/or dual node interconnect (DH/DNI) methods under development in Q.9/15 should be deployed to survive multiple faults


ETH VC Reserved Addresses transparency

The ETH VC switching functionality in the OTN may be represented by means of an “ETH VC Component”The “ETH VC Component” includes a MAC Relay, OTN Network Ports and optionally PB/PBB Facing Port(s)The “ETH VC Component”Reserved Address set should be minimized to provide maximum transparency for clientsThis minimal set is to be defined

ETH VCMAC Relay

PB, PBB Facing

Port

OTN Network

Port

Ethernet NNI

ETH VC Component

ODU_CI

OTN Network

Port

ODU_CI

ETH VC Network

Port


Universal Ethernet(V-)UNI-N port

It is an objective to specify a universal Ethernet UNI-N/V-UNI-N port which supports the set of EPT, EPLAN, EVPL, EVPT and EVPLAN servicesThis (V-)UNI-N port includes a (V-)UNI Facing Port, an ETH VC Network Port and a MAC Relay functionThis port should be configurable to support any service type

MAC Relay

(V-)UNI Facing

Port

UNI or V-UNI

(V-)UNI-N Port

ETH VC Network

Port

ETH VCMAC Relay


Interoperability with802.1Q edge nodes and networks

EVPL, EVPT and EVPLAN services supported by the OTN may have one or more of their UNI-N ports located outside the OTN

E.g. located in PEB, I-BEB, B-BEB, IB-BEB devices

The OTN should connect via an S- or I-Tagged LAN Ethernet NNI to those devices directly, or via an intermediate PB, PBB or PBB-TE network (see ) The ETH VC signal should in those cases be encapsulated with an S-Tag or I-Tag


ETH VC over PB, PBB, PBB-TE networks

Question: under which conditions can an ETH VC signal be transported through a PBN, PBBN and PBB-TEN?

In the OTN an ETH VC frame is combined with an ETH VC TagIf an ETH VC frame is combined with an S-Tag it looks like a S-VLAN and could then be transported through a PBN via a CNP on a PB or PEB nodeIf an ETH VC frame is combined with an S-Tag it looks like a S-VLAN and could then be transported through a PBB-TEN via a CNP on an IB-BEBIf an ETH VC frame is combined with an I-Tag it looks like a BSI and could then be transported through a PBBN via a CBP on a B-BEB or IB-BEB


ETH VC termination inPEB, I-BEB, B-BEB, IB-BEB, T-BEB

Question: under which conditions can an ETH VC signal be terminated in a PEB, I-BEB, IB-BEB or T-BEB?

ETH VC frames should be S- or I-Tagged as required by those nodesETH VC’s client signal should be a supported client signal of the node (see for an overview)


Summary

The addition of one ETH (VC) layer on top of the OTN’s LO ODU layer together with ETH switching functions in a subset of OTN cross connects enables the OTN to support EPT, EPLAN, EVPL, EVPT and EVPLAN services for any of the possible service types.A ETH VC Tag is required to mark each ETH VC frame within a LO ODU signal. It seems that this Tag can’t be one of the 802.1Q defined Tags.The Ethernet services may have a subset of their endpoints located outside the OTN, e.g. within 802.1Q defined nodes. Interoperability between the service layer in the OTN and the service layer in a PB, PBB and PBB-TE network and/or edge node is anticipated. Under which preconditions would this be possible?

Geneva, 27 May 2010

Backup


ETH_CI and ETH_AI

ETH Adapted Information (AI)

MAC_SDUEncapsulated clientOAM: APS, MCC, CSF

SADAPriorityDrop Eligible

ETH Characteristic Information (CI)

MAC_SDUEncapsulated clientOAM: APS, CSF, MCCOAM: CCM, AIS, LCK, LBx, LTx, TST, LMx, DMx

