RE: The status of the approaches to the E-Tree solution?

[David Allan I <[e-mail]>]

Yes, if the discussion was options on preserving CUSTOMER tag information, we did march off on a tangent.

Now I hate to be pedantic but when you wrote:
"The reference to 'double tagging' was talking about solution A above, since there is both the service VID that is coordinated with the customer, as well as the Etree VID which designates the source (root or leaf)"

I presume you meant "the customer VID is coordinated with the provider", "Not the service VID that is coordinated with the customer". The customer tag infers the ETREE instance for a VID based UNI. And the customer does not need to know the provider ETREE VIDs....the provider needs to know what tags the customer wants mapped to specific provider services....

Cheers
Dave




-----Original Message-----
From: Rogers, Josh [mailto:[e-mail]]
Sent: Wednesday, April 25, 2012 5:42 PM
To: Fedyk, Donald (Don); David Allan I; Daniel Cohn; [e-mail]
Subject: Re: The status of the approaches to the E-Tree solution?

Dave/Daniel/Lucy/Others Debating how many tags necessary when S-Tag preservation is desired,


I think you all may have gone off on a tangent here.  The original discussion was about how to deal with the situation where the S-Tag is preserved at a handoff (either an ENNI, or Service Multiplexed UNI)

I believe there were two suggestions, one was that you push on a 'ETREE'
tag (one of two values, for either a frame sourced from a root AC or another for a frame from a leaf AC), and the second solution was to 'map'.


Imagine the following topology:

+-----+  +-----+  +-----+  +-----+
| CE1 |--| PE1 |--| PE2 |--| CE2 |
+-----+  +-----+  +-----+  +-----+
            |        |
+-----+  +-----+  +-----+  +-----+
| CE3 |--| PE3 |--| PE4 |--| CE4 |
+-----+  +-----+  +-----+  +-----+

Where:

Site  Type  VLAN
CE1   Root  X
CE2   Leaf  2
CE3   Leaf  3
CE4   Leaf  3


So, there are a lot of SP's who are keen on the way many services can be handed to a customer on a single UNI, but coordinating a single VLAN per service, with the customer (MEF used to call this EVPL when it was many point to point services terminating on a single UNI).  So, imagine that we have two ETREE instances, and an internet service all terminating on a single UNI connecting to CE1.  We have negotiated VLAN ID's with the customer, and they are expecting to reach CE2 using VLAN 2, CE3 and CE4 using VLAN 3, and Internet service on VLAN 10.  As a frame from CE1 comes into PE1 destined for CE2 (so the customer has tagged it with VID 2), using the 2VLAN method, since this is coming from a root site, do we

a) place the Root S-Tag in front of VID 2, then ship it across, and pop off the ETREE S-Tag (some SP's wish to Pop the original customer tag VID 2 as well)

-or-

b) swap VID2 for the ETREE Root S-Tag, send the frame to PE2 where it will remove the S-Tag (and either push VID2 back on, or leave it off depending on SP preference)

The reference to 'double tagging' was talking about solution A above, since there is both the service VID that is coordinated with the customer, as well as the Etree VID which designates the source (root or leaf)


Hope that clears more than it confuses,
Josh



On 4/25/12 4:22 PM, "Fedyk, Donald (Don)"
<[e-mail]> wrote:

