Hi John,
If you can tolerate indefinite forwarding loop during transiet time, i have no 
problem. If the community think it is a serious problem, i think we must 
propose an applicable solution for it, maybe there are other solutions better 
than handshaking mechanism.

Thanks,
weiguo

________________________________________
From: John E Drake [[email protected]]
Sent: Friday, March 27, 2015 23:22
To: Haoweiguo; Rabadan, Jorge (Jorge); Satya Mohanty (satyamoh); EXT - 
[email protected]; [email protected]
Subject: RE: [bess] Handshaking among PEs in an EVPN ES based on Paxos algorithm

I think we have beaten this topic to death.  For the numerous reason I've 
given, I'm not interested in you proposal.

Yours Irrespectively,

John

> -----Original Message-----
> From: BESS [mailto:[email protected]] On Behalf Of Haoweiguo
> Sent: Friday, March 27, 2015 11:12 AM
> To: Rabadan, Jorge (Jorge); Satya Mohanty (satyamoh); EXT -
> [email protected]; [email protected]
> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos
> algorithm
>
> Hi Jorge,
> Let give you another indefinitely forwarding loop case, the picture is as
> follows:
>
> CE3------------CE4
>   |                        |
> PE3                   PE4
>
>
>
> PE1                   PE2
>  |                         |
> CE1------------CE2
>
> If PE1 and PE2 are dual DF PE in transiet time, assuing PE3 and PE4 are in
> stable state ,PE3 is DF PE, PE4 is non-DF PE, the BUM traffic from CE3 to CE1,
> the forwarding loop path is as follows;
> CE3--->PE3------>PE2--->CE2---->CE1---->PE1---->PE3-->CE3-->CE4--->PE4----
> >forever......
>
> Do you think the harm is enough?
> Thanks,
> weiguo
> ________________________________________
> From: Rabadan, Jorge (Jorge) [[email protected]]
> Sent: Friday, March 27, 2015 22:59
> To: Haoweiguo; Satya Mohanty (satyamoh); [email protected];
> [email protected]
> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos
> algorithm
>
> Hi Weiguo,
>
> OK, thanks for clarifying, that is the part I did not understand in your loop 
> :-)
>
> To me a loop means you send a frame and that frame keeps being forwarded
> by the same nodes indefinitely till you take a corrective action.
> In this case, CE3 might get a few packets during the transient state, but 
> those
> packets will have its own MAC SA so CE3 will discard them. I don't think that 
> is
> harmful for CE3 in most of the cases. And if it is, you just need to make sure
> the timers are long enough and the DF election properly implemented to
> avoid the transient DF-DF state.
>
> The handshaking is definitely overkilling IMHO.
>
> Thanks.
> Jorge
>
> -----Original Message-----
> From: Haoweiguo <[email protected]>
> Date: Friday, March 27, 2015 at 7:29 AM
> To: Jorge Rabadan <[email protected]>, "Satya Mohanty
> (satyamoh)" <[email protected]>, "[email protected]"
> <[email protected]>, "[email protected]" <[email protected]>
> Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos
> algorithm
>
> >Hi Jorge,
> >Sorry, maybe i have not explain clearly, pls allow me to clarify it
> >more clearly.
> >In MHN case, assuming CE1 and CE2 are multti-homed to PE1 and PE2, CE2
> >is single homed to remote PE3. CE1 and CE2 forms one layer 2 network,
> >so it multi-homed network scenario.
> >           CE3
> >             |
> >            PE3
> >
> >
> >PE1                  PE2
> >  |                       |
> >CE1-----------CE2
> >
> >In transiet period, PE1 and PE2 are both DF PE. At this time, CE3 sends
> >BUM traffic to CE1, the traffic will reach PE1 and PE2, CE1 will
> >receive two copy of the traffic from CE3, also loop is formed, the form path:
> >
> >CE3---->PE3---->PE2---->CE2---->CE1---->PE1--->PE3--->CE3
> >
> >I think the traffic loop is absolutely not allowed. In MHN case, the
> >loop will formed due to dual-DF PE in transiet period.
> >
> >Thanks,
> >weiguo
> >
> >
> >
> >________________________________________
> >From: Rabadan, Jorge (Jorge) [[email protected]]
> >Sent: Friday, March 27, 2015 20:26
> >To: Haoweiguo; Satya Mohanty (satyamoh); [email protected];
> >[email protected]
> >Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos
> >algorithm
> >
> >Hi Weiguo,
> >
> >About this:
> >
> >[weiguo]: Traffic duplication and loop issue both exist in dual DF PE
