Thank you Adrian for the review comments. Please see inline with <RG>...

On Mon, Jan 20, 2020 at 2:32 PM Adrian Farrel <[email protected]> wrote:

> Hey Julien, WG,
>
> I have reviewed draft-li-pce-sr-bidir-path as part of the adoption poll
> and I have a few comments below.
>
> Overall, this seems like a simple combination of two existing functions:
> - associated bidirectional
> - SR
> So it should be straightforward and the function is clearly needed, and
> the working group should adopt it if there is enough support.
>
> Thanks,
> Adrian
>
> ===
>
> Please (please, please) could author teams sort out their front page
> author list before requesting WG adoption. If the authors don't reduce
> themselves to a maximum of five, the chairs will have to do it, and I
> don't think anyone wants that!
>
> ---
>
> Abstract
>
>    This document defines PCEP extensions for grouping two reverse
>    unidirectional SR Paths into an Associated Bidirectional SR Path when
>    using a Stateful PCE for both PCE-Initiated and PCC-Initiated LSPs as
>    well as when using a Stateless PCE.
>
> I don't think it is "two reverse unidirectional SR paths". One of them
> is normal and the other is reverse. So how about...
>
>    This document defines PCEP extensions for grouping two unidirectional
>    SR Paths (one in each direction in the network) into a single
>    Associated Bidirectional SR Path.  The mechanisms defined in this
>    document can also be applied using a Stateful PCE for both PCE-
>    Initiated and PCC-Initiated LSPs, as well as when using a Stateless
>    PCE.
>
> ---
>

<RG> Ack.


> Section 1
>
> s/SR supports to steer packets/SR supports steering packets/
>
> ---
>

<RG> Ack.


> Section 1
>
>    Currently, SR networks only support unidirectional paths.  However,
>    bidirectional SR Paths are required in some networks, for example, in
>    mobile backhaul transport networks.  The requirement of bidirectional
>    SR Path is specified in [I-D.ietf-spring-mpls-path-segment].
>
> I suggest...
>
>    SR is specified for unidirectional paths.  However, some applications
>    require bidirectional paths in SR networks, for example, in mobile
>    backhaul transport networks.  The requirement for bidirectional
>    SR Paths is specified in [I-D.ietf-spring-mpls-path-segment].
>
> ---
>

<RG. Ack.


> Section 1
>
> OLD
>    [I-D.ietf-pce-association-bidir] defines PCEP extensions for grouping
>    two reverse unidirectional MPLS TE LSPs into an Associated
>    Bidirectional LSP when using a Stateful PCE for both PCE-Initiated
>    and PCC-Initiated LSPs as well as when using a Stateless PCE.
> NEW
>    [I-D.ietf-pce-association-bidir] defines PCEP extensions for grouping
>    two unidirectional MPLS TE LSPs into an Associated Bidirectional LSP
>    when using a Stateful PCE for both PCE-Initiated and PCC-Initiated
>    LSPs as well as when using a Stateless PCE.
> END
>
> ---
>

<RG> Ack.


> 3.1 and 7.1
>
> Why do you need a new Association Type?
> If draft-ietf-pce-association-bidir was changes as:
> OLD
>    Value Name                                            Reference
>    ---------------------------------------------------------------------
>    TBD1 Single-sided Bidirectional LSP Association Group [This document]
>    TBD2 Double-sided Bidirectional LSP Association Group [This document]
> NEW
>    Value Name                                            Reference
>    ---------------------------------------------------------------------
>    TBD1 Single-sided Bidirectional Association Group [This document]
>    TBD2 Double-sided Bidirectional Association Group [This document]
> END
> ....then you could use the second of these for your use case. The type of
> path being associated would/should be the same for both paths in the
> association (but maybe there would be a future case with an LSP in one
> direction and an SR path in the other direction? but see section 5.3)
> and the type of path known from the PCEP message.
>
> ---
>

<RG> There was an email discussion on this topic on the list. Please see
following threads. Please let us know if you have additional thoughts on
this.

https://mailarchive.ietf.org/arch/msg/pce/LnTR_PfHlNG4BRyKLvkQuGdAmbU

https://mailarchive.ietf.org/arch/msg/pce/APYWjr7vzXsHkD9Sj3G6Y_cNYwg



>
> Section 5
>
>    The PCE SHOULD inform the reverse SR Paths to
>    the ingress PCCs and vice versa.
>
> Under what circumstance MAY the PCE choose to not do this?
>
> ---
>

<RG> OAM use-cases require reverse path but simple traffic steering
use-case on co-routed path on two ingress nodes may not need to know the
reverse SR path. Not sure if this SHOULD be MUST.


>
> 5.3 and 7.2
>
> Depending on how you handle the point for 3.1, you may need to fine tune
> this error code.  One way approach might be to make a change to
> draft-ietf-pce-association-bidir as:
> OLD
>    Error Type  Description                              Reference
>    -------------------------------------------------------------------
>     29         Association Error
>
>                Error value: TBD2                        This document
>                Bidirectional LSP Association -
>                Path Setup Type Mismatch
> NEW
>    Error Type  Description                              Reference
>    -------------------------------------------------------------------
>     29         Association Error
>
>                Error value: TBD2                        This document
>                Bidirectional Association -
>                Path Setup Type Mismatch
> END
>
> ---
>

<RG> Ok, will change the names in draft-ietf-pce-association-bidir.


> Having made the suggestions for 3.1 and 5.3, I wonder how much is
> different from draft-ietf-pce-association-bidir. Is this just a small
> explanation of the use of that draft in the SR network
>
> ---
>
> You should explicitly reference the figures (by name) from the text.
>
> ---
>
<RG> Ack.


> Thanks for Section 6. I find it really helpful.
>
> ---
>

<RG> Thanks Adrian.

Regards,
Rakesh



> -----Original Message-----
> From: Pce <[email protected]> On Behalf Of [email protected]
> Sent: 17 January 2020 10:13
> To: [email protected]
> Subject: [Pce] Adoption of draft-li-pce-sr-bidir-path-06?
>
> Hi all,
>
> It is time to share your thoughts about draft-li-pce-sr-bidir-path-06.
> Do you believe the I-D is a right foundation for a PCE WG item? Please
> use the PCE mailing list to express your comments, support or
> disagreement, including applicable rationale, especially for the latter.
>
> Thanks,
>
> Dhruv & Julien
>
>
>
> _______________________________________________
> Pce mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/pce
>
_______________________________________________
Pce mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/pce

Reply via email to