Hi Quan, On Tue, Sep 24, 2024 at 1:11 PM <xiong.q...@zte.com.cn> wrote:
> > Hi Cheng, > > > Thanks for your suggestion! > > > Got it about the PSID. > > And I also agree with the P flag in LSP. So I suggest to clarify it and > the adding text may be as following shown. > > > 4.5. Path Attributes Object > > > The [I-D.ietf-pce-multipath] defines the PATH-ATTRIB object, which > carries > > per-path information and serves as a separator between multiple > ERO/RRO > > objects, enabling the encoding of multiple segment lists in a > Candidate > > Path, as described in [I-D.ietf-pce-segment-routing-policy-cp]. > The Path > > Segment TLV can be optionally included in the PATH-ATTRIB object to > > associate a segment list with the Path Segment Identifier(PSID). > It’s > > important to note that the Path Segment TLV in the PATH-ATTRIB object > > applies to the path (the immediately following ERO/RRO), whereas > the Path > > Segment TLV in the LSP object applies to all paths in the PCEP message. > > If the PSID is encoded in the PATH-ATTRIB object, it MUST be used to > > identify the SR path. The P flag in LSP Object is also used to indicate > > that the allocations of all PSIDs need to be done by the PCE. > > > Dhruv: Can I suggest changing the last sentence to make it generic - The usage of P flag in the LSP object for Path Segment as specified in Section 4.2 also applies to all PSIDs encoded in the PATH-ATTRIB object. And in section 4.2, you can remove " in the LSP object", to keep the text generic and thus apply to TLV in both LSP object and PATH-ATTRIB object. Thanks! Dhruv > Thanks, > > Quan > > > Original > *From: *ChengLi <c...@huawei.com> > *To: *熊泉00091065;dhruv.i...@gmail.com <dhruv.i...@gmail.com>; > *Cc: *pce@ietf.org <pce@ietf.org>;draft-ietf-pce-sr-path-segm...@ietf.org > <draft-ietf-pce-sr-path-segm...@ietf.org>; > *Date: *2024年09月23日 16:20 > *Subject: **RE: [Pce] Re: Path segment supporting multiple segment lists > in a candidate path* > > Hi Quan， > > > > PSID(Path Segment ID) was defined in RFC9545 originally, and introduced in > SRv6 draft, so it can apply to SR-MPLS and SRv6. > > > > Reusing P flag in LSP is better to me, make it as general, indicating PSID > allocation request, no matter where the Path Segment TLV will be encoded. > > > > My 2cents, > > Cheng > > > > > > *From:* xiong.q...@zte.com.cn <xiong.q...@zte.com.cn> > *Sent:* Monday, September 23, 2024 4:59 AM > *To:* dhruv.i...@gmail.com > *Cc:* Cheng Li <c...@huawei.com>; pce@ietf.org; > draft-ietf-pce-sr-path-segm...@ietf.org > *Subject:* Re: [Pce] Re: Path segment supporting multiple segment lists > in a candidate path > > > > Hi Dhruv, > > > > Thanks for your reply! > > > > I will take your suggestion for the new version. But I have two concerns. > > The PSID is defined as "SRv6 Path Segment Identifier" in > draft-ietf-spring-srv6-path-segment and it is not mentioned in this > documents , cause path segment should cover both SR-MPLS and SRv6. So I > suggest we still use the path segment instead of PSID. > > Another concern is that, for example, when we put multiple path segment > TLVs in multiple PATH-ATTRIB objects but none in LSP object in PCInitiate > message, we also need to indicate PCE or egress PCC to allocate the path > segment. There may be two options, reusing P flag in LSP object to indicate > all path segment TLVs or creating a new P flag in PATH-ATTRIB object > to indicate each path segment TLV. So I think we need to clarify it. > > > > What is your thoughts? Thanks! > > > > Best Regards, > > Quan > > > > > > Original > > *From: *DhruvDhody <dhruv.i...@gmail.com> > > *To: *Cheng Li <c.l=40huawei....@dmarc.ietf.org>; > > *Cc: *熊泉00091065;pce@ietf.org <pce@ietf.org>; > draft-ietf-pce-sr-path-segm...@ietf.org < > draft-ietf-pce-sr-path-segm...@ietf.org>; > > *Date: *2024年09月20日 20:15 > > *Subject: Re: [Pce] Re: Path segment supporting multiple segment lists in > a candidate path* > > Hi Cheng, Quan, > > > > On Fri, Sep 20, 2024 at 2:52 PM Cheng Li <c.l=40huawei....