Independent Submission U. Keten Internet Draft Turk Telekom A.S. Intended status: Proposed Standard September 15, 2016 Expires: February 2017 MPLS EXP/TC BIT EXPANSION draft-keten-mpls-expbit-02.txt Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html This Internet-Draft will expire on FEB 14, 2016. Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Keten Expires February 15, 2016 [Page 1] Internet-Draft MPLS EXP/TC BIT EXPANSION September 2016 Abstract This document specifies the new label/header architecture for a new Multiprotocol Label Switching and proposes a new Label Standard. With this new architecture the aim is to provide more QoS options. Table of Contents 1. Introduction ................................................ 3 2. Conventions used in this document............................ 3 3. Overview and Current Encoding of the Label Stack............. 4 4. New Proposed Encoding of the Label Stack..................... 4 5. More QoS parameters ......................................... 5 6. Backwards Compatability...................................... 5 7. Formal Syntax ............................................... 5 8. Security Considerations...................................... 5 9. IANA Considerations ......................................... 5 10. Conclusions ................................................ 5 11. References ................................................. 6 11.1. Normative References................................... 6 11.2. Informative References................................. 6 12. Acknowledgments ............................................ 6 Keten Expires February 15, 2016 [Page 2] Internet-Draft MPLS EXP/TC BIT EXPANSION September 2016 1. Introduction This internet draft outlines a proposed change for the MPLS architecture as defined in RFC 3031 and the MPLS Label Stack Encoding RFC 3032 to suit the need of differentiated services and their requirements for more differentiated QoS. Current services require more specific QoS parameters then the 8 possibilities provided by the 3 bit in the EXP/COS/TC field. 3 bits is not enough to differentiate in our current service oriented environment. With this Proposed Standard a possibility of 32 QoS settings can be achieved. 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. In this document, these words will appear with that interpretation only when in ALL CAPS. Lower case uses of these words are not to be interpreted as carrying significance described in RFC 2119. In this document, the characters ">>" preceding an indented line(s) indicates a statement using the key words listed above. This convention aids reviewers in quickly identifying or finding the portions of this RFC covered by these keywords. Keten Expires February 15, 2016 [Page 3] Internet-Draft MPLS EXP/TC BIT EXPANSION September 2016 3. Overview and Current Encoding of the Label Stack The current label stack as described in RFC 3032 is represented as a sequence of "label stack entries". Each label stack entry is represented by 4 octets. This is shown in Figure 1: Octets 0 1 2 3 4 Bits 1 2 3 4 5 6 7 8 Label -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+-+-+-+-+- Stack | Label | EXP |S| TTL | Entry -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+-+-+-+-+- Figure 1 Label: Label Value, 20 bit EXP/TC/COS: 3 bits defined as TC, RFC 5462 S: Bottom of Stack, 1 bit TTL: Time to Live, 8 bits 4. New Proposed Encoding of the Label Stack The New label stack described is represented as the same sequence of "label stack entries" as in RFC 3032. However the assigned 8 bits to TTL have been deducted by 2, to a total of 6 bits and added to a new complimentary QoS X stack which will be a 2 bits entry. This is shown in Figure 2. Octets 0 1 2 3 4 Bits 1 2 3 4 5 6 7 8 Label -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+-+-+-+-+- Stack | Label | EXP |S| X | TTL | Entry -+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+-+-+-+-+-+-+-+-+-+- Figure 2 Label: Label Value, 20 bit EXP/TC/COS: 5 bits defined in New Proposed Format S: Bottom of Stack, 1 bit X: Complimentary QoS bits TTL: Time to Live, 6 bits Keten Expires February 15, 2016 [Page 4] Internet-Draft MPLS EXP/TC BIT EXPANSION September 2016 5. More QoS parameters With the addition of 2 more complimentary bits as the X stack, more QoS parameters can be set to suit the needs of current IP Internet services. MPLS networks will not need such large TTL's, taking the 2 most-significant-bits from the TTL and giving them a different purpose could have more meaning. 6. Backwards Compatability Assumed is that these most-significant-bits bits will "never" be decremented. For consideration is that certain OAM mechanisms do rely on TTL decrementing to zero to trap frames. This is to specify that OAM protocols in this new architecture would never set these "extended" TC bits. Intended is to use these as extra "trash" tiers. Alternatively, these could be considered as "premium" trash tiers and hopping too much is grounds to have your extended TC "downgraded". In terms of implementation as a software upgrade in existing gear, this should be doable. NPU/FPGA/NFV-based solutions could add this functionality with a software upgrade. Semi-programmable ASICs could do this with some reconfiguration/programming. Only fully baked-in ASICs would have difficulty implementing this. 7. Formal Syntax The following syntax specification uses the augmented Backus-Naur Form (BNF) as described in RFC-2234 [RFC2234]. 8. Security Considerations There are no security considerations. 9. IANA Considerations This document has no actions for IANA. 10. Conclusions With this document a necessary and easy change is advised. More diverse QoS settings will enable a more service oriented network. Keten Expires February 15, 2016 [Page 5] Internet-Draft MPLS EXP/TC BIT EXPANSION September 2016 11. References 11.1. Normative References [1] Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001. [2] Rosen, E., Tappan, D. Fedorkow G., Y. Rekhter, D. Farinacci, T. Li, A. Conta "MPLS Label Stack Encoding", RFC 3032, January 2001 [3] Bradner, S.,"Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [4] L. Andersson, Acreo AB, R. Asati, Multiprotocol Label Switching (MPLS) Label Stack Entry:"EXP" Field Renamed to "Traffic Class" Field,RFC 5462, February 2009 11.2. Informative References No Informative References 12. Acknowledgments This document was prepared using 2-Word-v2.0.template.dot. Authors' Addresses Umut Keten Turk Telekom A.S. Ankara GM Phone: +90 553 349 9669 Email: umut.keten@turktelekom.com.tr Keten Expires February 15, 2016 [Page 6]