>Hi Dave
>
>Yes the only point I would add is Dual VLAN means One VID for Root and
>one VID for Leaf. Not two TAGs at a time on the frame but two allocated
>for the service.
>
>The confusing part is no doubt that Dual PWE/Dual VLAN comparison talks
>about Encapsulation Overhead as a VLAN Tag. While that is true in a PWE
>sense it is still a single VLAN Tag at a time in a Ethernet E-tree sense.
> The compelling driver for Dual VLAN is having a Etree service that
>works in many environments and the DUAL VLAN (really dual VLAN
>interface on a
>VSI) uses the same mechanism (one VID for root and one VID for Leaf at
>a
>time) as specified in the IEEE. In a pure Ethernet bridging world the
>VLAN TAGs for Etree are not typically an overhead since translation is
>used.
>
>Don
>
>-----Original Message-----
>From: [e-mail] [mailto:[e-mail]] On Behalf
>Of David Allan I
>Sent: Wednesday, April 25, 2012 5:05 PM
>To: Daniel Cohn; [e-mail]
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>OK I feel like I am digressing a fair distance from the actual
>problem.... But here goes:
>
>So the scenarios center around "how ETREE do you want to be?"....
>
>If the ACs are root/leaf, then if they are P2P (single ethernet end
>station attached to each AC) this is moot. ETREE semantics are enforced
>by the 2VID domain in the center of the example. If you assumed nodes
>A&B in the example were L2VPN PEs, the tagging and the PW tag
>imposition all happened at the same point in the network.
>
>If they are not simple P2P all the way to end systems and the objective
>is to avoid bridging between leaf "sites" but allowing intra-leaf-site
>connectivity then the leaves can be LANs but the root is not, such that
>I cannot bridge through the root. But all hosts at a given leaf site
>can see each other. So root Ethernet end systems are directly attached
>or two VIDs are used in the root site.
>
>If the objective is that there are multiple ethernet attached end
>stations at both the leaf and root sites, and the objective is to
>enforce
>L2 isolation everywhere then I need two VIDs extended to the end system
>attachement point in the local LANs by whatever means....
>
>And I do not see adding VLANs in any particular spot, simply selection
>of the VID and associated semantics where VIDs are translated. The
>actual point of S-tag imposition could be a PE, or cloud be a NID/CLE
>on the customer prem (more likely scenario here to extend OAM demarc to
>the prem), or some switch in a RAN downstream of the MPLS PE... blah
>blah blah. And if ETREE is extended into a customer site LAN and
>outside of the provider domain, then two C-tags would have to be used
>that mapped to S-tags at the PBN boundary...
>
>Make sense?
>Dave
>
>-----Original Message-----
>From: Daniel Cohn [mailto:[e-mail]]
>Sent: Wednesday, April 25, 2012 4:39 PM
>To: David Allan I; [e-mail]
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>Dave, but the ACs are root/leaf (that's what the whole vpls etree is
>about - see the reqt draft), so per the 2vlan draft the root/leaf vlan
>must be added.
>
>Thumb typed - please be tolerant
>
>David Allan I <[e-mail]> wrote:
>
>HI Daniel:
>
>In the example provided,
>
>"ingress VLAN ID <-> Etree Root/Leaf VID <-> Egress VID"
>                  A                       B
>
>the service is not ETREE in the domains of the ingress and egress VID.
>It is ELAN. SO there is no root/leaf attribute to shovel around. It
>would require two VIDs in each domain if the ETREE semantics were to be
>telescoped E2E.
>
>Otherwise it is a provisioning of the VID translation tables at the
>intermediate nodes (A&B that I've added to the picture) that would
>determine the VID values used in each domain. Or in the example above,
>what the ingress, Etree and egress VID values were.
