Hi Stéphane,

Le 02/09/2016 11:48, LITKOWSKI Stephane OBS/OINIS a écrit :
>
> Hi Olivier,
>
>  
>
> If we state that ERO is mandatory, it must always be present, so we need to 
> have it in the marker also. Not having it in the marker is possible but this 
> may require to introduce a different sanity check logic for this particular 
> PCRpt (so adding code complexity and bugs ..).
>
Agree. So, if the goal is to have a simple code without complexity and bug, 
only one marker and a simple 'if PLSP-ID == 0' instruction is largely 
sufficient. Here, the standard impose to test 5 more conditions before deciding 
is it is really an End Of Sync. Why complicate things when they can be simple 
;-). It just propose to simplify the process.

Regards

Olivier
>
> Again we having running codes now, so yes , it had been possible to use a 
> flag in the last LSP advertisement to tell that this is the last one, but now 
> EOS has been introduced and implemented and it would be hard to change this 
> without breaking current implementations or complexify them.
>
> Honestly having this empty ERO is not an issue and does not introduce any 
> issue.
>
>  
>
> Brgds,
>
>  
>
> Stephane
>
>  
>
>  
>
> *From:*Olivier Dugeon [mailto:[email protected]]
> *Sent:* Friday, September 02, 2016 11:16
> *To:* LITKOWSKI Stephane OBS/OINIS; Ina Minei
> *Cc:* [email protected]
> *Subject:* Re: [Pce] draft-ietf-pce-stateful-pce : clarifying the End Of 
> Synchronization marker
>
>  
>
> Hi all,
>
> I don't understand why you need to mention en empty ERO to mark en the end of 
> synchronisation. Comparing with what other protocols do to mark the end of 
> sync, I have a felling that we duplicate the marker. At least, a simple flag 
> i.e. 1 bit is largely sufficient to say that this is the last LSP. So, a 
> PCRpt message with PLSP-ID equal to the reserved value 0 is largely 
> sufficient. No need to add extra information, and if there are present, just 
> ignore them.
>
> If multiple marker are needed, I would suggest to used the NO_PATH object 
> define in RFC5440 instead of an empty ERO that has a variable interpretation. 
> The NO_PATH object has been define exactly for this meaning: there is no path.
>
> Regards
>
> Olivier
>
> Le 08/08/2016 11:06, [email protected] 
> <mailto:[email protected]> a écrit :
>
>     Hi Ina,
>
>      
>
>     Thanks for the feedback and proposal
>
>     I would like to propose those modifications :
>
>     “The end of synchronization marker is a PCRpt message with PLSP-ID equal 
> to the reserved value 0 (see Section 7.3). In this case, the LSP Object 
> SHOULD NOT include the SYMBOLIC-PATH-NAME TLV, SHOULD include the LSP- 
> IDENTIFIERS TLV with the special value of all zeroes. All the flags of the 
> LSP Object MUST be set to 0. The PCRpt message MUST include an empty ERO as 
> its intended path and SHOULD NOT include the optional RRO object for its 
> actual path or any other object. If the PCC has no state to synchronize, it 
> SHOULD only send the end of synchronization marker.”
>
>      
>
>      
>
>      
>
>     It would be good to add a sentence in case of bad encoding of the EOS 
> marker. This may be covered but it looks confusing to mix generic PCRpt with 
> EOS  :
>
>     “The PCE does not send positive acknowledgements for properly received
>
>        synchronization messages.  It MUST respond with a PCErr message with
>
>        error-type 20 (LSP State Synchronization Error) and error-value 1
>
>        (indicating an error in processing the PCRpt) (see Section 8.5) if it
>
>        encounters a problem with the LSP State Report it received from the
>
>        PCC and it MUST terminate the session.
>
>     “
>
>      
>
>     Some error examples :
>
>     1)      PCRpt S=0 D=0  PLSP-ID 0 LSP-Object (LSP-ID 0.0.0.0) ERO empty 
> RRO present
>
>     Need an error like : LSP State Synchronization Error, non authorized 
> object in EOS
>
>      
>
>     2)      PCRpt S=0 D=0 PLSP-ID 0 LSP-Object (LSP-ID 0.0.0.0) ERO empty BW=0
>
>     Need an error like : LSP State Synchronization Error, non authorized 
> object in EOS
>
>      
>
>     3)      PCRpt S=1 D=0 PLSP-ID 0 LSP-Object (LSP-ID 0.0.0.0) ERO empty
>
>     Need an error like : LSP State Synchronization Error, bad flags in EOS
>
>      
>
>     4)      PCRpt S=0 D=1 PLSP-ID 0 LSP-Object (LSP-ID 0.0.0.0) ERO empty
>
>     Need an error like : LSP State Synchronization Error, bad flags in EOS
>
>      
>
>     5)      PCRpt S=0 D=0 PLSP-ID 0 LSP-Object (LSP-ID 0.0.0.0) ERO non empty
>
>     Need an error like : LSP State Synchronization Error, bad ERO in EOS
>
>      
>
>     6)      PCRpt S=0 D=0 PLSP-ID 0 LSP-Object (LSP-ID 0.0.1.1) ERO  empty
>
>     Need an error like : LSP State Synchronization Error, bad LSP ID in EOS
>
>      
>
>     7)      PCRpt S=0 D=0 PLSP-ID 0 LSP-Object (LSP-ID 0.0.0.0)
>
>     Handled by Missing ERO in PCRpt which will apply to EOS as well
>
>      
>
>     A generic error would also work but less precise : LSP State 
> Synchronization Error, bad EOS encoding.
>
>      
>
