ITU - Telecommunication Standardization Sector                                     Working Document 11-R2

STUDY GROUP 15

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Milan, 06-08 February 02

Questions:   11/15 (+ Q.9, 12, 14, 16 & 19)

SOURCE:    Rapporteur FOR Q.11/15

TITLE:          REPORT OF THE MILAN EXPERTS MEETING (06-08/02/02)

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1 - Introduction

             Within ITU-T SG 15, Q.11 deals with "Signal structures, interfaces and interworking for transport networks".

             During the October meeting of Q.11/15, Lucent Technologies (refer to D.301 to 304 - Oct. 01) presented the concept of the so called "Virtual Backplane Interface (VBI)". They proposed that this new interface is standardized by SG 15 in order to allow the interconnection, in a multi-vendor environment, of optical line interfaces and a distant photonic matrix fabric. It was agreed to hold an experts meeting dedicated to VBI in order to progress the discussion on the subject.

             That meeting was held in MILAN (Italy) from the 6th (PM) to the 8th (AM) of February 02, at the kind invitation of Alcatel.

             The meeting chaired by the Q.11 Rapporteur (G. JONCOUR, France Telecom), was attended by 26 representatives (see Annex 1) during the first session and by 15 to 20 persons during the rest of the meeting.

             The list of the Working Documents examined during the meeting is reproduced in Annex 2. An electronic copy of each of them can be found at: http://ties.itu.int/u/tsg15/sg15/wp3/q11/0202.

             The main results of the discussions held during the meeting are reported below.

2 – Results

             WD 3, submitted jointly by AT&T, Ciena and Sprint, supported the concept behind OLI or VBI. It attempted to identify the issues associated to it and proposed a way to move forward, if agreed, in the standardization process of the VBI by SG 15.

             WD 4 (Worldom and Nayna Networks), WD 8, 9 and 10 (Lucent Technologies) presented equipment configurations and applications that motivate the need for the definition of a VBI.

             In WD 1, Marconi indicated that they do not believe that there is a need to create standards for a new interface. Orally, they recommended that, at a minimum, the physical interface to be used to carry the VBI logical information is selected amongst the already existing ones ; i.e. that the work on VBI does not result in the definition of any new physical interface.

             WD 2 contained the report of the SG 15 Representative to IETF CCAMP (W. ALANQAR, Sprint) on the most recent activity held within that Working Group and the IPO one. WD 2 contained a few information regarding the OLI (Optical Link Interface) and LMP (Link Management Protocol). Delegates mentioned that the results of the work on LMP should be considered when selecting the protocol to be run over the VBI. The rest (updated after the March 02 meeting of the IETF) of the document will be considered by Q.11 during the next meeting of SG 15 (April-May 02).

             WDs 6 and 7, from Lucent, were companion contributions to respectively WD 9 and 10. Already discussed by Q.12, they were not presented during the meeting.

             The discussion that followed the presentation of the documents mentioned above showed that the term VBI and even its original definition were not anymore relevant, in particular the VBI does not transport payload traffic. This led to the identification of a new concept : the Detector-Controller Interface (DCI). The following definition of the DCI has been adopted:

The Detector-Controller Interface (DCI) is an interface between a component representing the control view of the anomalies detector state (TAP) in one NE and a control function in another NE. The currently identified information flowing across such an interface is the trail/link status (such as SD, SF, idle, OK, message grouping) and connection state (such as in service or out of service).

             The purpose of the DCI is to carry information related to the detection of anomalies in a network element to another one in which actions have to be taken consequently. The DCI is therefore considered as a means to notify states between 2 different NEs.

             The intention of the DCI is to allow NEs from multiple vendors to cooperate to perform a network function such as protection or restoration.

The rest of the meeting was devoted to exchanging information between the experts with the view to get a shared understanding of the DCI and eventually help to determine if it represents a valid study item for SG 15.

             Annex 3 contains the results of that work. It includes illustrations of the so far identified configurations/applications for which the use of a DCI is applicable. It also identifies the issues that may need to be addressed if SG 15 decides to go for its standardization. It finally proposes an allocation of work amongst various questions of the Study Group.

             It was felt worthwhile to inform IETF CCAMP and the OIF Signalling and architecture Working Groups of the results obtained during the meeting. A communication to these groups has been prepared (see Annex 4).

3 - Future work

             The next meeting of Q.11 will be held during the next meeting of SG 15 (29/04/02 to 10/05/02 in Geneva).

             Q.11 proposes that the herein contained information is forwarded to all the possibly involved other Questions of SG 15 in order to take a decision as regards its standardization. Contributions on DCI are therefore requested. They should, in particular, allow the identification of the areas for which a specific effort is consequently needed.

             Q.11/15 experts felt that the DCI issues should now be progressed under Q.12/15 from an architecture and applications point of view, such as restoration/protection, etc.

             All the interested people are encouraged to submit contributions to that Question.

