2.7.1 Internet Traffic Engineering (tewg)

NOTE: This charter is a snapshot of the 58th IETF Meeting in Minneapolis, Minnesota USA. It may now be out-of-date.

Last Modified: 2003-09-30

Ed Kern <ejk@tech.org>
Jim Boyle <jboyle@pdnets.com>
Sub-IP Area Director(s):
Bert Wijnen <bwijnen@lucent.com>
Alex Zinin <zinin@psg.com>
Sub-IP Area Advisor:
Bert Wijnen <bwijnen@lucent.com>
Mailing Lists:
General Discussion: te-wg@ops.ietf.org
To Subscribe: te-wg-request@ops.ietf.org
In Body: subscribe
Archive: http://ops.ietf.org/lists/te-wg
Description of Working Group:
Internet Traffic Engineering is defined as that aspect of Internet network engineering concerned with the performance optimization of traffic handling in operational networks, with the main focus of the optimization being minimizing over-utilization of capacity when other capacity is available in the network. Traffic Engineering entails that aspect of network engineering which is concerned with the design, provisioning, and tuning of operational internet networks. It applies business goals, technology and scientific principles to the measurement, modeling, characterization, and control of internet traffic, and the application of such knowledge and techniques to achieve specific service and performance objectives, including the reliable and expeditious movement of traffic through the network, the efficient utilization of network resources, and the planning of network capacity.

The Internet Traffic Engineering Working Group defines, develops, specifies, and recommends principles, techniques, and mechanisms for traffic engineering in the internet. The working group also serves as a general forum for discussing improvements to IETF protocols to advance the traffic engineering function.

The primary focus of the tewg is the measurement and control aspects of intra-domain internet traffic engineering. This includes provisioning, measurement and control of intra-domain routing, and measurement and control aspects of intra-domain network resource allocation. Techniques already in use or in advanced development for traffic engineering include ATM and Frame Relay overlay models, MPLS based approaches, constraint-based routing, and traffic engineering methodologies in Diffserv environments. The tewg describes and characterizes these and other techniques, documents how they fit together, and identifies scenarios in which they are useful.

The working group may also consider the problems of traffic engineering across autonomous systems boundaries.

The tewg interacts with the common control and measurement plane working group to abstract and define those parameters, measurements, and controls that traffic engineering needs in order to engineer the network.

The tewg also interacts with other groups whose scopes intersect, e.g. mpls, is-is, ospf, diffserv, ippm, rap, rtfm, policy, rmonmib, disman, etc.

The work items to be undertaken by TE WG encompass the following categories:

- BCP documents on ISP uses, requirements, desires (TEBCPs)

- Operational TE MIB (TEMIB)

- Document additional measurements needed for TE (TEM)

- TE interoperability & implementation informational notes (TEIMP)

- Traffic Engineering Applicability Statement (TEAPP)

For the time being, it also is covering the area of verification that diffserv is achievable in traffic engineered SP networks. This will entail verification and review of the Diffserv requirements in the the WG Framework document and initial specification of how these requirements can be met through use and potentially expansion of existing protocols.

Goals and Milestones:
Done  Solicit TEBCP drafts concerning requirements, approaches, lessons learned from use (or non use) of TE techniques in operational provider environments.
Done  Review and comment on operational TEMIB
Done  TEBCPs submitted for WG comment
Done  Comments to TEBCP authors for clarifications
Done  First draft of TEAPP
Done  First draft of TEM
Done  TE Framework Draft to AD/IESG for review.
Done  Drafts available for E-LSP and L-LSP Diffserv TE
Done  Another update of operational TEMIB draft
Done  All comments back on TE Diffserv requirements
Done  Submit revised TEBCPs and REAPP to AD/IESG for review
Oct 01  Progress operational TE MIB to AD review
Oct 01  Submit TEM draft for AD review
Nov 01  Any necessary protocol extensions for Diffserv TE sent to protocol relevant WGs for review.
Dec 01  Recharter
Jan 02  Progress Diffserv TE E-LSP and L-LSP Diffserv TE drafts together to AD/IESG for review
  • - draft-ietf-tewg-mib-07.txt
  • - draft-srisuresh-ospf-te-05.txt
  • - draft-ietf-tewg-measure-06.txt
  • - draft-ietf-tewg-diff-te-proto-05.txt
  • - draft-ietf-tewg-te-metric-igp-02.txt
  • - draft-ietf-tewg-diff-te-russian-04.txt
  • - draft-ietf-tewg-diff-te-mar-02.txt
  • - draft-ietf-tewg-interas-mpls-te-req-01.txt
  • - draft-ietf-tewg-diff-te-mam-01.txt
  • Request For Comments:
    RFC3272 I Overview and Principles of Internet Traffic Engineering
    RFC3346 I Applicability Statement for Traffic Engineering with MPLS
    RFC3386 I Network Hierarchy and Multilayer Survivability
    RFC3564 I Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering

