Re: [mpls] discussion on a common top for yang models related to MPLS

"Rajiv Asati (rajiva)" <> Tue, 09 February 2016 15:43 UTC

Return-Path: <>
Received: from localhost ( []) by (Postfix) with ESMTP id 715371A92A9 for <>; Tue, 9 Feb 2016 07:43:21 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -14.502
X-Spam-Status: No, score=-14.502 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, RP_MATCHES_RCVD=-0.001, SPF_PASS=-0.001, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id yVUcVcX1qPST for <>; Tue, 9 Feb 2016 07:43:19 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher DHE-RSA-SEED-SHA (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id ACC541ABB1A for <>; Tue, 9 Feb 2016 07:43:19 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple;;; l=6020; q=dns/txt; s=iport; t=1455032599; x=1456242199; h=from:to:subject:date:message-id:references:in-reply-to: content-id:content-transfer-encoding:mime-version; bh=L29BH9TPBC8F2EG8wEmuehpcxX8CUpwi2dvVKonXm+Q=; b=h4sLCsRSbC+uJv0NFmdyLlXln1e+grq3qgXleelHvqrvYlSfCBeFeEBG 4o9RuLQritSWxJQIe6AomPS1gxqpClg0v7VSxaJ7sXSxFtulPOxGjjbqX IvqZ03Fkt82mf32RAFrUYkMDCMQ8x55TUUqAfIy/fE1RY4XI6la1ArDcn Y=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-AV: E=Sophos;i="5.22,421,1449532800"; d="scan'208";a="235920893"
Received: from ([]) by with ESMTP/TLS/DHE-RSA-AES256-SHA; 09 Feb 2016 15:43:18 +0000
Received: from ( []) by (8.14.5/8.14.5) with ESMTP id u19FhIA6028581 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Tue, 9 Feb 2016 15:43:18 GMT
Received: from ( by ( with Microsoft SMTP Server (TLS) id 15.0.1104.5; Tue, 9 Feb 2016 09:43:08 -0600
Received: from ([]) by ([]) with mapi id 15.00.1104.009; Tue, 9 Feb 2016 09:43:08 -0600
From: "Rajiv Asati (rajiva)" <>
To: Loa Andersson <>, "" <>
Thread-Topic: [mpls] discussion on a common top for yang models related to MPLS
Thread-Index: AQHRYBGjmAajuar7MEGEhMtXtilAlZ8dixwAgAZmqIA=
Date: Tue, 09 Feb 2016 15:43:08 +0000
Message-ID: <>
References: <> <>
In-Reply-To: <>
Accept-Language: en-US
Content-Language: en-US
user-agent: Microsoft-MacOutlook/
x-ms-exchange-messagesentrepresentingtype: 1
x-ms-exchange-transport-fromentityheader: Hosted
x-originating-ip: []
Content-Type: text/plain; charset="utf-8"
Content-ID: <>
Content-Transfer-Encoding: base64
MIME-Version: 1.0
Archived-At: <>
Subject: Re: [mpls] discussion on a common top for yang models related to MPLS
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Multi-Protocol Label Switching WG <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 09 Feb 2016 15:43:21 -0000

My preference wasn’t quite clear in the previous email, so let me state it explicitly - (1), IMO, MPLS base should reside off the root, and for (2) it might be worth dividing the subsequent models as either non-routing or routing, given that MPLS control plane e.g. LDP would be routing dependent, whereas static LSP _could_ not be. 

For (2), a hierarchy something like his works out (where non-routing is nothing but MPLS base)

	MPLS Base
			Static LSP
			Static LSP
			Dynamic LSP - LDP, mLDP, RSVP-TE, 

However, it creates an interesting challenge for aligning the yang models and while keeping the hierarchy simple.

Is it worth having a focused team figuring out MPLS base staying off the root, whereas routing-dependent MPLS control plane protocols e.g. LDP staying off routing?

Rajiv Asati
Distinguished Engineer, Cisco

-----Original Message-----
From: Rajiv Asati <>
Date: Friday, February 5, 2016 at 8:58 AM
To: Loa Andersson <>, "" <>
Subject: Re: [mpls] discussion on a common top for yang models related to MPLS

>I definitely agree (co-author hat off, and user hat on). Avoiding duplication and doing better organization would indeed be a good thing to do.   
>1) If MPLS base model (and subsequent models - LDP, TE etc.) augments the (IP) routing/routing-protocol, then it might not well apply to GMPLS. Is there an existing thought-process on this topic? 
>Either ignore the above and have GMPLS argument mpls base model as is, or get MPLS base on an independent path (off of (IP) routing/routing-protocol) and work out the subsequent models.
>2) In terms of hierarchy, is the below envisioned?
>	MPLS base => Static LSP and dynamic LSP
>		MPLS static LSP => 
>		MPLS dynamic LSP => 	
>			LDP
>			mLDP (MP)
>			TE (RSVP-TE P2P)
>			TE (RSVP-TE P2MP)			    
>-----Original Message-----
>From: mpls <> on behalf of Loa Andersson <>
>Date: Friday, February 5, 2016 at 7:34 AM
>To: "" <>
>Subject: [mpls] discussion on a common top for yang models related to MPLS
>>We have had discussion among the MPLS, TEAS and CCAMP working group
>>chairs - but as individual contributors, with chair half off. We agree
>>that this discussion should be taken to the working group(s).
>>The YANG models for MPLS and GMPLS are quite rapidly taking shape. MPLS
>>and GMPLS technologies have traditionally been very close, but their
>>development has been a bit disjoint. For the YANG models we would like
>>to minimize duplication of models/work and think the structure should
>>have a common the top,  with specific technologies augmented below.
>>The structure in general as well as the YANG model at the common top
>>needs to be the generic and aligned across the output of at least
>>CCAMP, MPLS and TEAS working groups. There has been good work 
>>progressing on TE specifics, e.g., see draft-ietf-teas-yang-te, but
>>other areas remain. On the LDP side of the house draft-raza-mpls-
>>ldp-mldp-yang is rapidly progressing towards working group adoption.
>>The models defined in draft-saad-mpls-static-yang could serve as the
>>start on filling some of the remaining gaps; covering core xMPLS
>>definitions and static LSPs.  There are a number of ways to make the
>>structure intuitive and generic, and serve as a foundation for
>>technology specific models.  -- This effort can be viewed as the same
>>type of work that was done for TE, see draft-ietf-teas-yang-te.
>>We think it would be a good idea  if the authors and the  WG considers
>>how to structure xMPLS definitions and static LSPs models to best
>>foster common use across the different related models being worked on 
>>across  different WGs.
>>We are sending this mail in hopes of getting this discussion started.
>>Thank you,
>>Lou and Loa
>>Loa Andersson                        email:
>>Senior MPLS Expert                
>>Huawei Technologies (consultant)     phone: +46 739 81 21 64
>>mpls mailing list