>
>Cheers
>Dave
>
>-----Original Message-----
>From: [e-mail] [mailto:[e-mail]] On Behalf
>Of Daniel Cohn
>Sent: Wednesday, April 25, 2012 3:46 PM
>To: Lucy yong; Rogers, Josh; Shahram Davari; Lizhong Jin;
>[e-mail]; [e-mail]
>Cc: [e-mail]
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>And to this I asked how this mapping works - how does the egress pe
>recover the ingress vid when it gets the frame tagged with only the
>root/leaf vid? How can you convey the ingress vid plus the root/leaf
>attribute in the same number of bits?
>What am I missing?
>
>Daniel
>
>Thumb typed - please be tolerant
>
>Lucy yong <[e-mail]> wrote:
>
>Daniel,
>
>David Allen already explained the solution.
>
>From David:
>ingress VLAN ID <-> Etree Root/Leaf VID <-> Egress VID.
>
>Ingress VID does not have to equal Egress VID but regardless there is
>only ever one VID on a frame at a time.
>
>-end
>
>This works when customer makes ingress VLAN ID not equal to or equal to
>egress VLAN ID.
>
>Regards,
>Lucy
>
>-----Original Message-----
>From: [e-mail] [mailto:[e-mail]] On Behalf
>Of Daniel Cohn
>Sent: Wednesday, April 25, 2012 11:39 AM
>To: Lucy yong; Rogers, Josh; Shahram Davari; Lizhong Jin;
>[e-mail]; [e-mail]
>Cc: [e-mail]
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>Hi Lucy,
>
>The scenario we are discussing is not the E-Tree E-NNI, but a general
>scenario where frames arriving at the root or leaf AC  are already
>double tagged. In this case, the dual vlan solution cannot preserve the
>vlans without adding a third one, can it?
>
>Maybe Shahram can add details on the scenario he had in mind
>
>Thumb typed - please be tolerant
>
>Lucy yong <[e-mail]> wrote:
>
>Daniel,
>
>MEF has S-VLAN preservation attribute for ENNI only because there is no
>s-vlan at UNI. When an MEN connects to multiple ENNI interfaces, S-VALN
>preservation attribute is used. It applies to E-Tree as well.
>
>Regards,
>Lucy
>
>-----Original Message-----
>From: [e-mail] [mailto:[e-mail]] On Behalf
>Of Daniel Cohn
>Sent: Tuesday, April 24, 2012 2:12 AM
>To: Lucy yong; Rogers, Josh; Shahram Davari; Lizhong Jin;
>[e-mail]; [e-mail]
>Cc: [e-mail]
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>Lucy,
>
>even if the current MEF framework doesn't require s-vlan preservation,
>I believe it's to the industry's benefit to adopt a solution that is
>not constrained to a specific enni model that, like all things
>networking, is likely to evolve. Especially when such a solution is available.
>
>Daniel
>
>Thumb typed - please be tolerant
>
>Lucy yong <[e-mail]> wrote:
>
>Daniel,
>
>MEF has worked in ENNI interface for a long time with many service
>providers' inputs. It had a fair reason to assume S-VLAN over ENNI by
>then. It may open B-VLAN for the future. It is better for us not to
>discuss  a future framework here, because it will lead us to nowhere.
>Here, we want to extend VPLS in supporting E-Tree.
>
>Best Regards,
>Lucy
>
>From: [e-mail] [mailto:[e-mail]] On Behalf
>Of Daniel Cohn
>Sent: Sunday, April 22, 2012 7:34 AM
>To: Rogers, Josh; Shahram Davari; Lizhong Jin; [e-mail];
>[e-mail]
>Cc: [e-mail]
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>Shahram and all,
>
>This question already came up in our discussions - is it safe to assume
>that the VLAN tags at the E-NNI will always be according to the current
>MEF model? Or should we try to be as transparent as possible to user
>VLAN encapsulation at the E-NNI, to accommodate future frameworks?
>I believe that any approach that looks at user payload (in this case
>VLAN
>tag) to signal VPLS information (in this case root/leaf origin) is
>necessarily tied to specific assumptions on user payload encapsulation
>(in this case, that S-VLAN tag is "available" to encode root/leaf). I
>don't think this is a future-proof assumption, it's very likely that
