Re: [Srcomp] CSID and VSID analysis in section 3

[Ron Bonica <[e-mail]>]

Cheng Li,

Why can't the VSID satisfy the requirement in 3.2.2 using a binding SID?

                                                       Ron




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From: Srcomp <[e-mail]> On Behalf Of Chengli (Cheng Li)
Sent: Monday, April 12, 2021 9:57 PM
To: 'srcomp' <[e-mail]>
Subject: [Srcomp] CSID and VSID analysis in section 3

[External Email. Be cautious of content]


Hi all,



Here is my output of CSID and VSID in section 3.



Thanks,

Cheng


3.1<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.1__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-RtjgJIT$>.  SRv6 Based





   A solution to compress SRv6 SID Lists SHOULD be based on the SRv6

   architecture, control plane and data plane.  The compression solution

   MAY be based on a different data plane and control plane, provided

   that it derives sufficient benefit.



   This section records the use of SRv6 standards for compression.



                 +-----------+------+-----+------+-------+

                 |           | CSID | CRH | VSID | UIDSR |

                 +-----------+------+-----+------+-------+

                 | U.RFC8402<https://urldefense.com/v3/__https:/tools.ietf.org/html/rfc8402__;!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-cguwU_H$> |  Y   |     |   Y  |       |

                 | U.RFC8754<https://urldefense.com/v3/__https:/tools.ietf.org/html/rfc8754__;!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-SneBCkU$> |  Y   |     |   Y  |       |

                 | U.PGM     |  Y   |     |   Y  |       |

                 | U.IGP     |  Y   |     |   Y  |       |

                 | U.BGP     |  Y   |     |   Y  |       |

                 | U.POL     |  Y   |     |   Y  |       |

                 | U.BLS     |  Y   |     |   Y  |       |

                 | U.SVC     |  Y   |     |   Y  |       |

                 | U.ALG     |  Y   |     |   Y  |       |

                 | U.OAM     |  Y   |     |   Y  |       |

                 +-----------+------+-----+------+-------+



                            Table 6: SRv6 Based



   Conclusion:



3.2<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.2__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-dg2KU6r$>.  Functional Requirements





3.2.1<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.2.1__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-V0Q7itO$>.  SRv6 Functionality





   A solution to compress an SRv6 SID list MUST support the

   functionality of SRv6.  This requirement ensures no SRv6

   functionality is lost.  It is particularly important to understand









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Internet-Draft             SRCOMP Requirements             February 2021





   how a proposal, as evaluated in section "SRv6 Based", provides this

   functionality.



   Functional requirements and the drafts defining how a proposal

   provides the functionality are documented in the table below.



         +------------------------------------------------------+

         | Draft reference Abbreviations                        |

         +------------------------------------------------------+

         | IDNETPGM: [I-D.ietf-spring-srv6-network-programming<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-spring-srv6-network-programming__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-bfL53wN$>] |

         | IDSRPOL: [I-D.ietf-spring-segment-routing-policy<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-spring-segment-routing-policy__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-V8C2SQO$>]    |

         | IDEXT: [I-D.ietf-lsr-isis-srv6-extensions<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-lsr-isis-srv6-extensions__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-R8P6FgE$>]           |

         | IDBGPSVC: [I-D.ietf-bess-srv6-services<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-bess-srv6-services__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-UBaw2pG$>]              |

         | IDBGPLS: [I-D.ietf-idr-bgpls-srv6-ext<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-idr-bgpls-srv6-ext__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-bmncgYX$>]               |

         | IDSVCP: [I-D.ietf-spring-sr-service-programming<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-spring-sr-service-programming__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-T4rZSYM$>]     |

         | IDOAM: [I-D.ietf-6man-spring-srv6-oam<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-6man-spring-srv6-oam__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-YMtj90o$>]               |

         | IDFLEXALG: [I-D.ietf-lsr-flex-algo<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-lsr-flex-algo__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-awS99LG$>]                  |

         | IDTILFA: [I-D.ietf-rtgwg-segment-routing-ti-lfa<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*ref-I-D.ietf-rtgwg-segment-routing-ti-lfa__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-fqMCfs0$>]     |

