Re: [Pce] Few comments/queries on draft-ietf-pce-pce-initiated-lsp-04

Hi,

On 10 June 2015 at 03:32, Venugopal Reddy K <venugopalreddyk@huawei.com>
wrote:

>  Hi, Everyone!
>
>
>
> Have few comments/queries on draft-ietf-pce-pce-initiated-lsp-04. Could
> you please clarify on below points:
>
>
>
>   Section 6
>
>   In case of PCEP session failure, control over PCE-initiated LSPs
>
>     reverts to the PCC at the expiration of the redelegation timeout.  At
>
>    this point, the LSP is an "orphan" until the expiration of the State
>
>    Timeout timer.  To obtain control of a PCE-initiated LSP, a PCE
>
>    (either the original or one of its backups) sends a PCInitiate
>
>    message, including just the SRP and LSP objects, and carrying the
>
>    PLSP-ID of the LSP it wants to take control of
>
> 1.       In case of Backup PCE, what is the trigger point to send
> PCInitiate message to take control of orphan PCE-initiated LSP? I am
> wondering how does a backup PCE come to know that some LSPs are orphaned?
>
I see two scenarios :
  1) Another PCEP Session is up , in that case it seems to imply that the
PCE(s) keep track of the LSPs it can manage and the liveliness of the other
PCEs.
   2) There is no other PCEP session, the PCC reconnects to another PCE, in
this case the PCE can try to take ownership of the Initiated, not delegated
LSPs

 While I believe 1) is an interesting architecture, I do not think the
protocol procedures should put such constraint to the PCE implementation,
so the second option you propose should be allowed.

>
>
> 2.       Another option would be, if PCC takes charge and delegate the
> orphaned PCE initiated LSPs to backup PCE based on the local policy?
>
>
>
I think this should be allowed, the text could be :

In case of PCEP session failure, control over PCE-initiated LSPs
reverts to the PCC at the expiration of the redelegation timeout.  At
this point, the PCC MAY delegate the LSP to another PCE. the LSP is an
"orphan" until the expiration of the State
Timeout timer.

Some coordination between PCEs is still needed, for the original PCE to
regain control over that LSP the current PCE must forfeit control over that
LSP.

In addition there is no Error to indicate to the PCE that he can't have the
delegation back, this should be added , for instance 24,4

LSP instantiation error, Requested delegation rejected, another PCE
has the delegation. (ideally allow the optional inclusion of the other
PCE SPEAKER-IDENTITY-ID for troubleshooting. it should be subject to
security policies)

>  Response will be appreciated.
>
>
>
> Thanks a lot.
>
>
>
> Regards,
>
> Venu
>
>
>
> Regards,
 Cyril

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