- Annex 1 -

List of participants

 

 

Name

Company

Country

 

J-L. FERRANT

Alcatel

France

 

D. BELLER

Alcatel

Germany

 

V. HŽGELE

Alcatel

Germany

 

A. BELLATO

Alcatel

Italy

 

S. BELLOTI

Alcatel

Italy

 

V. MIRIELLO

Alcatel

Italy

 

m. sluyski

AMCC

USA

 

D. BRUNGARD

AT&T

USA

 

M. LAZER

AT&T

USA

 

S. BINETTI

Cisco

Italy

 

G. JONCOUR

FT

France

 

Y. LE LOUEDEC

FT

France

 

M. HANDLEY

Fujitsu

UK

 

M. VISSERS

Lucent Technologies

NL

 

C. DALOIA

Lucent Technologies

USA

 

G. NEWSOME

Lucent Technologies

USA

 

S. SANKARANARAYANAN

Lucent Technologies

USA

 

G. ABBAS

Marconi

UK

 

M. BETTS

Nortel

Canada

 

L. PRATTICO

Nortel

USA

 

M. MAYER

Nortel

USA

 

N. NAGATSU

NTT

Japan

 

J. HEILES

Siemens

Germany

 

W. TELLER

Tellabs

USA

 

C. BROWNMILLER

Worldcom

USA

 

J. GAMBONY

Worldcom

USA

- Annex 2 -

Documentation for the meeting

 

WD nø

Title

Source

1

VBI standardisation

Marconi

  2 *

Report on IETF IPO and CCAMP meeting, 10-14 Dec. 01

SG 15 Represent. to IETF CCAMP

  3 *

OLI/VBI standardization strategy

AT&T, Ciena, Sprint

  4 *

An example application in support of VBI

WorldCom, Nayna Networks

5

Agenda and documentation for the meeting

Rapporteur Q.11/15

  6 *

Link Restoration Application

Lucent Technologies

  7 *

Application of provisioning monitors along a connection

Lucent Technologies

  8 *

Functional models of equipment configurations

Lucent Technologies

  9 *

Link restoration control interfaces (Internal and external)

Lucent Technologies

  10 *

Monitor provisioning control interfaces (Internal and external)

Lucent Technologies

11

Report of the meeting

Rapporteur Q.11/15

* Also submitted to Q.12 (Milan, 04-06/02/02)

- Annex 3 -

The Detector-Controller Interface (DCI) concept

 

I - Definition

             The Detector-Controller Interface (DCI) is an interface between a component representing the control view of the anomalies detector state (TAP) in one NE and a control function in another NE. The currently identified information flowing across such an interface is the trail/link status (such as SD, SF, idle, OK, message grouping) and connection state (such as in service or out of service).

II - Related configurations/applications

 

 

 

 

 

 

 

 


CF = Control Function - NE = Network Element

Figure 1a - General configuration (showing 3 NEs)

 

 

 

 

 

 


Figure 1b - G.805 view (showing 6 NEs)

 

 

 

 

 

 

 

 

 

 

 


Figure 2a – Link/trail state notification (Case 1)

 

 

 

 

 

 

 

 

 

 

 

 


Figure 2b – Link/trail state notification (Case 2)

 

 

 

 

 

 

 

 

 

 

 

 


Figure 3a – Connection state notification (Case 1)

 

 

 

 

 

 

 

 

 

 

 

 


Figure 3b – Connection state notification (Case 2)

 

III - Associated issues

             The following items have been identified as potentially needing to be addressed when standardizing the DCI:

ú         Information, parameters to be transferred

ú         Information format/coding

ú         Transfer bitrate

ú         Protocol

ú         Information/message latency

ú         Reliability/resilience of the information

ú         Physical interface

             In addition to the implementation of a DCI between the 2 NE containing the detectors and the control function, the fact that these NEs are implemented and interconnected in conformance with others standards is also essential to their global interoperability.

IV - Questions of SG 15 to be involved in the standardization process:

             The opinion of Q.11 is that the following experts should be involved in the standardization of the DCI:

ú         Q.12 : study the applications/architectures of this DCI

ú         Q.14 : identify the information to be carried over the DCI

ú         Q.11 : define the logical interface of the DCI

ú         Q.9 : address equipment aspects related to DCI

ú         Q.16 : develop, if found necessary, a new physical interface for supporting the DCI

ú         Q.19 : insure the coordination between the above questions

 

- Annex 4 -

Communication to IETF CCAMP WG and OIF Signalling and Architecture WGs

 

 

QUESTIONS:      Q.11/15

SOURCE:           ITU-T Study Group 15

TITLE:                 Detector-Controller Interface (DCI)

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COMMUNICATION STATEMENT

TO:               IETF CCAMP Working Group and OIF Signalling and Architecture WGs

APPROVAL: Q.11/15

FOR:            Information and comment

DEADLINE:   15th April 02

CONTACT:    Gilles JONCOUR                            Tel:       +33 2 96 05 24 69

                                                                        Fax:      +33 2 96 05 12 52

                                                                        Email:   gilles.joncour@francetelecom.com

               

             Q.11/15 met in Milan (Italy) from the 6th to the 8th o February 02, with the mandate to further discuss the subject of Virtual Backplane Interface (VBI) which had been introduced during the previous meeting of SG 15 (Geneva, Oct. 01).

             Please find attached the report of the meeting. We would be interested in receiving any comment you may have regarding what we now call the "Detector-Controller Interface (DCI)".

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