[Pals] Shepherd review of draft-ietf-l2vpn-vpls-pe-etree
Stewart Bryant <stbryant@cisco.com> Mon, 23 February 2015 15:47 UTC
Return-Path: <stbryant@cisco.com>
X-Original-To: pals@ietfa.amsl.com
Delivered-To: pals@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D00441A1B05; Mon, 23 Feb 2015 07:47:28 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -11.81
X-Spam-Level:
X-Spam-Status: No, score=-11.81 tagged_above=-999 required=5 tests=[BAYES_50=0.8, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_DKIM_WL=-7.5] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nxeSF0cGdhAJ; Mon, 23 Feb 2015 07:47:25 -0800 (PST)
Received: from aer-iport-4.cisco.com (aer-iport-4.cisco.com [173.38.203.54]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 0A55D1A1B5D; Mon, 23 Feb 2015 07:47:21 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=18998; q=dns/txt; s=iport; t=1424706442; x=1425916042; h=message-id:date:from:reply-to:mime-version:to:cc:subject; bh=k6ab4Rx+AL70QRFhwCS1DmBWk4NKvtrjsRGdGWn4u6w=; b=J8NvfqhUzqzw72N76ZRqZeN+mJw/AIOPuqLBduQgp/F2j5XGKDVb+7yN LYcuxknxSJq+UJxZvkaK+GsF/BWaPf02f0XUiZeSK0UP5+i9gFi5gXXwW 4aKOv7YgA4iLnCXjmK3zboLSVpRi/KqqRj+eM6NK4WNrwL+bNYzAc6344 8=;
X-IronPort-AV: E=Sophos;i="5.09,631,1418083200"; d="scan'208,217";a="353897059"
Received: from aer-iport-nat.cisco.com (HELO aer-core-4.cisco.com) ([173.38.203.22]) by aer-iport-4.cisco.com with ESMTP; 23 Feb 2015 15:47:20 +0000
Received: from [64.103.108.174] (dhcp-bdlk10-data-vlan301-64-103-108-174.cisco.com [64.103.108.174]) by aer-core-4.cisco.com (8.14.5/8.14.5) with ESMTP id t1NFlKw2019751; Mon, 23 Feb 2015 15:47:20 GMT
Message-ID: <54EB4B87.2080202@cisco.com>
Date: Mon, 23 Feb 2015 15:47:19 +0000
From: Stewart Bryant <stbryant@cisco.com>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.4.0
MIME-Version: 1.0
To: draft-ietf-l2vpn-vpls-pe-etree@tools.ietf.org, "pals@ietf.org" <pals@ietf.org>
Content-Type: multipart/alternative; boundary="------------050303010408060408060807"
Archived-At: <http://mailarchive.ietf.org/arch/msg/pals/_xR3R-h_ImCkLUI2f0WWhpn_HkY>
Cc: "l2vpn-chairs@tools.ietf.org" <l2vpn-chairs@tools.ietf.org>, bess-chairs@tools.ietf.org, pals-chairs@tools.ietf.org, "bess@ietf.org" <bess@ietf.org>
Subject: [Pals] Shepherd review of draft-ietf-l2vpn-vpls-pe-etree
X-BeenThere: pals@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: stbryant@cisco.com
List-Id: "Pseudowire And LDP-enabled Services dicussion list." <pals.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/pals>, <mailto:pals-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/pals/>
List-Post: <mailto:pals@ietf.org>
List-Help: <mailto:pals-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/pals>, <mailto:pals-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 23 Feb 2015 15:47:29 -0000
I have picked up the task of shepherding this draft, and have a number of comments which I think that you should address before we send this text to the IESG. As the text contains both LDP and BGP control information I am copying the BESS WG and their chairs. - Stewart ======== SB> The document fails I-D nits with Summary: 2 errors (**), 0 flaws (~~), 9 warnings (==), 1 comment (--). Please fix this. ====== SB> Number of authors. The guideline is five but it is not a hard limit provided that all authors made significant contribution. If asked by the IESG can all authors point to specific text that they wrote? Ethernet-Tree (E-Tree) Support in Virtual Private LAN Service (VPLS) draft-ietf-l2vpn-vpls-pe-etree-04.tx ===== Abstract A generic Virtual Private LAN Service (VPLS) solution is proposed for Ethernet-Tree (E-Tree) services which uses VLANs to indicate root or leaf traffic. A VPLS Provider Edge (PE) model