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TRILL Header Extension Improvements

TRILL Header Extension Improvements. Donald Eastlake 3 rd Huawei Technologies d3e3e3@gmail.com. TRILL Header Extensions. Updates from Beijing Meeting Replace single (4-byte) first word of “ bit encoded options ” with two words: First word now has a Flow ID and fewer flag bits

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TRILL Header Extension Improvements

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  1. TRILL Header Extension Improvements Donald Eastlake 3rd Huawei Technologies d3e3e3@gmail.com

  2. TRILL Header Extensions • Updates from Beijing Meeting • Replace single (4-byte) first word of “bit encoded options” with two words: • First word now has a Flow ID and fewer flag bits • Optional second word has more flag bits • Tweak TLV encoding to provide more Types • Update ECN (Explicit Congestion Notification) option to correspond with RFC 6040 • Update from mailing list • “Bit encoded options” -> “Extended Header Flags”

  3. TRILL Data Frame Format Link Specific Header TRILL Header Header Extensions Inner Ethernet DA Inner Ethernet SA Inner Frame VLAN Tag Payload Link Specific Trailer

  4. Improvements • Multiple extension fields at a fixed offset from the start of the TRILL Header have been discussed. • Additional priority / QoS information • Fine grained data label • More extended flags • Saved VLAN tag • Other…

  5. Improvements • One solution is to provide for additional optional TRILL Header Extension words whose presence is indicated by the value of Op-Length.

  6. Improvements • The closer a field is to being a fixed size at a fixed offset, the easier it is to use it in the fast path. • These factors are more important for something referenced at each hop that something set at ingress and used only at egress. • TLV options, while very flexible, are hard for fast path hardware to use.

  7. TRILL Header, Base Protocol Draft Flags OpLen Hops Nicknames | | Reserved . TLV Options Critical Summary bits indicate if it is safe for a transit or egress RBridge that does not implement any extensions to process the frame.

  8. TRILL Header, After Beijing Flags OpLen Hops Nicknames | | . Flow ID More Flags TLV Options Critical Summary bits indicate if it is safe for a transit or egress RBridge that does not implement any extensions to process the frame. Current: draft-ietf-trill-rbridge-options-04.txt

  9. TRILL Header, Improved Flags OpLen Hops Nicknames | | . Flow ID Fixed Extension Fields Fixed Extension Fields • • • TLV Options Critical Summary bits indicate if it is safe for a transit or egress RBridge that does not implement any extensions to process the frame.

  10. Improved Header Extensions Example Extended Flags | Flow ID . (1) More Extended Flags | Other (2) Priority | Data Label . Saved VLAN Tag TLV Options • First word present if OpLength is non-zero. • Presence of additional words independently indicated by Extended Flags info in the first word.

  11. Proposed WG Actions • Rename “options” draft as “extensions” draft. • Update draft along the lines indicated in this presentation • Current draft:draft-ietf-trill-rbridge-options-04.txt • Issue Working Group Last Call on revised draft

  12. END Donald Eastlake 3rd Huawei Technologies d3e3e3@gmail.com

  13. Back Up Slides Donald Eastlake 3rd Huawei Technologies d3e3e3@gmail.com

  14. Nomenclature Change • Approved on mailing list, from TRILL Header TRILL Header Bit Encoded Options + Flow ID Extended Header Flags / Flow ID TLV Options TLV Options • To

  15. Current Header ExtensionsFirst 32 Bits • Present if OpLng in TRILL Header > 0 Flow ID, Non-zero if valid NC. I-t-E Bit C. I-t-E Bits C. H-b-H Bits Non-Critical Ingress-to-Egress TLV Option Present NC. H-b-H Bits Critical Ingress-to-Egress TLV Option Present Non-Critical Hop-by-Hop TLV Option Present More Extended Flags Critical Ingress-to-Egress Summary Bit Critical Hop-by-Hop Summary Bit

  16. Current Header ExtensionsSecond 32 Bits • If “More Extended Flags” bit is a one, there are 4 bytes of additional extended header flags as follows: Critical Hop-by-Hop Non-Critical Hop-by-Hop Critical Ingress-to-Egress Non-Critical Ingress-to-Egress

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