SADAPriorityDrop Eligible


Ethernet servicesover OTN examples

OTNS-Tagged

LAN

PBN S-Tagged LAN

PBNPB

I-Tagged LAN PBBNB-

BEB

S-Tagged LAN

PBN

PB

I-Tagged LAN

PBBN B-BEB

I-Tagged LANPBBN

B-BEB

C-Tagged LAN

.1QN

.1Q

C-Tagged LAN

.1QN

.1Q

C-Tagged LAN

.1QN.1Q

LAN

ETH VCC 2

ETH VCC 3

ETH

VC

C 1

ETH

VC

C 4

LAN

ETH VCC 5

ETH V

CC 6

PB

ETH VCC 7


Service typeson Ethernet UNIs/V-UNIs

UNI Link

UNI Link

EPL Type 2EPL Type 2/TT

EPL Type 1, EVPL Type 2EPT, EVPT Type 2

EPLAN, EVPLAN Type 2

EVPL Type 1/3EVPT Type 1/3

EVPLAN Type 1/3

EVPL Type 1/3EVPT Type 1/3

EVPLAN Type 1/3

UNI Link

ETH_CI service

ETH_CI service

ETH_CI service

UNI Link

UNI Link

UNI Link

UNI Link

Bit/CodeWord stream service

UNI Link

UNI Link

ETH_CI service

ETH_CI service

(V-)UNILink

ETH_CI service

Transparent servicePort based service

C-Tagged serviceS-Tagged serviceI-Tagged service

C-Tagged serviceI-Tagged service

S- + C-Tagged or S- + I-Tagged

ETH_CI

C-Tagged or S-Tagged or I-Tagged or B-Tagged

ETH_CI

UnTagged or Priority-Tagged ETH_CI

ETY_CI or ETH_CI service


Service encapsulationin Ethernet based VC layer

Ethernet VC layerEthernet VC layer

MSDUMSDU

DA/SA

MSDUMSDU

C-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

C-Tag

MSDUMSDU

I-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

I-Tag


Type 89-10

DA/SA

Type 89-10

DA/SA

MSDUMSDU

DA/SA

MSDUMSDU

C-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

C-Tag

MSDUMSDU

I-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

I-Tag

Type 89-10

DA/SA

Type 89-10

DA/SA

Type 89-10

DA/SA

Type 89-10

DA/SA

OAMOAM

DA/SATYPE 89-02

OAMOAM

DA/SATYPE 89-02

Encapsulated client information

Encapsulated client information

Y.1731G.8021G.8031G.8051

Y.1731G.8021G.8031G.8051

Sufficient encapsulation for P2P E-LINE and P2MP E-

Tree services supported by p2p and p2mp ETH VC

connections

Best encapsulation for RMP E-Tree and MP2MP E-LAN

services supported by rmp and mp2mp ETH VC

connections


OTN architecturewith additional ETH VC layer

Ethernet Virtual Channel layer (ETH VC)Ethernet Virtual Channel layer (ETH VC)

Customer Ethernet layerCustomer Ethernet layer

OCh layerOCh layerOCh layerOCh layer

UserNetwork

UserNetwork

LO ODU layerLO ODU layer

Ethernet-UNI Ethernet-UNI

VC Type IVC Type II

1:1 or n:1 1:1 or n:1

n:1

n:1

1:1

Eth Eth

Optical Transport Network

HO ODU layerHO ODU layer

OTU layerOTU layerOTU layerOTU layer

OTN transmission media layersOMSn+OTSn or OPSn or OPSMnkOTN transmission media layersOMSn+OTSn or OPSn or OPSMnk

UN

I specific EV

C

server layers

UN

I specific EV

C

server layers

EPTEPLAN

EVPLEVPTEVPLAN

Eth Eth

Additional VC layer


ETH VC encapsulationin OTN LO ODU layer

ETH VC frames are Tagged and then mapped into a GFP-F frameMAC FCS is appended to the GFP-F frameGFP-F frame is mapped into ODU payload areaGFP Idle frames are inserted in absence of ETH VC framesSee next slide for illustrations


