Re: New Version Notification for draft-jiang-l2vpn-evpn-etree-2vlan-00.txt

["Ali Sajassi (sajassi)" <[e-mail]>]

Jiangyuanlong,


Your proposal of applying vlan-tags (as done for VPLS) to E-VPN solution
is broken and doesn't work properly for E-VPN for the following reasons:

1) It breaks MPLS forwarding for egress PE - E-VPN allows for pure MPLS
forwarding at the egress PE

2) Even in scenarios where MAC lookup is used on egress PE, it creates
unnecessary overhead that is absolutely NOT needed. E-VPN multicast
packets already carries SH label (which as describe in etree-evpn draft)
is also used for root/leaf indication.


EVPN is the next gen solution which doesn't have the limitation of
existing vpls solution. It is extreemly flexible as it allows for pure
MPLS forwarding to a given AC without any MAC lookup (in either
direction). It allows for asymmetric MAC lookup operation (lookup in the
ingress PE but no lookup on the egress PE). Or it allows for lookup in
both directions. We don't want to contamiate such solution with the kludge
that we used for VPLS.

Cheers,
Ali 



On 9/21/12 7:31 PM, "Jiangyuanlong" <[e-mail]> wrote:

>Hi Giles,
>
>Perhaps the gauge of the consensus in the minutes was not so clear for me:
>"         Giles - are we agreed we want to get to one solution for VPLS
>and E-VPN.
>          Not many people.  But even fewer who want multiple.  Checked to
>see if
>          people want one solution only for E-VPN and VPLS - only a
>couple of hands."
>Nevertheless, E-VPN needs an E-Tree solution and it is the WG consensus
>to decide which way to take.
>
>Thanks,
>Yuanlong
>
>-----Original Message-----
>From: Giles Heron [mailto:[e-mail]]
>Sent: Friday, September 21, 2012 9:09 PM
>To: Jiangyuanlong
>Cc: [e-mail]
>Subject: Re: New Version Notification for
>draft-jiang-l2vpn-evpn-etree-2vlan-00.txt
>
>Thanks Yuanlong,
>
>however I must say that your memory of the IETF 84 L2VPN meeting differs
>from mine (and from what is noted in the minutes).  Whilst Himanshu said
>that it was better to have the same solution for VPLS and E-VPN, Ali
>stated that there was no benefit in the E-VPN case in using an additional
>tag (such as a VLAN).  No consensus was reached in the meeting.
>
>Giles
>
>On 21 Sep 2012, at 10:16, Jiangyuanlong <[e-mail]> wrote:
>
>> Hi all,
>> 
>> During the 84th IETF meeting, the group discussed the issue of E-Tree
>>in E-VPN, and it was shown that a single solution was more preferred
>>than two different approaches for VPLS and E-VPN.
>> This I-D probes how the 2VLAN approach can be used to support E-Tree in
>>E-VPN and it seems not a big issue.
>> Any comments from you are greatly appreciated.
>> 
>> Best regards,
>> Yuanlong
>> 
>> -----Original Message-----
>> From: [e-mail] [mailto:[e-mail]]
>> Sent: Friday, September 21, 2012 4:55 PM
>> To: Jiangyuanlong
>> Subject: New Version Notification for
>>draft-jiang-l2vpn-evpn-etree-2vlan-00.txt
>> 
>> 
>> A new version of I-D, draft-jiang-l2vpn-evpn-etree-2vlan-00.txt
>> has been successfully submitted by Yuanlong Jiang and posted to the
>> IETF repository.
>> 
>> Filename:	 draft-jiang-l2vpn-evpn-etree-2vlan
>> Revision:	 00
>> Title:		 E-Tree Support with 2VLAN in E-VPN
>> Creation date:	 2012-09-21
>> WG ID:		 Individual Submission
>> Number of pages: 6
>> URL:            
>>http://www.ietf.org/internet-drafts/draft-jiang-l2vpn-evpn-etree-2vlan-00
>>.txt
>> Status:         
>>http://datatracker.ietf.org/doc/draft-jiang-l2vpn-evpn-etree-2vlan
>> Htmlized:       
>>http://tools.ietf.org/html/draft-jiang-l2vpn-evpn-etree-2vlan-00
>> 
>> 
>> Abstract:
>>   This document discusses how the Dual-VLAN approach as described in
>>   [Etree-vlan] can be used to support the transport of E-Tree service
>>   in E-VPN. Thus a single convergent solution is possible for both VPLS
>>   and E-VPN.
>> 
>> 
>> 
>> 
>> The IETF Secretariat
>> 
>