is illustrated as an example for the solution. In the solution, E-Tree VPLS PEs are interconnected by PWs which carry the VLAN indicating the E-Tree attribute, the MAC address based Ethernet forwarding engine and the PW work in the same way as before. A signaling mechanism for E-Tree capability and VLAN mapping negotiation is further described. ====== 2. Terminology E-Tree: Ethernet Tree, a Rooted-Multipoint EVC service as defined in MEF 6.1 EVC: Ethernet Virtual Connection, as defined in MEF 4.0 FIB: Forwarding Information Base, or forwarding table T-VSI: Tree VSI, a VSI with E-Tree support Root AC, an AC attached with a root Leaf AC, an AC attached with a leaf C-VLAN, Customer VLAN S-VLAN, Service VLAN B-VLAN, Backbone VLAN Root VLAN, a VLAN ID used to indicate all the frames that are originated at a root AC Leaf VLAN, a VLAN ID used to indicate all the frames that are originated at a leaf AC I-SID, Backbone Service Instance Identifier, as defined in IEEE 802.1ah ======= 3. Introduction Further, an E-Tree service may include multiple roots and multiple leaves. Although VPMS or P2MP SB> VPMS, P2MP and in a few line VPLS, VSI and PE need expansion (and ideally a reference) ======== IEEE 802.1 has incorporated the generic E-Tree solution in the latest version of 802.1Q [802.1Q-2011], which is just an improvement on the traditional asymmetric VLAN mechanism (the use of different VLANs to indicate E-Tree root/leaf attributes and prohibiting leaf-to-leaf traffic with the help of VLANs was first standardized in IEEE 802.1Q- 2003). In the solution, VLANs are used to indicate root/leaf SB> In THE solution - which solution is THE solution? ======= This document introduces how the Ethernet VLAN solution can be used SB> s/introduces/specifies/ and later s/proposed/specified/ to support generic E-Tree services in VPLS. The solution proposed ======= here is fully compatible with the IEEE bridge architecture and the SB> s/the/with/ IETF PWE3 technology, thus it will not change the FIB (such as SB> please expand FIB ======= 4. PE Model with E-Tree Support Problem scenario of E-Tree as shown in Fig. 1 of [Etree-req] is a SB> The problem ======= 4.1. Existing PE Models SB> In the text that follows it is clear how Fig 1 fits into the picture but not Fig 2 (which as far as I can see you do not even reference). I think you are saying that Fig 2 is the existing VPLS model, then Fig 3 is the obvious mapping to E-tree, but there are problems, but this needs to be much clearer. ======== 4.2. A New PE Model with E-Tree Support In order to support the E-Tree in a more scalable way, a new VPLS PE model with a single Tree VSI (T-VSI, a VSI with E-Tree support) is proposed. SB> s/proposed/specified/ ======= For an S-VLAN tagged port, the S-VLAN tag in the Ethernet frames received from the root ACs SHOULD be translated to the root S-VLAN in the VPLS network domain. Alternatively, the PBB VPLS PE model (where SB> PBB needs expansion ======= In all cases, the outermost VLAN in the resulted Ethernet header is used to indicate the E-Tree attribute of an Ethernet frame; this document will use VLAN to refer to this outermost VLAN for simplicity SB> S/will use/uses/ 5. PW for E-Tree Support 5.1. PW Encapsulation To support an E-Tree service, T-VSIs in a VPLS must be interconnected with a bidirectional Ethernet PW. The Ethernet PW may work in the tagged mode (PW type 0x0004) as described in [RFC4448], and a VLAN tag must be carried in each frame in the PW to indicate the frame SB>s/and a VLAN tag must be carried in each frame/ in which case a VLAN tag MUST be carried in each frame/ originated from either root or leaf (the VLAN tag indicating the frame originated from either root or leaf can be