Hi Stewart, Thank a lot for your exhaustive review, please see my comments in line. I also uploaded a new version to reflect all those changes: http://tools.ietf.org/html/draft-ietf-l2vpn-vpls-pe-etree-05
Best regards, Yuanlong From: Pals [mailto:[email protected]] On Behalf Of Stewart Bryant Sent: Monday, February 23, 2015 11:47 PM To: [email protected]; [email protected] Cc: [email protected]; [email protected]; [email protected]; [email protected] Subject: [Pals] Shepherd review of draft-ietf-l2vpn-vpls-pe-etree 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) [Yuanlong] done. ======== 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? [Yuanlong] The new IEEE 802.1Q 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 [Yuanlong] done. ======= here is fully compatible with the IEEE bridge architecture and the SB> s/the/with/ [Yuanlong] done. IETF PWE3 technology, thus it will not change the FIB (such as SB> please expand FIB [Yuanlong] done. ======= 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 [Yuanlong] done. ======= 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. [Yuanlong] both Figs are called out in the new texts now. ======== 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/ [Yuanlong] done. ======= 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 [Yuanlong] done. ======= 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/ [Yuanlong] done. 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/ [Yuanlong] done. 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/ [Yuanlong] done. ======= 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 [Yuanlong] done. ======== 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 [Yuanlong] done. ======== 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. [Yuanlong] done. ========= SB> Does what follows need to be proceeded by Else or Otherwise? [Yuanlong] Yes, the following should be processed in all cases. 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. [Yuanlong] Done. ====== 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/ [Yuanlong] Done. ======= 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/ [Yuanlong] Done. ====== 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 [Yuanlong] done. ======= 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 [Yuanlong] done. ====== 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 [Yuanlong] done. ======= 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. [Yuanlong] done. =======
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