         +------------------------------------------------------+



                  +---------+------+-----+------+-------+

                  |         | CSID | CRH | VSID | UIDSR |

                  +---------+------+-----+------+-------+

                  | F.SID   |  Y   |     |  Y   |       |

                  | F.Scope |  Y   |     |  Y   |       |

                  | F.PFX   |  Y   |     |  Y   |       |

                  | F.ADJ   |  Y   |     |  Y   |       |

                  | F.BIND  |  Y   |     |  Y   |       |

                  | F.PEER  |  Y   |     |  Y   |       |

                  | F.SVC   |  Y   |     |  Y   |       |

                  | F.ALG   |  Y   |     |  Y   |       |

                  | F.TILFA |  Y   |     |  Y   |       |

                  | F.SEC   |  Y   |     |  Y   |       |

                  | F.IGP   |  Y   |     |  Y   |       |

                  | F.BGP   |  Y   |     |  Y   |       |

                  | F.POL   |  Y   |     |  Y   |       |

                  | F.BLS   |  Y   |     |  Y   |       |

                  | F.SFC   |  Y   |     |  Y   |       |

                  | F.PING  |  Y   |     |  Y   |       |

                  +---------+------+-----+------+-------+



                        Table 7: SRv6 Functionality



   Conclusion:















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Internet-Draft             SRCOMP Requirements             February 2021





3.2.2<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.2.2__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-cWsEiQC$>.  Heterogeneous SID Lists





   The compression proposal SHOULD support a combination of compressed

   and non-compressed segments in a single path.  As an example, a

   solution may satisfy this requirement without being SRv6 based by

   using a binding SID to impose an additional SRv6 header (IPv6 header

   plus optional SRH) with non-compressed SID.



          +-------------------------+------+-----+------+-------+

          |                         | CSID | CRH | VSID | UIDSR |

          +-------------------------+------+-----+------+-------+

          | Heterogeneous SID Lists |   Y  |     |  N   |       |

          +-------------------------+------+-----+------+-------+



   Conclusion:



3.2.3<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.2.3__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-ZZcIK8H$>.  SID List Length





   The compression proposal MUST be able to represent SR paths that

   contain up to 16 segments.



                +-------------+------+-----+------+-------+

                |             | CSID | CRH | VSID | UIDSR |

                +-------------+------+-----+------+-------+

                | 16 Segments |  Y   |     |  Y   |       |

                +-------------+------+-----+------+-------+



   Conclusion:



3.2.4<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.2.4__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-cyqMq1c$>.  SID Summarization





   The solution MUST be compatible with segment summarization.



   In inter sub-domain deployments with summarization:



   o  Any node can reach any other node in another sub-domain via a

      prefix segment.

   o  Prefixes are summarized for advertisement between domains.



   Without summarization, border router SIDs must be leaked:



   o  An additional global prefix segment is required for each domain

      border to be traversed.

















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Internet-Draft             SRCOMP Requirements             February 2021





             +-------------------+------+-----+------+-------+

             |                   | CSID | CRH | VSID | UIDSR |

             +-------------------+------+-----+------+-------+

             | SID Summarization |  Y   |     |  Y   |       |

             +-------------------+------+-----+------+-------+



   Conclusion:



3.3<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.3__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-cp6bjRG$>.  Operational Requirements





3.3.1<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.3.1__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-fSlFQD9$>.  Lossless Compression





   A path traversed using a compressed SID list MUST always be the same

   as the path traversed using the uncompressed SID list if no

   compression was applied.



           +----------------------+------+-----+------+-------+

           |                      | CSID | CRH | VSID | UIDSR |

           +----------------------+------+-----+------+-------+

           | Lossless Compression |  Y   |     |  Y   |       |

           +----------------------+------+-----+------+-------+



   Conclusion:



3.4<https://urldefense.com/v3/__https:/tools.ietf.org/html/draft-srcompdt-spring-compression-analysis-00*section-3.4__;Iw!!NEt6yMaO-gk!UZnqhTYxUuL0rIfenxzxw5p9KXtx2sd3K8FK_oQQxfN_p1SNpDT8JMkE-Wy_jZQ1$>.  Scalability Requirements





   The compression proposal MUST be capable of representing 65000

   adjacency segments per node.



   The compression proposal MUST be capable of representing 1 million

   prefix segments per SID numbering space.



   The compression proposal MUST be capable of representing 1 million

   services per node.



       +-------------------------------+------+-----+------+-------+

       |                               | CSID | CRH | VSID | UIDSR |

       +-------------------------------+------+-----+------+-------+

       | Adjacency Segment Scale 65000 |      |     |      |       |

       | Prefix Segment Scale 1000000  |  Y   |     |  Y   |       |

       | Service Scale 1000000         |      |     |      |       |

       +-------------------------------+------+-----+------+-------+



                        Table 8: Scale Requirements



   Conclusion: