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Re: OLI/LMP-WDM/NTIP => next step in ITU-T SG15
TO: CCAMP, T1X1.5
Here is a first feedback related to the introduction of the Virtual Backplane
Interface (VBI) issue in ITU-T SG15.
I have introduced the series of 4 VBI contributions during the SG15 meeting in
October. As a result of the introduction and associated off-line discussions, I
created a proposed work programme which you find in the forwarded VBI email
It was agreed to continue the discussion on the work programme for the VBI topic
on the Q.19/15 mailing list. I initiated this discussion on Oct. 25 via the
email you find below.
So far, none of the organisations in ITU-T SG15 has responded on the email. This
may imply that there is no need/support for standardisation of such VBI; the VBI
might be viewed as an internal equipment interface (of which standardisation is
outside the scope of ITU-T).
I will try to reach a conclusion on this VBI topic in ITU-T SG15 by the end of
this month, to support further decision making on the related OLI/LMP-WDM topic
in IETF/CCAMP in the IETF52 meeting in December.
=============== begin of forwarded VBI email ======================
-------- Original Message --------
Subject: work programme for VBI (virtual backplane interface)
Date: Thu, 25 Oct 2001 00:41:02 +0200
From: Maarten Vissers <email@example.com>
Reply-To: Maarten Vissers <firstname.lastname@example.org>
Organization: Lucent Technologies
To: q19/15 <email@example.com>
To: Q.9/15, Q.11/15, Q.13/15, Q.14/15, Q.16/15, Q.17/15 and Q.19/15
|Please reply to this email via Q.19/15 email mailing list only|
Last week I introduced contributions D.301, D.302, D.303 and D.304 to Q.9/15,
Q.11/15, Q.12/15 and Q.14/15.
These contributions introduce a new interface, referred to as "Virtual Backplane
Interface". They are the result of a new equipment paradigm as described in
This VBI is the interface between the tributary port of an OLS (optical line
system) and the port on an optical fabric equipment (photonic cross connect).
This interface consists of a number of optical interfaces carrying traffic
signals (e.g. wavelengths) and a supervisory interface (called: VBI funiculus).
These contributions describe the architectural aspects, the applications, the
physical aspects and performance aspects associated with this VBI. They propose
to start a new work item in SG15 to define this VBI.
Having had a further look into the work to be done, it seems that the following
questions will be involved in a development of a VBI specification: Q.9/15,
Q.11/15, Q.13/15, Q.14/15, Q.16/15, Q.17/15 and Q.19/15. And we should not
forget the network management aspects, which implies that one or more questions
in SG4 will most likely be involved (to be identified).
A first break down of work is presented below:
Q.9/15 equipment model/specification (specify atomic functions),
definition of SDH/OTN ports, port management parameter lists
Q.11/15 interface specification, including definition of primitives to pass
over VBI funiculus to support the identified applications (input
Q.13/15 jitter/wander aspects for VBI data interfaces
Q.14/15 VBI funiculus protocol aspects, including the coding of primitives
into actual protocol messages; also associated equipment management
Q.16/15 specification of "connection characteristics" of the combination of
"fiber - optical fabric - fiber connection" to support all optical
signals to be cross connected/switched
Note: the specification for the case of 3R points being present in
the OLS tributary ports is already present in G.693
Q.17/15 characterisation of optical switch components to support Q.16/15 work;
e.g. cross talk in optical switch
Q.19/15 create, coordinate and track VBI work programme, coordination with
IETF and OIF groups working in same area
in addition SG4 will have to have a closer look into the network management
aspects of these multi-vendor subnetworks and multi-vendor optical cross
While OLS equipment is already in the networks and PXC equipment is being added,
there is an urgency to start and progress this new VBI development. I foresee a
series of VBI recommendations (G.vbi.1, G.vbi.2, ...) to be created to support
this work. The work should initially be done via correspondence aiming at major
decisions to be made in the April/May 2002 SG15 meeting such that vendors can
start implementing this VBI on their products. Approval of the VBI
recommendations should be targeted for the Jan/Feb. 2003 SG15 meeting.
It hasn't become clear how many (operator, vendor) organisations are supporting
this new equipment paradigm. So far I have heard the following:
A) support new equipment paradigm: will obtain WDM line ports (i.e. OLS) and
optical fabric equipment (PXC) from multiple vendors and integrate those line
ports and fabric myself.
B) do not support new equipment paradigm: will obtain WDM line ports and optical
fabric from one vendor (vendor may OEM WDM line ports and/or optical fabric from
third parties and integrate those).
C) if VBI comes alive, we may extend it to SDH in order to resolve the MS SPring
interworking issue when the ring contains DXCs and ADMs of multiple vendors.
D) have to work the VBI issue under all conditions; either as proprietary
backplane interface, or as standardised virtual backplane interface.
E) we haven't been able to manage equipment of different vendors within one
subnetwork so far, now we should be able to manage line ports and fabrics from
To get an understanding of the level of support, I would like to invite you to
indicate if your organisation intents to support the new equipment paradigm and
supports the proposed new VBI work. In case of sufficient support, the work
programme details can then be discussed.
PS. In order to prevent this VBI work programme discussion to flood our email
boxes, it is proposed to only use the Q.19/15 mailing list. For that reason I
have used "Bcc:" to send this email to Q.9, Q.11, Q.13, Q.14, Q.16 and Q.17
mailing lists, expecting that a reply all will only go to Q.19/15.
If you are not yet subscribed and would like to participate in the discussion of
this work programme please subscribe via the EDH mailing list page:
The email list archive for Q.19/15 can be found at:
==================== end of forwarded VBI email ======================
Maarten Vissers wrote:
> I am pleased to announce the availability of 4 contributions for the upcoming
> SG15 meeting addressing the rationale/architecture, applications, physical and
> performance aspects of the interface between an OLS and an PXC.
> These contributions resulted from interaction with key players(*) in the IETF
> ccamp WG concerning the OLI, LMP-WDM and NTIP activities.
> (*) Osama Aboul-Magd, Curtis Brownmiller, John Drake, Andre Fredette
> and Jonathan Lang
> You will find the contributions (in word97 and pdf formats) in
> This interface is referred to by many names so far: LMP-WDM, OLI, NTIP, OTM-LF.
> In the contributions, it is referred to as Virtual Backplane Interface (VBI),
> but a better name is urgently needed...
> This interface is a true transport plane interface and once standardized by
> ITU-T SG15 it should be usable for the purposes needed by ITU-T/T1, IETF ccamp
> WG and OIF.
> Please review the contributions and provide comment either during the upcoming
> SG15 meeting in Geneva (Oct. 15-26) or via correspondence. These contributions
> are intended to provide a framework for the new interface specification. The
> specification work itself is obviously the next step and a united ITU-T/T1/IETF
> CCAMP/OIF effort to progress this specification would be an excellent way
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