> >case. In multi-homed device case, say CE1 is multi-homed to PE1 and PE2
> >and both PE are DF PE. When CE1 sends traffic to PE1, the traffic will
> >loop back to CE1 through PE2. If CE1 can filter and drop the traffic ,
> >it is fortunate, maybe no loop.
> >For multi-homed network scenario, say local network1(CE1 and CE2) is
> >multi-homed to PE1 and PE2. Similarly, the traffic from CE1 will loop
> >back through PE1-->PE2-->CE2, it is very serious. It is absolutely not 
> >allowed.
> >
> >
> >[JORGE] In a MH device case: CE1->BUM->PE1->(ESI-label+BUM)->PE2. PE2
> >will not send the traffic back to CE1 due to the ESI-label and
> >split-horizon procedures.
> >In MH network case PE2 will NOT send the traffic to CE2 for the same
> >reason.
> >
> >Let me know if you disagree please.
> >
> >Thanks.
> >Jorge
> >
> >-----Original Message-----
> >From: Haoweiguo <[email protected]>
> >Date: Thursday, March 26, 2015 at 9:55 PM
> >To: "Satya Mohanty (satyamoh)" <[email protected]>,
> >"[email protected]" <[email protected]>,
> "[email protected]"
> ><[email protected]>
> >Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos
> >algorithm
> >
> >>Hi Satya,
> >>Pls see inline.
> >>
> >>Thanks,
> >>weiguo
> >>
> >>________________________________________
> >>From: Satya Mohanty (satyamoh) [[email protected]]
> >>Sent: Friday, March 27, 2015 12:11
> >>To: Haoweiguo; [email protected]; [email protected]
> >>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on Paxos
> >>algorithm
> >>
> >>Thomas,
> >>
> >>Thanks for your summary. It captures the essence of the discussion.
> >>[weiguo]: Yes, i agree.
> >>
> >>One feature of the HRW scheme is that it computes the Active and the
> >>Backup DF upfront.
> >>Whenever the Active PE, say PE1, dies; the Backup PE, PE2, can become
> >>the Active immediately upon receiving the withdraw of the ES route
> >>from PE1.
> >>It need not even have to wait for the 3 seconds time.
> >>[weiguo]: I think maybe your negligence, dies PE1 can't send withdraw
> >>message:) But when PE1 leaves ESI, it can withdraw the ES route
> >>immediately.
> >>When PE1 dies and recovers, assuming PE1 is DF PE, then PE1 and PE2
> >>will both act as PE for some transiet time.
> >>
> >>On the other hand, the 3 second timer will serve as a bulk and batch
> >>mechanism for the case when new PE(s) is(are) coming up, so we don¹t
> >>have to do a DF election ever so often.
> >>
> >>Haoweiguo,  I think the "loop" scenario is speculative.
> >>I think everybody understands that, yes, there may be some transient
> >>duplication of bum traffic; however, there is no "loop" problem to be
> >>solved.
> >>[weiguo]: Traffic duplication and loop issue both exist in dual DF PE
> >>case. In multi-homed device case, say CE1 is multi-homed to PE1 and
> >>PE2 and both PE are DF PE. When CE1 sends traffic to PE1, the traffic
> >>will loop back to CE1 through PE2. If CE1 can filter and drop the
> >>traffic , it is fortunate, maybe no loop.
> >>For multi-homed network scenario, say local network1(CE1 and CE2) is
> >>multi-homed to PE1 and PE2. Similarly, the traffic from CE1 will loop
> >>back through PE1-->PE2-->CE2, it is very serious. It is absolutely not
> >>allowed.
> >>
> >>Thanks,
> >>--Satya
> >>
> >>
> >>
> >>On 3/26/15 9:08 PM, "Haoweiguo" <[email protected]> wrote:
> >>
> >>>Hi Thomas,
> >>>I know you are neutral, sorry for my reply vulnerable to be
> >>>miunderstood.
> >>>
> >>>Thanks,
> >>>weiguo
> >>>
> >>>________________________________________
> >>>From: [email protected] [[email protected]]
> >>>Sent: Friday, March 27, 2015 11:59
> >>>To: Haoweiguo; [email protected]
> >>>Subject: Re: [bess] Handshaking among PEs in an EVPN ES based on
> >>>Paxos algorithm
> >>>
> >>>Hi Weiguo,
> >>>
> >>>2015-03-26, Haoweiguo:
> >>> > Thomas:
> >>>> > - RFC7432 may have transient periods where the DF election state
> >>>> > is not yet synchronized between the two peers:
> >>> >
> >>>> [weiguo]: Yes, i think RFC 7432 has transient periods of traffic
> >>>> loop
> >>>
> >>>Note well that I didn't write that there can be transient _loops_ .
> >>>I tried to capture the exchange you had all, and what I gather is
> >>>that the split-horizon procedure _prevents_loops_, independently of