@dmarc.ietf.org> > wrote: > > Hi Quan, > > Thank you for proposing the text. Please see my comment below. > > Thanks, > > Cheng > > > > 4.5. Path Attributes Object > > > > The Path Attributes (PATH-ATTRIB) Object is used to carry per-path > > information and to act as a separator between several ERO/RRO objects > > as per [I-D.ietf-pce-multipath]. > > As per [RFC9545], a Path Segment can be used to uniquely identify a > > segment list or multiple segment lists in a candidate path or an SR > > policy. > > __OLD__ > > When a set of path segments are used to identify multiple > > segment lists, the Path Segment TLV as described in the > > Section 4.2.1, MUST be carried in the PATH-ATTRIB Object to indicate > > the per-SR-path information regarding the Path Segment identifier. > > __OLD__ > > [Cheng]This might be rephrased. My suggestion. > > When multiple ERO/RRO objects are included as per > [I-D.ietf-pce-multipath], to support multiple segment lists in an Candidate > Path [ref to SR policy draft], the Path Segment TLV as described in the > Section 4.2.1, MUST be carried in the PATH-ATTRIB Object to identify each > SR path associated with a segment list. > > > > Dhruv: This use of MUST here means that if a PATH-ATTRIB Object exists, > the Path Segment TLV MUST be encoded in it. But we want to do that only in > case when a different PSID is used by each segment list. > > > > > > The P flag in LSP Object is used to indicate that the allocation of all > path segments need to be done by the PCE. A Path Segment TLV encoded in > the LSP Object apply to all the ERO/RRO, while a Path Segment TLV encoded > in a PATH-ATTRIB Object only apply to its ERO. In the cases that all the > segment lists are sharing a same PSID, the Path Segment TLV can be carried > in the LSP Object or each PATH-ATTRIB Object, respectively. > > > > > > Dhruv: I am unsure why we need to highlight the P flag here. The rest of > the text makes sense if we set or unset the P flag. > > > > Here is my suggestion - > > > > The [I-D.ietf-pce-multipath] defines the PATH-ATTRIB object, which carries > per-path information and serves as a separator between multiple ERO/RRO > objects, enabling the encoding of multiple segment lists in a Candidate > Path, as described in [I-D.ietf-pce-segment-routing-policy-cp]. The Path > Segment TLV can be optionally included in the PATH-ATTRIB object to > associate a segment list with the PSID. It’s important to note that the > Path Segment TLV in the PATH-ATTRIB object applies to the path (the > immediately following ERO/RRO), whereas the Path Segment TLV in the LSP > object applies to all paths in the PCEP message. If the PSID is encoded in > the PATH-ATTRIB object, it MUST be used to identify the SR path. > > > > Thanks! > > Dhruv > > > > > > *From:* xiong.q...@zte.com.cn <xiong.q...@zte.com.cn> > *Sent:* Friday, September 20, 2024 10:59 AM > *To:* pce@ietf.org > *Cc:* draft-ietf-pce-sr-path-segm...@ietf.org > *Subject:* Path segment supporting multiple segment lists in a candidate > path > > > > > > Hi PCE WG, > > > > A new version has been submitted as per > https://www.ietf.org/archive/id/draft-ietf-pce-sr-path-segment-11.txt. > > > > But in case of supporting multiple segment lists in a candidate path, it > is required to add Path Segment TLV into Path Attributes Object as > different path segment may identify different segment list . And in order > to make it backward compatible to current implementation, it needs to allow > carrying the TLV in both LSP and PATH-ATTRIB object. So I suggest to add a > new section to describe this part of extension as following shown. > > > > > > 4.5. Path Attributes Object > > > > The Path Attributes (PATH-ATTRIB) Object is used to carry per-path > > information and to act as a separator between several ERO/RRO objects > > as per [I-D.ietf-pce-multipath]. > > > > As per [RFC9545], a Path Segment can be used to uniquely identify a > > segment list or multiple segment lists in a candidate path or an SR > > policy. When a set of path segments are used to identify multiple > > segment lists, the Path Segment TLV as described in the > > Section 4.2.1, MUST be carried in the PATH-ATTRIB Object to indicate > > the per-SR-path information regarding the Path Segment identifier. > > The P flag in LSP Object is used to indicate that the allocation of > > all path segments need to be done by the PCE. When one single path > > segment is used to identify all segment lists, the Path Segment TLV > > MAY be carried in the LSP Object or PATH-ATTRIB Object. But the Path > > Segment TLV MUST be ignored in the LSP Object when it is also > > included in the PATH-ATTRIB Object. > > > > What is your thoughts? Any comments and suggestions are welcome. Thanks! > > > > Best Regards, > > Quan > > > > > > _______________________________________________ > Pce mailing list -- pce@ietf.org > To unsubscribe send an email to pce-le...@ietf.org > > > > >
_______________________________________________ Pce mailing list -- pce@ietf.org To unsubscribe send an email to pce-le...@ietf.org