>other network models will come up that require S-VLAN preservation,
>which in the 2-VLAN approach would necessitate adding a third VLAN-ID.
>
>Daniel
>
>From: Shahram Davari <[e-mail]<mailto:[e-mail]>>
>To: Lizhong Jin <[e-mail]<mailto:[e-mail]>>,
>"[e-mail]<mailto:[e-mail]>"
><[e-mail]<mailto:[e-mail]>>,
>"[e-mail]<mailto:Alexander.Vainshtein@ecitele.c
>om>
>"
><[e-mail]<mailto:Alexander.Vainshtein@ecitele.c
>om>
>>
>Cc: "[e-mail]<mailto:[e-mail]>"
><[e-mail]<mailto:[e-mail]>>
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>Hi,
>
>I also have a question regarding 2-VLAN. What if the customer traffic
>already has an S-VLAN? Do we need a 3rd VLAN to identify the L/R?
>
>Thx
>Shahram
>
>From: [e-mail]<mailto:[e-mail]>
>[mailto:[e-mail]] On Behalf Of Lizhong Jin
>Sent: Friday, April 20, 2012 9:38 AM
>To: [e-mail]<mailto:[e-mail]>;
>[e-mail]<mailto:[e-mail]
>m>
>Cc: [e-mail]<mailto:[e-mail]>
>Subject: RE: The status of the approaches to the E-Tree solution?
>
>Hi, all,
>The difference between 2-VLAN and CW approach is who will provide the
>R/L information, customer payload or PW? The customer payload will be
>always modified to carry R/L information in 2-VLAN approach, while PW
>with CW will carry R/L information for CW approach.
>I have a question with the 2-VLAN approach in H-VPLS where H-VPLS is
>accessed by VPWS as described in RFC4672 section 10.1.3. If VPWS is
>used to access H-VPLS, how could the PE on VPWS side adds VLAN to
>indicate R/L information?
>
>Thanks
>Lizhong
>
>> ------------------------------
>>
>> Message: 2
>> Date: Thu, 19 Apr 2012 04:38:36 +0000
>> From: Alexander Vainshtein
>> <[e-mail]<mailto:Alexander.Vainshtein@ecitele.
>> com>>
>> To: "Rogers, Josh"
>><[e-mail]<mailto:[e-mail]>>, Lucy yong
>>        <[e-mail]<mailto:[e-mail]>>, Daniel
>>Cohn <[e-mail]<mailto:[e-mail]>>, Sam Cao
>>        <[e-mail]<mailto:[e-mail]>>
>> Cc: "[e-mail]<mailto:[e-mail]>"
>> <[e-mail]<mailto:[e-mail]>>
>> Subject: RE: The status of the approaches to the E-Tree solution?
>> Message-ID:
>>
>> <[e-mail]<mail
>> t o:[e-mail]>>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Hi all,
>> I fully understand that that what I am going to say is not very
>>popular, but:
>>
>> IMO one of the advantages of the CW-based solution is that it is
>>orthogonal to usage (or non-usage) of P2MP PWs for effective delivery
>>of BUN traffic.
>>
>> Another advantage is preservation of full mesh of P2P PWs in a VPLS,
>>and, in a more generic way, localization of effects of changes in the
>>PE configuration.
>>
>> In particular, adding a Leaf AC to a PE that previously has been only
>>supporting Root ACs (or vice versa), removal of the last Leaf or last
>>Root AC from a PE that previously has been supporting a mix etc.
>>affect only the PE where this operation happens and not the rest of the PEs.
>>
>> As for the need for HW changes that have been mentioned as a main
>>disadvantage of the CW-based approach - I believe it strongly depends
>>on specific implementations. And some changes in the forwarding
>>process are required in any solution.
>>
>> My 2c,
>>     Sasha
>>
>>
>>
>> ________________________________________
>> From: [e-mail]<mailto:[e-mail]>
>> [[e-mail]<mailto:[e-mail]>] on behalf of
>> Rogers, Josh
>> [[e-mail]<mailto:[e-mail]>]
>> Sent: Wednesday, April 18, 2012 9:57 PM
>> To: Lucy yong; Daniel Cohn; Sam Cao
>> Cc: [e-mail]<mailto:[e-mail]>
>> Subject: Re: The status of the approaches to the E-Tree solution?
>>
>> Again, the P2MP situation throws me.  Is this something that is used
>> commonly?
>>
>> I'm under the impression that adding P2MP to any model results in a
>> more complex model.  Wether outside s-tag is used to differentiate,
>> or dedicated pw's are used for the same purpose, it seems both become