    Current Meeting Report

    Internet Traffic Engineering WG (tewg)  
    Thursday,  November 13 at 0900-1130
    CHAIRS:	Ed Kern <ejk@tech.org>
    	Jim Boyle <jboyle@pdnets.com>
    0900-0910       Agenda                          Chairs
                    Document Status Update
    0910-0940       Diffserv TE
                    Proto, RDM, MAM, MAR            Francois
                    Model Comparison                Waisum
    0940-1000       TE Measurement                  Waisum
    1000-1030       Inter-area / Inter-AS           Raymond / Jim
    1030-1045       Preemption Analysis             Jaudelice
    1045-1055       Mib Update                      Kireeti
    1055-1130       WG status and future            Chairs
    0910-0940       Diffserv TE
                    Proto, RDM, MAM, MAR            Francois
       In Vienna, an issue was raised that there may be a problem with 
    relationship between shared mesh restoration and DS-TE BC models. 
    Investigation conclusion that these can work together provided Shared Mesh 
    Restoration operates independently within each CT. This was explained on 
    list. Drafts have been updated before WG Last Call to reflect this.
       A second issue was raised in draft-sivabalan (on DSTE over TE Link 
    Bundles) which could be generalised into the question of how to 
    generically specify DS-TE operations over any MPLS TE extensions (eg TE 
    link Bundle, FA-LSP,...). -proto draft has been updated before WG Last Call 
    to reflect this (in particular new section 7 on this topic).
                    Model Comparison                Waisum
       Wai Sum: All comments from the previous meeting and on the list have now 
    been incorporated.  As agreed in the previous two meetings, this draft is to 
    progress as an independent submission to the RFC Editor, with TEWG 
       Francois: I think this is a useful document and support its going 
       Wai Sum: I would like to thank both Francois and his colleague Anna 
    Charny at Cisco whom I worked with extensively offline.  I think the 
    document now reflects a fair comparison.
    0940-1000       TE Measurement                  Waisum
       Revision based on AD feedback completed. Main body of text 
    shortened, with ancilliary information moved to annexes.  Clearly 
    identified requirements:
       + for network dimensioning, mechanisms to collect node-pair based 
    traffic data
       + for service assurance, higher order stastics required
       + present representative traffic detail at reasonable sample volumes
       + be able to manage large volumes of data
       Jim: Question as to what effect this draft can have, feel that we have 
    mixed our mark.
       Raymond: These requirements are quite critically needed by SPs 
    entering this space.
       Jerry: The first question is whether we are dropping the TEM 
    milestone.  If we are not, the next question is why specifically 
    <draft-ietf-tewg-measure-06.txt> doesn't meet the milestone.  There are 
    specific requirements in the draft that will lead to critically needed 
    protocol extensions and/or MIB extensions.  If these requirements are not 
    valid or already fulfilled somewhere, Jim and/or Bert need to say why, 
    where, and how.  There was an extensive discussion of the list back in 
    April-May.  Many people representing several service providers have read the 
    draft and commented extensively on the list back in the April-May 
    timeframe, this discussion is available in the list archive.  The only 
    negative comments in the entire discussion were Bert's.  The TEM 
    milestone should be met, the draft meets the need, and should 
       Jim: We will have to agree to disagree on this one.  For feedback, see my 
    comments to revision 5 which were not addressed.  As chair, I have not seen 
    much support on the lists.  Who has read recent version (show of hands 
    indicates not many), any version (not many). Think its best to not 
    progress this and just fail to deliver on this WG objective.
    1000-1030       Inter-area / Inter-AS           Raymond / Jim
       Raymond - Inter-as now includes AS-object.  Stressed that 
    requirements are only for IP layer networks now.  Once -02 posted, should be 
    ready for WG last call.
       Adrian - CCAMP should understand that these requirements are coming and 
    have a chance to review.  Adrian to send notice to ccamp.
       Jim - Will remove inter-as from interarea draft, should this be a WG 
       JP - No, it currently is pretty light and has no obvious input or 
    support by providers.
       Kireeti - CCAMP is working on solution, and likely there will be 1 
    solution to address both of these, so it would be good to get both 
    requirements delivered together.
       Adrian - is there functional similarities between inter-as and 
       Jim - I believe so.
       Raymond - Application scenarios and some functional requirements are 
    1030-1045       Preemption Analysis             Jaudelice
       Feedback from floor was that it would be interesting to see this under 
    variety of network loading.
    1045-1055       Mib Update                      Kireeti
       Looks ready to go now, and will stay within IESG.
       Jim: SO what about Diff Serv TE?
       Kireeti: In a sense, this mib can be used, however you will not be able to 
    read back information like mapping of TE-Class to P and CT.
       Jim: One thought is that Diff Serv TE MIB work could be done as part of 
    MPLS MIB work in mpls WG.  
       Bert:  Has to revisit where these mibs are before they take that on.
    1055-1130       WG status and future            Chairs
       See presentation, but sense from the room was that it was right time to 
    close the WG (after interarea and inter-as reqs done). Should anything be 
    needed for TE in the future, a BOF could be used to gauge the need and 


    DS-TE protocol Extensions
    Bandwidth Constraints Models for Diffserv-aware MPLS TE: Performance Evaluation
    Requirements for Internet Traffic Engineering Measurement
    Inter-AS MPLS TE Requirements
    Inter Area TE Requirements
    Preemption Analysis