>      
>
>     Best Regards,
>
>      
>
>     Stephane
>
>      
>
>      
>
>     *From:*Ina Minei [mailto:[email protected]]
>     *Sent:* Thursday, July 28, 2016 20:15
>     *To:* LITKOWSKI Stephane OBS/OINIS
>     *Cc:* Robert Varga; [email protected] <mailto:[email protected]>
>     *Subject:* Re: [Pce] draft-ietf-pce-stateful-pce : clarifying the End Of 
> Synchronization marker
>
>      
>
>     Stephane, 
>
>      
>
>     Thank you for the detailed feedback. How about the following text?
>
>      
>
>     The end of synchronization marker is a PCRpt message with the SYNC Flag 
> set to 0 for an LSP Object with PLSP-ID equal to the reserved value 0 (see 
> Section 7.3). In this case, the LSP Object SHOULD NOT include the 
> SYMBOLIC-PATH-NAME TLV and SHOULD include the LSP- IDENTIFIERS TLV with the 
> special value of all zeroes. The PCRpt message MUST include an empty ERO as 
> its intended path and SHOULD NOT include the optional RRO object for its 
> actual path. If the PCC has no state to synchronize, it SHOULD only send the 
> end of synchronization marker.
>
>      
>
>     On Mon, Jun 27, 2016 at 5:20 AM, <[email protected] 
> <mailto:[email protected]>> wrote:
>
>     Hi,
>
>     Thanks for the feedback.
>
>     > The intent here is to use a minimal PCRpt message, hence we explicitly 
> exclude SYMBOLIC-PATH-NAME TLV and RRO. ERO is kept empty for the same case.
>     > I think we have not precluded other TLVs from appearing in EOS to allow 
> future extensions.
>     > I do not think LSP-IDENTIFIERS TLV should be carried here, as it serves 
> no purpose and is not required -- section 7.3.1's MUST condition does not 
> trigger, as
>     > PLSP-ID=0 is a reserved value and does not identify an LSP.
>
>     Even if you think that LSP-ID should not be carried, it's not explicitly 
> mentioned in the draft, so it's authorized.
>     Why not restricting EOS to the minimal case, and let potential future 
> extensions to modify it ? To you forsee anycase that could require 
> modification of EOS content ?
>
>     At least the text should use normative words.
>
>     Best Regards,
>
>     Stephane
>
>     -----Original Message-----
>     From: Robert Varga [mailto:[email protected] <mailto:[email protected]>]
>     Sent: Monday, June 27, 2016 14:02
>     To: LITKOWSKI Stephane OBS/OINIS; [email protected] <mailto:[email protected]>
>     Subject: Re: [Pce] draft-ietf-pce-stateful-pce : clarifying the End Of 
> Synchronization marker
>
>     On 06/21/2016 05:18 PM, [email protected] 
> <mailto:[email protected]> wrote:
>     > Hi,
>     >
>     > Doing some interop testing between two vendors we falled into 
> misinterpretation of the current text of the End Of Sync marker content.
>     >
>     > Here is the current text :
>     >
>     > "The end of synchronization marker is a PCRpt message with the SYNC
>     >    Flag set to 0 for an LSP Object with PLSP-ID equal to the reserved
>     >    value 0 (see Section 7.3).  The LSP Object does not include the
>     >    SYMBOLIC-PATH-NAME TLV in this case, it will include an empty ERO as
>     >    its intended path and will not include the optional RRO object in the
>     >    path.  If the PCC has no state to synchronize, it will only send the
>     >    end of synchronization marker."
>     >
>     > The current text, IMO, has the following issues :
>     > - it uses non normative wording : "does not include", "will include" , 
> "will not include". How do we need to interpret it ? MUST, SHOULD, MAY ?
>     > - it does not precise if it can include or not some other objects : can 
> it include an LSP-Identifier object (with all fields to 0) ?
>
>     The intent here is to use a minimal PCRpt message, hence we explicitly 
> exclude SYMBOLIC-PATH-NAME TLV and RRO. ERO is kept empty for the same case.
>
>     I think we have not precluded other TLVs from appearing in EOS to allow 
> future extensions.
>
>     I do not think LSP-IDENTIFIERS TLV should be carried here, as it serves 
> no purpose and is not required -- section 7.3.1's MUST condition does not 
> trigger, as PLSP-ID=0 is a reserved value and does not identify an LSP.
>
>     > It would be good to enhance the text to better describe the content of 
> EOS.
>     >
>     > We suppose that in case there is an issue with the encoding of the EOS 
> marker, the following behavior will be applied, could you confirm ? 
> (typically bad encoding of EOS marker) :
>     > " The PCE does not send positive acknowledgements for properly received
>     >    synchronization messages.  It MUST respond with a PCErr message with
>     >    error-type 20 (LSP State Synchronization Error) and error-value 1
>     >    (indicating an error in processing the PCRpt) (see Section 8.5) if it
>     >    encounters a problem with the LSP State Report it received from the
>     >    PCC and it MUST terminate the session."
>
>     Yes. This would trigger, for example, for PLSP-ID=0 and non-empty ERO.
>
>     Bye,
>     Robert
>
>
>     
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