>> more complex.
>>
>> Gile's comparison slide still concisely captures the differences
>>between these methods, in my opinion.  I haven't seen any new ideas or
>>thoughts brought to the group in the past week or two on the subject.
>> I would hate for both proposed methods to die on the vine because we
>>couldn't decide between two methods that have nothing inherently wrong
>>with either.
>>
>> -Josh
>>
>>
>> On 4/18/12 1:53 PM, "Lucy yong"
>><[e-mail]<mailto:[e-mail]>> wrote:
>>
>>>Send this again.
>>>
>>>Two PW approach can be complex too if the VPLS instance for E-Tree
>>>uses P2P PW for unicast traffic and P2MP PW for broadcast and unknown
>>>unicast traffic, and some P2MP PWs for multicast traffic. It may
>>>double all of them.
>>>
>>>Lucy
>>>
>>>-----Original Message-----
>>>From: Daniel Cohn
>>>[mailto:[e-mail]<mailto:[e-mail]>]
>>>Sent: Wednesday, April 18, 2012 1:42 PM
>>>To: Lucy yong; Rogers, Josh; Sam Cao
>>>Cc: [e-mail]<mailto:[e-mail]>
>>>Subject: RE: The status of the approaches to the E-Tree solution?
>>>
>>>I think the first option its the natural way to go. How is the
>>>processing in this case more complex?
>>>
>>>Thumb typed - please be tolerant
>>>
>>>Lucy yong <[e-mail]<mailto:[e-mail]>> wrote:
>>>
>>>
>>>
>>>Snipped..
>>>
>>>Multi-PW - On ingress PE, frame is placed onto either a Leaf-only
>>>P2MP PW (for traffic coming from a leaf AC), or onto a Root/Leaf P2MP
>>>PW (for traffic coming from a root AC) [[LY]] Not that simple. You
>>>construct either two P2MP PWs to all other PEs and let egress PE
>>>performing filtering, or construct one P2MP PW to leaf-only PEs and
>>>two P2MP PWs to root and leaf PEs and let ingress PE perform
>>>forwarding and filtering. Both make node process complex.
>>>
>>>[[LY]] VPLS is built with the mechanism utilizing P2P and P2MP PW for
>>>delivering the frames to remote PEs. We should utilize them with the
>>>minimized changes. Dual VLAN solution is simpler than Dual PW.
>>>
>>>Regards,
>>>Lucy
>>>
>>>
>>>I see how 2VLAN is simpler when P2MP PW's are involved, I think.  I
>>>haven't had any first hand experience with P2MP PW's, however, so
>>>don't feel terribly strong about this objection.  Is this a real
>>>problem for others (now or in the future), or is this objection in
>>>the weeds?
>>>
>>>I'm not sure the 'additional complexity' is notable, or even relevant.
>>>I encourage others to speak up if they disagree, as P2MP PW is only
>>>conceptual to me, and I am unfamiliar with real-life use cases for it.
>>>
>>>Thanks,
>>>Josh
>>>
>>>
>>>
>>>On 4/18/12 10:30 AM, "Lucy yong"
>>><[e-mail]<mailto:[e-mail]>> wrote:
>>>
>>>>Please see inline.
>>>>
>>>>-----Original Message-----
>>>>From: Sam Cao
>>>>[mailto:[e-mail]<mailto:[e-mail]>]
>>>>Sent: Tuesday, April 17, 2012 7:14 AM
>>>>To: 'Daniel Cohn'; Lucy yong; 'Rogers, Josh'; 'Henderickx, Wim
>>>>(Wim)'; [e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:Alexander.Vainshtein@ecitele.
>>>>com>
>>>>Cc: [e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>
>>>>Subject: RE: The status of the approaches to the E-Tree solution?
>>>>
>>>>Yes, 2 pws are only needed between pes with both root and leaf acs
>>>>after improving Dual-PW approach. If consider P2MP, Dual-PW approach
>>>>setup 2 P2MP PWs if need. There is no difference between P2MP or
>>>>normal PW setup. But, can Leaf-ACs be bound to Root PE of P2MP PW?
>>>>
>>>>[[LY]] No, it makes complex in setting up P2MP PW. Should a PE with
>>>>both root and leaf ACs set up two or one P2MP PW to other PEs (some
>>>>PE have both root and leaf AC and some only have leaf ACs)?
>>>>Regards,
>>>>Lucy
>>>>
>>>>Regards,
>>>>
>>>>Yuqun (Sam) Cao
>>>>E-mail: [e-mail]<mailto:[e-mail]>
>>>>
>>>>
>>>>-----Original Message-----
>>>>From: Daniel Cohn