Transmission Media

Transmission Media

ETH VC Tag + MAC FCS

GFP-F Header

WavelengthHO-ODUHO-ODU

LO-ODU

OTN A/GMP

OAMOAM

DA/SATYPE 89-02

ETH VC encapsulation headers/trailers


MSDUMSDU

DA/SA

MSDUMSDU

C-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

C-Tag

MSDUMSDU

I-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

I-Tag OAMOAM

DA/SA

TYPE 89-02

Encapsulated ETH VC information

Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag

GFP Header GFP Header GFP Header GFP Header GFP Header GFP Header GFP Header

MAC FCS

MAC FCS MAC FCSMAC FCS

MAC FCSMAC FCS

MAC FCS

One tag for all

Eth VC Tag can not be a C-Tag, S-Tag or I-Tag

Eth VC Tag should be a new Tag

ETH VC encapsulation

Type 89-10

DA/SA

Type 89-10

DA/SA

MSDUMSDU

DA/SA

MSDUMSDU

C-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

C-Tag

MSDUMSDU

I-Tag

DA/SA

MSDUMSDU

S-Tag

DA/SA

I-Tag

Type 89-10

DA/SA

Type 89-10

DA/SA

Type 89-10

DA/SA

Type 89-10

DA/SA

OAMOAM

DA/SA

TYPE 89-02

Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag Eth VC Tag

EncapsulatedETH VC information

GFP Header GFP Header GFP Header GFP Header GFP Header GFP Header GFP Header

MAC FCS

MAC FCS MAC FCSMAC FCS

MAC FCSMAC FCS

MAC FCS

One tag for all


OTNEth VC Tag

Universal Eth UNI

Universal Eth UNI

OTM-0 withETH VCs

Universal Eth UNI

EOTN XC

EO

TN

XC

= BCBPB

EOTN

EOTN

OTN

EOTNOTN

OTN

EOTNNT

I-Tagged ETH VCs

Eth UNI

I-BEBG

PEB

S-Tagged ETH VCs

Eth UNI

H PTNNT

ETM-n withETH VCs

Universal Eth UNI

I

J

K

L

IB-BEBTE

Eth UNI

S-Tagged ETH VCs

PTNNT

ETM-n withS-Tagged ETH VCs

Universal Eth UNI IB-BEB

TE

IB-BEBTE

BCBTE

PBB-TEN

MN

S-Tagged ETH VCs

PEB

PBN

S-Tagged ETH VCs

Eth UNI

PTNNT

ETM-n withS-Tagged ETH VCs

Universal Eth UNI

PB

PB PB

PB

E

F

PBBN

I-Tagged ETH VCs

I-Tagged ETH VCs

Eth UNI

PTNNT

ETM-n withI-Tagged ETH VCsUniversal

Eth UNI

B-BEB

B-BEB

B-BEBBCB

B-BEBT-BEB

Eth UNI

I-BEB

A

B

CEth UNI

D EOTN

EOTN

EOTN

EOTN

EOTNEOTN


Node type

UNI-N Port type

Service type UNI or V-UNI Tagging

Un CP C SP S S(c) I S(i) [s]C [s]I

PEB CNP 1:1 Port-based X X X X - - - - - -

1:1 S-Tagged - - - - X X - X - -

CEP+PEP+CNP 1:1, n:1 C-Tagged X X X - - - - - - -

I-BEB CNP+PIP 1:1 Port-based X X X X - X - X - -

1:1, n:1 S-Tagged - - - - X X - X - -

B-BEB CBP 1:1 I-Tagged - - - - - - X - - -

T-BEB CNP-T+PIP 1:1 Transparent X X X X X X - X - -

IB-BEB TE CNP+PIP TE 1:1 Port-based X X X X - - - - - -

1:1 S-Tagged - - - - X X - X - -

PTN NTEOTN NT

Universal (V-)UNI-N

1:1 Transparent X X X X X X X X - -

1:1 Port-based X X X X X X X X - -

1:1, n:1 S-Tagged - - - X X X - X - -

1:1, n:1 C-Tagged1:1, n:1 I-Tagged

X X X - - - X - X X

Un: Untagged, CP: C-Priority-Tagged, C: C-Tagged, SP: S-Priority-Tagged, S(c): S+C-Tagged, I: I-Tagged, S(i): S+I-Tagged, [s]C: S+C-Tagged with S-Tag terminated and C-Tagged instance taken as service, [s]I: S+I-Tagged with S-Tag terminated and I-Tagged instance taken as service1:1: individual service, n:1: bundled service

Service typessupported by node/port type

Extending OTN Standards to Support Ethernet Services Maarten Vissers.

Documents

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eth vc frame

otn customers eth

defined eth layer

bundled eth

eth mep

otn service application

mp2mp eth vc connection