Re: [Pce] 答复: Re: A question about RFC8281 PCE-initiated LSPs.

Thanks Adrian! This makes sense! Hope the authors of GMPLS draft could take
this up.

Regards,
Dhruv

On Wed, Jan 24, 2018 at 9:06 PM, Adrian Farrel <adrian@olddog.co.uk> wrote:

> So, I think Quan is asking how to use a PCInitiate message to cause the
> creation of a "co-routed" bidirectional LSP that is achieved in the
> signaling plane by a single Path/Resv exchange.
>
>
>
> That is *G*MPLS function, but an answer would still be useful.
>
>
>
> Now, on a PCReq you need the B-bit to tell the PCE to compute a
> bidirectional path. But what you should be looking at is the PCRep message.
> That is, how does the PCE indicate that a bidirectional path has been
> returned? And the answer is two points:
>
>
>
> 1. Since the requester asked for a bidirectional path, and since a path
> has been computed, the PCC has every right to assume that the path can be
> used for a bidirectional LSP.
>
>
>
> 2. The RP Object is present on the PCRep and also contains thee B-flag.
>
>
>
> Now, note that the PCInitiate most closely follows the PCRep. That is, it
> flows from PCE to PCC and indicates the path of the LSP to be set up.
>
>
>
> Now, the PCInitiate carries the SRP Object, not the RP Object (just like
> PCUpd message).
>
>
>
> There is a flags field in the SRP Object, but the only bit defined is in
> 8281 for LSP removal.
>
>
>
> So, to expand on Quan's question: how do we Update an LSP that was set up
> with the B-flag in the RP object, and how do we create an bidirectional LSP
> using PCInitiate message?
>
>
>
> It is fine if the answer is "This is GMPLS function that possibly should
> not have been in 5440, and we need to look at some additional work for
> GMPLS extensions for 8231 and 8281."
>
>
>
> draft-ietf-pce-pcep-stateful-pce-gmpls is a starting point and should,
> perhaps, define a B flag for the SRP on the PCUpd that would then also be
> available automatically on the PCInitiate.
>
>
>
> Yours ramblingly,
>
> Adrian
>
>
>
>
>
>
>
>
>
> *From:* Pce [mailto:pce-bounces@ietf.org] *On Behalf Of *
> xiong.quan@zte.com.cn
> *Sent:* 24 January 2018 09:21
> *To:* dhruv.dhody@huawei.com
> *Cc:* robert.varga@pantheon.tech; draft-barth-pce-association-
> bidir@ietf.org; hu.fangwei@relay.zte.com.cn; msiva@cisco.com; pce@ietf.org;
> edward.crabbe@gmail.com
> *Subject:* [Pce] 答复: Re: A question about RFC8281 PCE-initiated LSPs.
>
>
>
> Hi Dhruv,
>
>
> I agree PCInitiate message including the ASSOCIATION Object may create a
> new LSP.
>
> But it still need to create bi-directional LSP by two messages.
>
> In some scenario, like PTN, we need to establish a bi-directional LSP by
> one message of a PCE request.
>
> In my opinion, this is the requirement to create a bi-directional LSP by a
>  PCInitiate message.
>
>
> Thanks,
> Quan
>
>
>
> --------------------------------------------------------------------------------
>
> [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
> Re: [Pce] A question about RFC8281 PCE-initiated LSPs.
>
> --------------------------------------------------------------------------------
>
>
> To: "xiong.quan at zte.com.cn" <xiong.quan at zte.com.cn>,
> "draft-barth-pce-association-bidir at ietf.org"
> <draft-barth-pce-association-bidir at ietf.org>
> Subject: Re: [Pce] A question about RFC8281 PCE-initiated LSPs.
> From: Dhruv Dhody <dhruv.dhody at huawei.com>
> Date: Tue, 23 Jan 2018 11:21:15 +0000
> Accept-language: en-GB, zh-CN, en-US
> Archived-at: <https://mailarchive.ietf.org/arch/msg/pce/
> Vx2UV03boBu2HHvP4qWETgxHr90>
> Cc: "edward.crabbe at gmail.com" <edward.crabbe at gmail.com>, "inaminei
> at google.com" <inaminei at google.com>, "msiva at cisco.com" <msiva at
> cisco.com>, "robert.varga at pantheon.tech" <robert.varga at
> pantheon.tech>, "pce at ietf.org" <pce at ietf.org>, "hu.fangwei at
> relay.zte.com.cn" <hu.fangwei at relay.zte.com.cn>, "julien.meuric at
> orange.com" <julien.meuric at orange.com>, "jonathan.hardwick at
> metaswitch.com" <jonathan.hardwick at metaswitch.com>
> Delivered-to: pce at ietfa.amsl.com
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> 0029DC4E@zte.com.cn>
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> Thread-topic: [Pce] A question about RFC8281 PCE-initiated LSPs.