>>>>[mailto:[e-mail]<mailto:[e-mail]>]
>>>>Sent: Tuesday, April 17, 2012 4:56 PM
>>>>To: Lucy yong; Rogers, Josh; Henderickx, Wim (Wim);
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:Alexander.Vainshtein@ecitele.
>>>>com>; Sam Cao
>>>>Cc: [e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>
>>>>Subject: RE: The status of the approaches to the E-Tree solution?
>>>>
>>>>Adding Sam (as l2vpn@ is holding messages)
>>>>
>>>>DC
>>>>
>>>>-----Original Message-----
>>>>From: Lucy yong
>>>>[mailto:[e-mail]<mailto:[e-mail]>]
>>>>Sent: Tuesday, April 17, 2012 12:39 AM
>>>>To: Daniel Cohn; Rogers, Josh; Henderickx, Wim (Wim);
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:Alexander.Vainshtein@ecitele.
>>>>com>
>>>>Cc: [e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>;
>>>>[e-mail]<mailto:[e-mail]>
>>>>Subject: RE: The status of the approaches to the E-Tree solution?
>>>>
>>>>
>>>>Snipped,
>>>>
>>>>As we discussed extensively in the list, and as reflected in giles
>>>>slide, 2 pws are only needed between pes with both root and leaf
>>>>acs, which will typically be a small minority.
>>>>[[LY]] Don't know if the assumption is true. Even it is the case,
>>>>both approaches can benefit from it. I was off for a while and
>>>>captures some discussions now.
>>>>
>>>>Also as per giles slide, dual vlan can have scalability issues due
>>>>to additional lookup and double use of vlans in internal emulated
>>>>lan interface. Also there are potential backward compatibility
>>>>issues with silicon that doesn't support vlan mapping.
>>>>[[LY]] I was not in IETF83 meeting and wait on the meeting minutes.
>>>>I am not clear on all the issues. Could you be more specific? As I
>>>>mentioned in below, two PW approach makes VPLS transport
>>>>construction and packet forwarding more complex, I can see potential
>>>>backward compatibility issues with 2 PW solution.
>>>>
>>>>Regards,
>>>>Lucy
>>>>
>>>>Regards,
>>>>
>>>>Daniel
>>>>
>>>>Thumb typed - please be tolerant
>>>>
>>>>Lucy yong <[e-mail]<mailto:[e-mail]>> wrote:
>>>>
>>>>In my mind, the VLAN approach means dual vlan method.
>>>>
>>>>The main concern for CW approach is hardware support.
>>>>
>>>>Two PW approach can be complex too if the VPLS instance for E-Tree
>>>>uses P2P PW for unicast traffic and P2MP PW for broadcast and
>>>>unknown unicast traffic, and some P2MP PWs for multicast traffic. It
>>>>may double all of them.
>>>>
>>>>E-tree is an Ethernet service and there is already VLAN based
>>>>solution in IEEE, can we just utilize it without complicating VPLS
>>>>transport construction? This also makes interworking with Eth only
>>>>network easier.
>>>>
>>>>Cheers,
>>>>Lucy
>>>>
>>>>-----Original Message-----
>>>>From: Rogers, Josh
>>>>[mailto:[e-mail]<mailto:[e-mail]>]
>>>>Sent: Monday, April 16, 2012 8:35 AM
>>>>To: Lucy yong; Henderickx, Wim (Wim);
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:Alexander.Vainshtein@ecitel
>>>>e.c
>>>>om>'
>>>>Cc: '[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>'
>>>>Subject: RE: The status of the approaches to the E-Tree solution?
>>>>
>>>>I believe the initial question was in regard to the CW method.  Are
>>>>you saying that you no longer are interested in that method in
>>>>preference of the dual vlan method?
>>>>
>>>>
>>>>
>>>>Lucy yong <[e-mail]<mailto:[e-mail]>> wrote:
>>>>
>>>>
>>>>Agree with Wim. VLAN approach is the best solution for E-Tree.
>>>>
>>>>Lucy
>>>>
>>>>-----Original Message-----
>>>>From: [e-mail]<mailto:[e-mail]>
>>>>[mailto:[e-mail]<mailto:[e-mail]>] On
>>>>Behalf Of Henderickx, Wim (Wim)
>>>>Sent: Thursday, April 12, 2012 2:03 AM
>>>>To: '[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:Alexander.Vainshtein@ecitel
>>>>e.c
>>>>om>'
>>>>Cc: '[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>';
