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COM 15 – LS 11 – E

/ INTERNATIONAL TELECOMMUNICATION UNION / COM 15 – LS 11 – E
TELECOMMUNICATION
STANDARDIZATION SECTOR
STUDY PERIOD 2005-2008
English only
Original: English
Question(s): / 14/15 / Geneva, 29 November – 3 December 2004
LIAISON STATEMENT
Source: / ITU-T SG15
Title: / Response to IETF CCAMP WG on Comparison of LMP and ASON Discovery
To: / IETF CCAMP WG and Routing Area Directors
Approval: / Agreed to at SG15 meeting (Geneva, 29 November – 3 December 2004)
For: / Action
Deadline: / 15 March 2005
Contact: / Hing-Kam Lam
Lucent Technologies
USA / Tel: +1 732-949-8338
Fax: +1 732-949-1196
Email:

Q14/15 thanks the IETF CCAMP WG for providing us the draft document <draft-ietf-ccamp-transport-lmp-00.txt>. This I-D was discussed at the meeting and several of the comments are provided below. Based upon this discussion we believe it would be highly beneficial to have some joint discussions on terminology to ensure an aligned view to facilitate our future work efforts.

We have several questions of clarification, e.g., in section 3.1 (paragraph 2) of the I-D, “The separation between the two processes and corresponding two name spaces has the advantage that the discovery of the transport plane can be performed independent from that of the control plane (and vice-versa), and independent of the method used in each name space. This allows assigning link connections in the control plane without the link connection being physically connected.”

  1. What is the intention of the term independent, for example, could it be indicating at a different time or different approaches?
  2. In the last sentence, is “assign” used in the context of the management plane, meaning management plane provisioning? Is it assumed that the transport plane resources supporting the link connection endpoints exist or do not exist?

In section 4.2 (paragraph 2) of the I-D, “G.8080 refers to a component link as a variable adaptation function i.e. a single server layer trail dynamically supporting different multiplexing structures.” This could be interpreted as indicating G.8080 defines the term “component link”. G.8080 does not use this term. Some clarification would be beneficial.

Initial reviews of the draft document have raised concerns about the possible misinterpretation in the usage of the term ‘TE link’. As the draft notes, the definition of a TE link is concise. Some more clarity would be appreciated. Our current understanding of this term includes the following:

  1. A TE link may be composed of resource from multiple (G.805) layers in parallel. If so, this is an important distinction as an SNPP link is in a single layer only.
  2. An SNPP link may contain SNP link connections from various links (e.g., different STS-1s from a set of parallel OC -48 trails). It is not clear if this is also true for TE links. We think it may, but it is not stated.
  3. SNPPs exist at different routing levels (not layers) and thus an SNPP link at a higher level can encompass SNPPs at a lower level (see Section 6.2.2 of G.8080 Amendment 2, which is attached for your convenience). We think TE links may do this with bundles and FAs, but the definition is not clear to us.

Please advise if this is a correct understanding or not. This may have an impact on the terminology mapping in the draft. We think it would be beneficial to have a TE link definition that enables these distinctions to be understood.

In the table in section 4.2 “CP” is mapped to “Interface”. A Connection Point is more closely related to a timeslot, wavelength, etc. rather than to an entire interface. Similarly “CP Name” is mapped to “Interface ID” while it might more closely relate to a “Label”. Joint discussion of the terminology mapping may be beneficial in reaching alignment on the most accurate mapping.

As noted above, these represent several of the comments discussed. In order to progress our mutual understanding, we would like to invite IETF participants to attend the January 24-28, 2005 Q14/15 interim meeting, in New Jersey, USA, where we could devote a session to terminology alignment. We believe this effort will greatly benefit our future collaboration on control plane standards development. We welcome IETF experts’ participation in other sessions of the interim meeting as well. Details of the meeting agenda will be provided prior to the meeting. For those interested in further information and/or attending the interim meeting should contact the Rapporteur for Q.14/15 (H. Kam Lam, ) by 10th January 2005.

An electronic copy of this liaison and the attachments can be found at

ftp://sg15opticalt:/tsg15opticaltransport/COMMUNICATIONS/index.html >

Attachment: Editor’s draft of G.8080 incorporating Amendment 2

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M:\SG_DOC\SG15\2005-2008\LS\Outgoing\2004-11\COM15-LS011.doc