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