>
> --------------------------------------------------------------------------------
>
> Hi Quan,
>
>
>
> As per [1]:
>        A PCE initiating a new LSP, can include the association group
>    information.  This is done by including the ASSOCIATION Object in a
>
>    PCInitiate message.
>
>
>
> So when a new LSP is created by PCE, you could still indicate the
> association. The association is not limited to existing LSPs.
>
>
>
> Hope this helps! Let me know if I understood your question correctly!
>
>
>
> Regards,
>
> Dhruv
>
>
>
> [1] https://tools.ietf.org/html/draft-ietf-pce-association-
> group-04#section-5.2.1
>
>
>
> From: xiong.quan at zte.com.cn [mailto:xiong.quan <xiong.quan> at
> zte.com.cn]
> Sent: 23 January 2018 13:07
> To: Dhruv Dhody <dhruv.dhody at huawei.com>; draft-barth-pce-association-bidir
> at ietf.org
> Cc: edward.crabbe at gmail.com; inaminei at google.com; msiva at cisco.com;
> robert.varga at pantheon.tech; pce at ietf.org; hu.fangwei at
> relay.zte.com.cn; julien.meuric at orange.com; jonathan.hardwick at
> metaswitch.com
> Subject: Re: [Pce] A question about RFC8281 PCE-initiated LSPs.
>
>
>
> Hi Dhruv,
>
>
> Thank you for the reply!O(∩_∩)O~
>
> I agree two created PCE-initiated LSPs may be associated by ASSOCIATION
> object as discussed in draft-barth-pce-association-bidir.
>
> But if there is no LSP existed, how to request a bi-directional TE LSP
> from PCE in PCE initiated operation?
>
>
> Quan Xiong
>
> --------------------------------------------------------------------------------
>
> [Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
> Re: [Pce] A question about RFC8281 PCE-initiated LSPs.
>
> --------------------------------------------------------------------------------
>
>
> To: "xiong.quan at zte.com.cn" <xiong.quan at zte.com.cn>, "edward.crabbe
> at gmail.com" <edward.crabbe at gmail.com>, "inaminei at google.com"
> <inaminei at google.com>, "msiva at cisco.com" <msiva at cisco.com>,
> "robert.varga at pantheon.tech" <robert.varga at pantheon.tech>
> Subject: Re: [Pce] A question about RFC8281 PCE-initiated LSPs.
> From: Dhruv Dhody <dhruv.dhody at huawei.com>
> Date: Tue, 23 Jan 2018 03:28:27 +0000
> Accept-language: en-GB, en-US
> Archived-at: <https://mailarchive.ietf.org/arch/msg/pce/
> ryZRIHK4zGoqSAsxMFQetTWDjbY>
> Cc: "hu.fangwei at relay.zte.com.cn" <hu.fangwei at relay.zte.com.cn>,
> "pce at ietf.org" <pce at ietf.org>, "draft-barth-pce-association-bidir
> at ietf.org" <draft-barth-pce-association-bidir at ietf.org>
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> Thread-topic: [Pce] A question about RFC8281 PCE-initiated LSPs.
>
> --------------------------------------------------------------------------------
>
> Hi Quan,
>
>
>
> Check out -  https://datatracker.ietf.org/doc/draft-barth-pce-
> association-bidir/
>
> Authors are in cc, if you need to have further discussion!
>
>
>
> Thanks!
>
> Dhruv
>
>
>
> From: Pce [mailto:pce-bounces <pce-bounces> at ietf.org] On Behalf Of
> xiong.quan at zte.com.cn
> Sent: 23 January 2018 07:37
> To: edward.crabbe at gmail.com; inaminei at google.com; msiva at cisco.com;
> robert.varga at pantheon.tech
> Cc: hu.fangwei at relay.zte.com.cn; pce at ietf.org
> Subject: [Pce] A question about RFC8281 PCE-initiated LSPs.
>
>
>
> Hi all,
>
>
> I encountered a problem as following shown.O(∩_∩)O~
>
> As defined in RFC5440,the PCC-initiated LSPs creation uses the B bit in RP
> object of PCReq message to indicate the direction of the TE LSP.
> When set, the PCC requests a bi-directional TE LSP and when cleared, the
> TE LSP is unidirectional.
>
> And in stateful PCE, RFC8281 proposed the PCE-initiated LSPs and the PCE
> could send a PCInitiate message to the PCC to request the creation of an
> LSP.
> The PCInitiate message carry the Objects including SRP, LSP ,END-POINTS
> and ERO. But no B bit in SRP object.
>
> How to configure the direction of the TE LSP in PCE-initiated operation?
>
> Best Regards,
>
> Quan Xiong
>
>
>
>
>
> --------------------------------------------------------------------------------
>
>
> References:
> [Pce] A question about RFC8281 PCE-initiated LSPs.
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