translated by a bridge module in the PE or added by an outside Ethernet edge device, even by a customer device). In the tagged PW mode, two service delimiting VLANs must be allocated in the VPLS domain for an E-Tree. s/must/MUST/ ======= Raw PW (PW type 0x0005 in [RFC4448]) may be used to carry E-Tree service for a PW in Compatible mode as shown in Section 5.3.2. SB> I think this needs to be : Raw PW (PW type 0x0005 in [RFC4448]) MAY also be used ======== 6. Signaling for E-Tree Support 6.1. LDP Extensions for E-Tree Support In addition to the signaling procedures as specified in [RFC4447], this document proposes a new interface parameter sub-TLV to provision an E-Tree service and negotiate the VLAN mapping function, as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | E-Tree | Length=8 | Reserved |P|V| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Root VLAN ID | Leaf VLAN ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 8 E-Tree Sub-TLV Where: o E-Tree is the sub-TLV identifier to be assigned by IANA. SB> You have an assigned value. I think it would be clearer to all to say that and include the value in this text ======== A PE that receives a PW label mapping message with an E-Tree Sub-TLV from its peer PE, after saving the VLAN information for the PW, must SB> must or MUST? The latter I think. ========= SB> Does what follows need to be proceeded by Else or Otherwise? PW processing as described in [RFC4448] proceeds as usual for all cases. 6.2. BGP Extensions for E-Tree Support A PE which does not recognize this attribute shall ignore it silently. SB> I think that should be SHALL or MUST. ====== 7. OAM Considerations Ethernet OAM for E-Tree including both service OAM and segment OAM frames shall undergo the same VLAN mapping as the data traffic; and root VLAN SHOULD be applied to segment OAM frames so that they are not filtered. SB> I think s/shall/SHALL/ ======= 8. Applicability The solution is applicable to both LDP VPLS [RFC4762] and BGP VPLS SB> s/The/This/ or s/The solution specified in this document/ ====== 10. IANA Considerations IANA is requested to allocate a value for E-Tree in the registry of Pseudowire Interface Parameters Sub-TLV type. Parameter ID Length Description ======================================= TBD 8 E-Tree SB> Update to show you have the assignment ======= IANA is requested to allocate two new LDP status codes from the registry of name "STATUS CODE NAME SPACE". The following values are suggested: Range/Value E Description ------------- ----- ---------------------- TBD 1 E-Tree VLAN mapping not supported TBD 0 Leaf to Leaf PW released SB> Update to show you have the assignment ====== IANA is requested to allocate a value for E-Tree in the registry of BGP Extended Community. Type Value Name ======================================= TBD E-Tree Info SB> Update to show you have the assignment ======= Appendix A. Other PE Models for E-Tree A.1. A PE Model With a VSI and No bridge This PE model may be used by an MTU-s in an H-VPLS network, or an N- PE in an H-VPLS network with non-bridging edge devices, wherein a spoke PW can be treated as an AC in this model. SB> Please check that all of the above abbreviations have been previously expanded. =======
- Re: [Pals] Shepherd review of draft-ietf-l2vpn-vp… Stewart Bryant
- Re: [Pals] Shepherd review of draft-ietf-l2vpn-vp… Alexander Vainshtein
- Re: [Pals] Shepherd review of draft-ietf-l2vpn-vp… Jiangyuanlong
- Re: [Pals] Shepherd review of draft-ietf-l2vpn-vp… Alexander Vainshtein
- Re: [Pals] Shepherd review of draft-ietf-l2vpn-vp… Jiangyuanlong
- [Pals] Shepherd review of draft-ietf-l2vpn-vpls-p… Stewart Bryant
- Re: [Pals] Shepherd review of draft-ietf-l2vpn-vp… Jiangyuanlong