Hi Jeff,
Many thanks for your review and comments! It is a good point.
The limitations including MSD and ERLD has been described in detail in RFC8662.
And I need to clarify this in my background. How about adding texts as
following shown.
"[RFC8662] proposes to use entropy labels for SR-MPLS networks and mutiple
<ELI, EL> pairs SHOULD be inserted in the SR-MPLS label stack. As specified in
section 7.2 [RFC8662], the criteria may be defined to decide the placement of
entropy labels at the ingress node. Multiple limitations MUST be taken into
account when inserting <ELI,EL> pairs including Entropy Readable Label Depth
(ERLD) and Maximum SID Depth (MSD) etc. The ERLD is defined as the number of
labels which means that the node will perform load-balancing using the ELI/EL
pairs. And each ELI/EL pair must be within the ERLD of the node. Moreover, in
an SR-MPLS network, the MSD defines the maximum number of any kind of labels
including SR labels and entropy labels and it is a limit when the ingress node
imposing ELI/EL pairs on the SR label stack."
"As described in [RFC8662], an external controller (e.g PCE) can also be used
to program a label stack on a SR node. MSD and ERLD information has been
advertised to the controller (which is done is outside the scope of this
document.) The controller may configure the Entropy Label Position (ELP)
including the number and the position of the ELI/ELs pairs which need to be
inserted into the SR label stack. The PCE as a controller could be used to
perform the TE path computation as well as ELP which is useful especially in
inter-domain scenarios. "
Regards,
Quan
原始邮件
发件人：JeffTantsura
收件人：熊泉00091065;
抄送人：[email protected];[email protected];[email protected];[email protected];[email protected];[email protected];[email protected];
日 期 ：2021年02月21日 09:40
主 题 ：Re: [Pce] [PCE]:New Version Notification for
draft-peng-pce-entropy-label-position-05.txt
Hi,
It is the job of ingress router to impose the SID(label) stack that would
include one or more pairs of ELI/EL. This is always a subject to MSD
limitations (per platform/per LC if applicable).
The draft is not discussing implications of these limitations , which I find
rather unfortunate.
Regards,Jeff
On Feb 20, 2021, at 00:15, [email protected] wrote:
Dear Dhruv,Stephane,Zhenbin Li,Tarek and WG,
I just submitted a new version of the draft-peng-pce-entropy-label-position-05.
This draft has been presented in IETF 106 and 107. Many thanks for your
comments and discussions.
First, I think we have the consensus that in case of inter-domain scenario, PCE
would be useful for computing both SR path and the placement of entropy labels.
We should propose a set of extensions for PCEP.
Second, I fully agree with that the ingress MUST support the capability of
inserting multiple ELI/ELs and it needs to advertise the capability to PCE. So
I think we should add the capability in OPEN message from PCC to PCE. In the
current version, we define the E bit for a PCC to indicate that it supports
the capability of inserting multiple ELI/EL pairs and and supports the results
of SR path with ELP from PCE. What is your suggestion? If the E bit is enough?
Or should we define the BGP/IGP extension?
Finally, thanks to Zhenbin, I need to clarify that the ELI/EL pairs are
calculated for a specific traffic flow but the placement of the ELI/EL pairs
are calculated for a SR-path. In our draft, we propose the PCEs perform
computation of SR-path with the the placement of the ELI/EL pairs and the value
of ELI/EL pairs are calculated at the ingress.
I look forward and appreciate any comment and suggestion from you.
Thanks,
Quan
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主 题 ：New Version Notification for draft-peng-pce-entropy-label-position-05.txt
A new version of I-D, draft-peng-pce-entropy-label-position-05.txt
has been successfully submitted by Quan Xiong and posted to the
IETF repository.
Name: draft-peng-pce-entropy-label-position
Revision: 05
Title: PCEP Extension for SR-MPLS Entropy Label Position
Document date: 2021-02-19
Group: Individual Submission
Pages: 9
URL:
https://www.ietf.org/archive/id/draft-peng-pce-entropy-label-position-05.txt
Status:
https://datatracker.ietf.org/doc/draft-peng-pce-entropy-label-position/
Htmlized:
https://datatracker.ietf.org/doc/html/draft-peng-pce-entropy-label-position
Htmlized:
https://tools.ietf.org/html/draft-peng-pce-entropy-label-position-05
Diff:
https://www.ietf.org/rfcdiff?url2=draft-peng-pce-entropy-label-position-05
Abstract:
This document proposes a set of extensions for PCEP to configure the
entropy label position for SR-MPLS networks.
Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.
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