[Pce] Re: Pending item for draft-ietf-pce-state-sync

[Dhruv Dhody <[e-mail]>]

Hi Samuel,

On Tue, Jul 9, 2024 at 12:30 PM Samuel Sidor (ssidor) <[e-mail]>
wrote:

> Hi Andrew, Dhruv,
>
>
>
> Proposed text looks fine to me.
>
>
>
> Do we also need to consider future result of discussion for controlled ID?
> E.g. if decision will be done to use Notification message for ID space
> advertisement, will we need to synchronize content of those on top of TLVs
> from Open object?
>
>
>

Personally, I consider controlled ID (and PCECC) to be out of scope of the
state-sync I-D. We can make that explicit in the I-D.
In future another specification can tackle it if there is a need and can
use the technique that you suggest.

Thanks!
Dhruv


> Thanks,
>
> Samuel
>
>
>
> *From:* Dhruv Dhody <[e-mail]>
> *Sent:* Tuesday, July 9, 2024 11:18 AM
> *To:* Andrew Stone (Nokia) <andrew.stone=[e-mail]>
> *Cc:* [e-mail]; [e-mail]; pce-chairs <
> [e-mail]>
> *Subject:* [Pce] Re: Pending item for draft-ietf-pce-state-sync
>
>
>
> Hi Andrew,
>
>
>
> On Mon, Jul 8, 2024 at 4:37 PM Andrew Stone (Nokia) <andrew.stone=
> [e-mail]> wrote:
>
> Hi Dhruv, PCE WG
>
>
>
> Thanks for bringing this up again. PcNotif object with an add/remove
> semantics is exactly what I was thinking about as well in terms of how to
> carry this. I think we could (later) expand this to PCC->PCE communication
> to permit on-the-fly updates/changes to PcOpen criteria to avoid requiring
> session flap should knobs be flipped. With that said, I do like the
> proposed scoping of this via notification type so that way delete mechanics
> can only be applied for state sync.
>
>
>
> Minor recommendation to clarify the PcNtf should be sent before StateSync
> / PcRpt messages:
>
>
>
> *On session establishment with a state-sync PCE, the PCE MUST also
> exchange*
>
> *notifications for each of the PCCs it already has a session*
>
> *established prior to State Synchronization described in section 3.2.*
>
>
>
>
>
> Dhruv: I suggest adding this here ->
>
>
>
>    *  Notification-value=1: Add PCC's Open Information.  On session
>       establishment with a PCC, a PCE with state-sync capability MUST
>       send this notification to other state-sync PCEs with the SPEAKER-
>       ENTITY-ID TLV with values that identify the PCC and any other TLVs
>       encoded in the OPEN object received from the PCC.  On session
>       establishment with a state-sync PCE, the PCE MUST also exchange
>       notifications for each of the PCCs it already has a session
>       established.  The PCE MUST exchange this notification prior to the
>       State Synchronization (described in Section 3.2).  Note that the
>       PCNtf can be used to carry multiple NOTIFICATION objects, one for
>       each PCC.  On receiving this notification, PCE adds the
>       information to its database.
>
>
>
>
>
> Overall text proposal looks good to me. I would assume this belongs in a
> 3.x section in the document.
>
>
>
>
>
> I suggest that this could be a subsection "3.5.1.  Information Received
> via Open Message from PCC"
>
>
>
> Thanks!
>
> Dhruv
>
>
>
>
>
> Only caveat I can see is there would be no mechanism to potentially carry
> flag values from the PcOpen object, however, there's currently no flags
> defined after all these years and I suspect if they ever were defined they
> likely may not be relevant for state sync anyways. Should it ever be
> required, it would be straight forward to define a new TLV for pce-state
> sync to carry that anyways. I do not think we need to handle this now.
>
>
>
> Thanks!
>
> Andrew
>
>
>
> *From: *Dhruv Dhody <[e-mail]>
> *Date: *Saturday, July 6, 2024 at 7:52 AM
> *To: *[e-mail] <
> [e-mail]>, Andrew Stone (Nokia) <
> [e-mail]>
> *Cc: *[e-mail] <[e-mail]>, pce-chairs <[e-mail]>
> *Subject: *Pending item for draft-ietf-pce-state-sync
>
>
>
> *CAUTION:* This is an external email. Please be very careful when
> clicking links or opening attachments. See the URL nok.it/ext for
> additional information.
>
>
>
> Hi,
>
> There has been one pending item in draft-ietf-pce-state-sync. During IETF
> 119, we discussed adding support for the PCE to send the information it received
> in the PCC's open message to the other state-sync PCEs.
>
> Here is my initial proposal of using a new notification type for this
> purpose. I have some initial text that authors and WG can consider. We
> can discuss this during IETF 120 as well if required.
>
> ---
>
> 3.5.1.  Information Received via Open Message from PCC
>
>    To ensure uniform information across all PCEs, each PCE needs to
>    relay the information it receives from the PCCs in the Open message
>    to other PCEs via the state-sync session.  This includes various PCC
>    capabilities and parameters such as Maximum Segment Identifier (SID)
>    Depth (MSD).
>
>    As per [RFC5440], the PCEP Notification message (PCNtf) can be sent
>    by a PCEP speaker to notify its peer of a specific event.  A PCE
>    should notify the other state-sync PCEs of the information it
>    receives from the PCCs open message.  Section 7.14 of [RFC5440]
>    specify the NOTIFICATION object.  This document adds a new
>    Notification-type=TBD6 (Inter-PCE State-sync) and two Notification-
>    values (Notification-value=1 (Add PCC's Open Information) and
>    Notification-value=2 (Remove PCC's Open Information)).
>
>    For Notification-type=TBD6, the NOTIFICATION object encodes the
>    SPEAKER-ENTITY-ID TLV and any other TLV that can be carried inside
>    the OPEN object as a way to signal the PCC's information it received
>    via the open message to other state-sync PCEs.
>
>    *  Notification-value=1: Add PCC's Open Information.  On session
>       establishment with a PCC, a PCE with state-sync capability MUST
>       send this notification to other state-sync PCEs with the SPEAKER-
>       ENTITY-ID TLV with values that identify the PCC and any other TLVs
>       encoded in the OPEN object received from the PCC.  On session
>       establishment with a state-sync PCE, the PCE MUST also exchange
>       notifications for each of the PCCs it already has a session
>       established.  Note that the PCNtf can be used to carry multiple
>       NOTIFICATION objects, one for each PCC.  On receiving this
>       notification, PCE adds the information to its database.
>
>    *  Notification-value=2: Remove PCC's Open Information.  On session
>       down with a PCC, a PCE with state-sync capability MUST send this
>       notification to other state-sync PCEs with the SPEAKER-ENTITY-ID
>       TLV with values that identify the PCC to remove the information
>       from the database.
>
>    A PCE may receive this Notification from multiple PCEs that a given
>    PCC has a session and can use a similar mechanism as described in
>    Section 3.4 to keep the freshest state.  In case of the termination
>    of state-sync session, this information is also cleaned up alongside
>    LSP-DB.
>
> ---
>
>
> Would this be a good way forward? Am I missing something? Is there any
> other proposal on the table?
>
> Thanks!
>
> Dhruv (no-hats!)
>
> _______________________________________________
> Pce mailing list -- [e-mail]
> To unsubscribe send an email to [e-mail]
>
>