me too. 

If we want to align the encoding, we should probably better align the protocol 
name directly...

s.


> On Apr 3, 2018, at 9:34 AM, Peter Psenak <ppse...@cisco.com> wrote:
> 
> On 02/04/18 14:19 , Acee Lindem (acee) wrote:
>> Speaking as WG member:
>> 
>> I couldn’t agree more with Ketan. No changes are required to these
>> documents.
> 
> as a coauthor of the OSPF/OSPFv3 SR drafts, I fully agree.
> 
> thanks,
> Peter
> 
>> 
>> Thanks,
>> 
>> Acee
>> 
>> *From: *Lsr <lsr-boun...@ietf.org> on behalf of "Ketan Talaulikar
>> (ketant)" <ket...@cisco.com>
>> *Date: *Monday, April 2, 2018 at 7:36 AM
>> *To: *Aijun Wang <wangai...@tsinghua.org.cn>
>> *Cc: *"lsr@ietf.org" <lsr@ietf.org>
>> *Subject: *Re: [Lsr] Inconsistence regarding the definition of "Adj-SID
>> Sub-TLV" between OSPF and ISIS extension for Segment Routing
>> 
>> Hi Aijun,
>> 
>> I understand what you are referring to now, but these are not
>> inconsistencies. ISIS, OSPF and BGP-LS are 3 different protocols. Their
>> encodings may not all be the same. ISIS uses 1 byte for type/length and
>> has LSP space constraints which you would notice in the protocol
>> encodings. OSPF doesn’t have the same challenge and you would notice how
>> its TLVs tend to be aligned. BGP-LS is somewhat similar to OSPF from
>> these size constraints perspective.
>> 
>> I do not see the implementation challenges in encoding from the two IGPs
>> into BGP-LS. It does not make sense to change any of the protocol
>> encodings that you ask for currently since implementations have been
>> shipping with them for many years.
>> 
>> IMHO it is not necessary to put such constraints for what you call
>> “consistency” on these 3 protocol encodings in the future. However, we
>> do try to be consistent in semantics as much as possible.
>> 
>> Thanks,
>> 
>> Ketan
>> 
>> *From:*Aijun Wang <wangai...@tsinghua.org.cn>
>> *Sent:* 02 April 2018 16:52
>> *To:* Ketan Talaulikar (ketant) <ket...@cisco.com>
>> *Cc:* lsr@ietf.org
>> *Subject:* Re: [Lsr] Inconsistence regarding the definition of "Adj-SID
>> Sub-TLV" between OSPF and ISIS extension for Segment Routing
>> 
>> Hi, Ketan:
>> 
>> There is one two-bytes “Reserved” field in “Adjacency Segment
>> Identifier” TLV for OSPF extension, but this field doesn’t exist in the
>> corresponding TLV for ISIS extension. Every other fields are same.
>> 
>> Corresponding definition in BGP-LS is similar with OSPF(not similar with
>> ISIS as I mentioned in previous mail). Then when the router
>> reports/redistributes the ISIS LSDB information to BGP protocol, the
>> router must add two bytes to the “length” field and add/stuff the
>> “reserved” field; but for OSPF LSDB, the router need only copy the
>> corresponding fields according.
>> 
>> We have found the error arises from this inconsistency from the real
>> router and think it is better to align this definition in different IGP
>> protocol.
>> 
>> Update to ISIS related extensions draft may be easier.
>> 
>> Aijun Wang
>> 
>> China Telecom
>> 
>> 
>> 在 2018年4月2日,18:26,Ketan Talaulikar (ketant)
>> <ket...@cisco.com<mailto:ket...@cisco.com>> 写道:
>> 
>>    Hi Aijun,
>> 
>>    Can you clarify what you mean by “inconsistencies”?
>> 
>>    Also, you are referring the old version of OSPFv3 SR draft before it
>>    was aligned with the OSPFv2 SR draft. Please check
>>    
>> https://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-routing-extensions-11#section-6.1
>> 
>>    OSPF and ISIS are different protocols and there are some differences
>>    between them. I would not call them inconsistencies. BGP-LS spec
>>    refers to the individual IGP drafts for interpretation of flags. So
>>    please specifically point out what inconsistency you are referring to.
>> 
>>    Thanks,
>> 
>>    Ketan
>> 
>>    *From:*Lsr <lsr-boun...@ietf.org<mailto:lsr-boun...@ietf.org>> *On
>>    Behalf Of *Aijun Wang
>>    *Sent:* 02 April 2018 14:23
>>    *To:* lsr@ietf.org<mailto:lsr@ietf.org>
>>    *Subject:* [Lsr] Inconsistence regarding the definition of "Adj-SID
>>    Sub-TLV" between OSPF and ISIS extension for Segment Routing
>> 
>>    Hi, All:
>> 
>>    We found there were some inconsistences for the definition of
>>    “Adjacency Segment Identifier” between OSPF and ISIS extension for
>>    segment routing, please see the link below for comparison.
>> 
>>    
>> https://tools.ietf.org/html/draft-ietf-isis-segment-routing-extensions-15#section-2.2.1
>> 
>>    
>> https://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment-routing-extensions-10#section-7.1
>> 
>>    Here we want to know is there any reason for this inconsistence? We
>>    think this inconsistence can easily cause error for BGP-LS
>>    implementation for segment routing extension, as that defined in
>>    
>> https://tools.ietf.org/html/draft-ietf-idr-bgp-ls-segment-routing-ext-04#section-2.2.1,
>>    which is similar with ISIS extension for SR, but different from OSPF
>>    extension for SR.
>> 
>>    Do we need to make them consistent? It seems change the definition
>>    in OSPF extension may be less influence for the existing related drafts.
>> 
>>    Best Regards.
>> 
>>    Aijun Wang
>> 
>>    Network R&D and Operation Support Department
>> 
>>    China Telecom Corporation Limited Beijing Research
>>    Institute,Beijing, China.
>> 
>>    _______________________________________________
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>> 
>> 
>> 
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