Subject: [Lsr] advertising service segment information Fw:New Version Notification for draft-lz-lsr-igp-sr-service-segments-04.txt

From: <[email-masked]>
Date: Thu, 18 Feb 2021 17:47:29 +0800 (CST)

Hi All,

SR service programming provides a fine integrated solution for overlay and underlay. Extensions of BGP-LS have already been proposed to advertise service function information to the controller.

We believe that the all-BGP solution is feasible by configuring BGP sessions for the BGP-LS AF between the nodes with service functions and the node selected to have a BGP session with the controller. But in this way, BGP must be enabled and configured on each node with service functions and BGP session must be established.

A common scenario is that IGP is enabled on each node in the network to distributed SIDs and SID-related information within the domain and a small amout of nodes are connected to the controller/PCE via BGP-LS. And nodes with or connected to service functions may be intermediate nodes in the domain. 

So we think that advertising the service information via IGP can reduce the need to additionally enable and configure BGP on these nodes, and makes network operation and maintenance easier in the network with many service function nodes.

One concern is that the service segment information is not needed by every SR router in the domain. In OSPF, the preliminary idea is to use the method similar to the one introduced in draft-acee-lsr-ospf-transport-instance, by using remote OSPF neighbor, the service infomation(non-routing infomation) can only be delivered from service nodes to node selected to have a BGP session with the controller.  

As SR service programming is gradually deployed in the network, the deployment of its control plane becomes an important aspect. So we take it to the list to see if anyone is interested in the topic.

Comments, suggestions and questions are more than welcome.

Thanks,

Yao

原始邮件

发件人：[email-masked]
收件人：刘尧00165286;Yongqing Zhu;Zhang Zheng;Zheng Zhang;Zhu Yongqing;
日 期 ：2021年01月21日 17:43
主 题 ：New Version Notification for draft-lz-lsr-igp-sr-service-segments-04.txt

A new version of I-D, draft-lz-lsr-igp-sr-service-segments-04.txt
has been successfully submitted by Liu Yao and posted to the
IETF repository.
 
Name:        draft-lz-lsr-igp-sr-service-segments
Revision:    04
Title:        IGP Extensions for Segment Routing Service Segment
Document date:    2021-01-21
Group:        Individual Submission
Pages:        9
URL:            https://www.ietf.org/archive/id/draft-lz-lsr-igp-sr-service-segments-04.txt
Status:         https://datatracker.ietf.org/doc/draft-lz-lsr-igp-sr-service-segments/
Htmlized:       https://datatracker.ietf.org/doc/html/draft-lz-lsr-igp-sr-service-segments
Htmlized:       https://tools.ietf.org/html/draft-lz-lsr-igp-sr-service-segments-04
Diff:           https://www.ietf.org/rfcdiff?url2=draft-lz-lsr-igp-sr-service-segments-04
 
Abstract:
   This document defines extensions to the link-state routing protocols
   (IS-IS and OSPF) in order to carry service segment information via
   IGP.

 
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