>>>>'[e-mail]<mailto:[e-mail]>'
>>>>Subject: Re: The status of the approaches to the E-Tree solution?
>>>>
>>>>The vlan approach is superior as it also works for eth only
>>>>networks, etc. On top some vendors indicate hw issues with the cw
>>>>approach. As such we have dropped more or less the cw approach.
>>>>
>>>>Cheers,
>>>>Wim
>>>>_________________
>>>>sent from blackberry
>>>>
>>>>----- Original Message -----
>>>>From: Giles Heron
>>>>[mailto:[e-mail]<mailto:[e-mail]>]
>>>>Sent: Thursday, April 12, 2012 08:22 AM
>>>>To: Simon Delord
>>>><[e-mail]<mailto:[e-mail]>>; Alexander
>>>>Vainshtein
>>>><[e-mail]<mailto:Alexander.Vainshtein@ecitel
>>>>e
>>>>.com>>
>>>>Cc: [e-mail]<mailto:[e-mail]>
>>>><[e-mail]<mailto:[e-mail]>>; Vladimir Kleiner
>>>><[e-mail]<mailto:[e-mail]>>;
>>>>Andrew Sergeev
>>>><[e-mail]<mailto:[e-mail]>>;
>>>>Idan Kaspit
>>>><[e-mail]<mailto:[e-mail]>>;
>>>>Mishael Wexler
>>>><[e-mail]<mailto:[e-mail]>>;
>>>>Rotem Cohen
>>>><[e-mail]<mailto:[e-mail]>>
>>>>Subject: Re: The status of the approaches to the E-Tree solution?
>>>>
>>>>Sorry - the "anonymous presentation" was mine.  I should possibly
>>>>have put in a third column on the CW approach.  And hopefully the
>>>>minutes will be posted soon.
>>>>
>>>>We had various discussions, as Simon stated, and consensus seemed to
>>>>be forming around the two alternatives of two PWEs or two VLANs.  I
>>>>believe three of the authors of the CW approach are also authors of
>>>>the two VLAN approach and one is also an author of the two PWE
>>>>approach. So perhaps it's best to let those four individuals say
>>>>which approach they prefer and why?
>>>>
>>>>Giles
>>>>
>>>>On 10/04/2012 00:45, "Simon Delord"
>>>><[e-mail]<mailto:[e-mail]>> wrote:
>>>>
>>>>> Hi Alexander,
>>>>>
>>>>> You are right, no discussion on the WG mailing list recently, but
>>>>> there have been substantial discussions among the authors of
>>>>> various solution drafts off the mailing list. As far as I know, no
>>>>> consensus yet before ietf83, not sure the progress in the Paris WG
>>>>> meeting. I think the CW approach has not been rejected by the WG
>>>>> yet, or the WG has not yet decided on which one to adopt.
>>>>>
>>>>> Simon
>>>>>
>>>>> 2012/4/8 Alexander Vainshtein
>>>>> <[e-mail]<mailto:Alexander.Vainshtein@ecit
>>>>> e
>>>>> le.com>>
>>>>>
>>>>>>  Hi all,
>>>>>>
>>>>>> Unfortunately I have not been able to attend the Paris IETF.
>>>>>>
>>>>>> However, looking up the L2VPN proceedings, I've found a short
>>>>>> anonymous presentation called "E-Tree Update"  (
>>>>>> http://www.ietf.org/proceedings/83/slides/slides-83-l2vpn-1.pptx).
>>>>>> This presentation discusses the differences of the E-Tree
>>>>>> approaches based on dedicated VLANs (as in
>>>>>> http://datatracker.ietf.org/doc/draft-cao-l2vpn-vpls-etree/?inclu
>>>>>> d
>>>>>> e_t
>>>>>> ext=1) and multiple PWs between the PEs (as in
>>>>>> http://datatracker.ietf.org/doc/draft-ram-l2vpn-etree-multiple-pw
>>>>>> /
>>>>>> ?in
>>>>>> clude_te
>>>>>> xt=1)
>>>>>> and completely ignores the solution based on usage of the CW in
>>>>>> the PWs connecting the PEs (as in
>>>>>> http://datatracker.ietf.org/doc/draft-key-l2vpn-vpls-etree/?inclu
>>>>>> d
>>>>>> e_t
>>>>>> ext=1
>>>>>> ).
>>>>>>
>>>>>>
>>>>>>
>>>>>> The Minutes of the Paris L2VPN session are not yet available, but
>>>>>> I wonder whether the WG has taken a decision to reject the
>>>>>> approach based on the CW usage? I do not remember any recent
>>>>>> discussion of this topic on the WG mailing list.
>>>>>>
>>>>>>
>>>>>>
>>>>>> Regards, and lots of thanks in advance,
>>>>>>
>>>>>> Sasha
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
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>> End of L2vpn Digest, Vol 95, Issue 25
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