IP over Packet Transport Rings (IPoPTR) BOF
Minutes, IPoPTR BOF Meeting, IETF-48, Pittsburgh, PA
Friday, August 4th, 2000, 9:00-11:30 am
Chairs: Albert Herrera, Raj Sharma
The following agenda was presented and accepted:
1. Agenda Bashing (5 min.)
2. BOF Scope and Objectives (10 min.)
3. Packet Transport Rings Concepts and Requirements (45 min.)
4. Status of IEEE related activities (20 min.)
5. Proposed Charter (5 min.)
6. Charter Bashing (15 min.)
7. Goals & Milestones (10 min.)
Scope and Objectives
There were no Internet Drafts associated with this BOF. The intent was to review the Charter, agree on WG formation and agree on the work associated with this initiative. It was not the intent to debate solutions to the requirements tabled.
Concepts and Requirements
A brief overview of key concepts related to Packet Transport Rings (PTR) was presented together with the requirements for closer Layer2-Layer3 Interaction. The concepts presented were fundamental building blocks of the PTR MAC layer and were not expected to change as standardization efforts progressed within the IEEE's Resilient Packet Rings Study Group (RPRSG). The following is a summary of Concepts and related Layer 3 Requirements:
1. Dual counter-rotating rings and spatial reuse / destination stripping with bandwidth consumed only on the traversed ring spans. Requirements: IGP knowledge of adjacencies (direct downstream and direct upstream neighbors); Appropriate LSA/LSP flooding mechanisms.
2. Uniform bandwidth on ring spans with hop-count metrics, insufficient for regional or national topologies with uneven node clusters and price sensitive spans. Requirements: Extensions to cost metrics to allow for flexible administrative weights.
3. Protection Switching Mechanisms within PTR wherein nodes adjacent to a fault wraps. Requirements: Immediate notification to IGP of lost neighbor for fast recalculation of paths and adjacencies.
4. PTR can support Passthrough mode wherein a node is operational and will forward packets but will not participate in Layer 3 packet processing. Requirements: Immediate notification to IGP of lost neighbor for fast recalculation of paths and adjacencies as well as adjustment of cost metrics to reflect changes.
5. Hierarchical Rings wherein Access rings attach to Aggregation and Intra-POP rings into regional and WAN rings. Requirements: Support for Traffic Engineering extensions.
6. Other Requirements: QoS and traffic priority mapping; MIB Definitions.
IEEE Related Activities
M. Takefman, chair of the IEEE RPRSG, presented a status of the work within the Study Group. The Study Group is currently working on a PAR (Project Authorization Approval) and a 5 Criteria Draft. The 5 Criteria Draft is based on: Broad Market Potential; Compatibility; Distinct Identity; Technical Feasibility; Economic Feasibility.
A brief overview of the objectives, processes and voting procedures was presented.
The next Interim meeting is scheduled for August 28-29 where the PAR and 5 Criteria Draft will be finalized. The plan is to present this to the Executive Committee at the next plenary.
The associated RPRSG webpage is as follows: http://www.ieee802.org/rprsg
Charter Review and Discussions
The following was the proposed Charter:
....The IPoPTR WG will deliver IPoPTR Specifications which will address interactions between Packet Transport Rings and the Routing Protocols. This will include enhancements and extensions to the IGPs, extensions to MPLS-TE, extension to QoS features as well as MIB definitions.
This WG will also provide an appropriate liaison to IEEE's RPRSG.
And the proposed Milestones were:
Jul / 00 Achieve consensus on IPoPTR WG Formation
Nov / 00 Achieve consensus on basics of IP interworking within PTRs
Mar / 01 Submit IPoPTR specifications to IESG for consideration as a Proposed Standard
Jul / 01 Re-evaluate status or re-charter
Comments and Concerns as follows:
- Concerns were voiced re: close interactions between the layers, abstractions between routing and MAC layers and a clean demarc. Comments were that there are benefits to be realized in areas such as convergence.
- Acknowledged that work had to be proposed to the Routing Area
- Questions were raised re: any Intellectual Property Rights that apply to this as well as RPR. The reply was that IPR rules apply similarly within the IEEE and IETF (as per Section 10, RFC2026). No Internet Drafts are being discussed at this BOF to warrant this concern. Requirements and request to form a WG was the only agenda at this meeting.
- Concerns re: TE implications were raised. Concerns were similar to the clear abstraction and demarc concerns raised earlier. This one specifically to TE functions that can be applied to either Layer 2 or Layer 3. Concerns noted.
- Concerns re: Multicast implications. Concerns noted.
- Concerns re: Work still underway at IEEE and the aggressive Milestones being proposed in this BOF. Comment was that concepts being addressed were generic enough and will hardly change as IEEE proceeds with their work. The milestones proposed were considered unrealistic. BOF chair re-iterated that these are simply proposals that are up for discussion and can be adjusted.
It was proposed that the IPoPTR WG first produce a Requirements and Framework document for review at the next IETF meeting. A new Charter will be drafted to reflect this.
After a review of the Requirements and Framework documents, a re-chartering of the WG will be performed.
Proposed Revised Charter
Recent enhancements to traditional bi-directional ring topologies provide substantial benefits in efficiency and flexibility. The objective is to leverage these and increase IP efficiencies across these rings. This includes close interaction of Layer 2 & 3 functions and features (i.e. alarm notification, fast restoration / convergence, traffic engineering).
The IPoPTR WG will first deliver a Requirements and Framework document for review before proceeding with specifications and extensions to the different protocols. After a review of the Requirements and Framework document, a re-chartering process will set the direction for the Workgroup's next work phase.
Upon re-chartering, IPoPTR WG plans to deliver IPoPTR Specifications which will address interactions between Packet Transport Rings and the Routing Protocols. This will include enhancements and extensions to the IGPs, extensions to MPLS-TE, extension to QoS features as well as MIB definitions.
The IPoPTR WG will continue a close liaison with IEEE's RPRSG.
End of Meeting Report