> >>>any transient period where DF state is not synchronized and which may
> >>>lead to transient _duplicates_.
> >>>
> >>>-Thomas
> >>>
> >>>>
> >>>> 26/03/2015 20:05, John E Drake :
> >>>>>
> >>>>> Weiguo,
> >>>>>
> >>>>> I guess I wasn¹t clear.  I think you draft, for the reasons I have
> >>>>> detailed, is a non-solution to a non-problem with tremendous
> >>>>> control plane cost.
> >>>>>
> >>>>> Yours Irrespectively,
> >>>>>
> >>>>> John
> >>>>>
> >>>>> *From:*Haoweiguo [mailto:[email protected]]
> >>>>> *Sent:* Thursday, March 26, 2015 6:17 PM
> >>>>> *To:* John E Drake; Patrice Brissette (pbrisset)
> >>>>> *Cc:* Ali Sajassi (sajassi); [email protected]
> >>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on
> >>>>> Paxos algorithm
> >>>>>
> >>>>> Pls see below.
> >>>>>
> >>>>> Thanks,
> >>>>>
> >>>>> weiguo
> >>>>>
> >>>>>
> >>>>>-------------------------------------------------------------------
> >>>>>---
> >>>>>-
> >>>>>-
> >>>>>
> >>>>> *From:*John E Drake [[email protected]]
> >>>>> *Sent:* Friday, March 27, 2015 6:00
> >>>>> *To:* Haoweiguo; Patrice Brissette (pbrisset)
> >>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]>
> >>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on
> >>>>> Paxos algorithm
> >>>>>
> >>>>> To recap,
> >>>>>
> >>>>> We have established that your proposal is untenable because of its
> >>>>> control plane load.
> >>>>>
> >>>>> We have established that your proposal is based upon a flawed
> >>>>> understanding of the DF election in RFC 7432.
> >>>>>
> >>>>> [weiguo]: In ethernet world, traffic loop is serious than short
> >>>>> timer traffic disruption. If you want to implement  transiet
> >>>>> traffic loop process, i will modify my draft to solve your issue.
> >>>>>
> >>>>> If i am the developer, i will prefer short timer traffic
> >>>>> disruption based on current EVPN protocol.
> >>>>>
> >>>>> What you are now arguing is that your draft prevents two or more
> >>>>> PEs from being DF simultaneously. This is clearly nonsense.
> >>>>>
> >>>>> [weiguo]: I will modify the draft problem statements, and use the
> >>>>>same  handshaking solution to solve it.
> >>>>>
> >>>>> Furthermore, we have established that having two or more DFs for
> >>>>> what even you admit is a brief transient leads to duplicate
> >>>>> traffic, which is acceptable, but not loops, your assertion to the
> contrary.
> >>>>>
> >>>>> [weiguo]: It is transient loop and traffic duplication issue.
> >>>>>
> >>>>> Yours Irrespectively,
> >>>>>
> >>>>> John
> >>>>>
> >>>>> *From:*Haoweiguo [mailto:[email protected]]
> >>>>> *Sent:* Thursday, March 26, 2015 5:37 PM
> >>>>> *To:* John E Drake; Patrice Brissette (pbrisset)
> >>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]>
> >>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on
> >>>>> Paxos algorithm
> >>>>>
> >>>>> John,
> >>>>>
> >>>>> As your understanding of the EVPN draft, the DF election mechanism
> >>>>>has  more serious side effect, it will have short time traffic
> >>>>>loop,i.e.,  dual DF PEs will exist for a short time. I think dual
> >>>>>DF PEs is  absolutely not tolerated, because native ethernet header
> >>>>>has no TTL,  up to several hundred ms traffic loop normally not
> >>>>>tolerated in  commertial networks.
> >>>>>
> >>>>> As your understanding, the PEs should do as following:
> >>>>>
> >>>>> 1. Accurate timer sync. NTP accuracy is bad, 1588v2 is good but
> >>>>> have rarely deployment.
> >>>>>
> >>>>> Assuming PE1,PE2 and PE3 have consistent timer clock, when PE3
> >>>>> joins ESI and trigger DF re-election. When reception timer expires:
> >>>>>
> >>>>> PE1 upgrades to DF PE.
> >>>>>
> >>>>> After reception timer+ ES route transmission timer:
> >>>>>
> >>>>> PE2 downloads to non-DF PE.
> >>>>>
> >>>>> So in timer clock sync case, dual DF PEs will exist at least
> >>>>> transmission timer.
> >>>>>
> >>>>> If NTP is used for timer sync, because it has bad accuracy, dual
> >>>>> DF PEs will exist more longer timer.
> >>>>>
> >>>>> So as your understanding for DF election, the drawback is more clear.
> >>>>>
> >>>>> Thanks,
> >>>>>
> >>>>> weiguo
> >>>>>
> >>>>>
> >>>>>-------------------------------------------------------------------
> >>>>>---
> >>>>>-
> >>>>>-
> >>>>>
> >>>>> *From:*John E Drake [[email protected]]
> >>>>> *Sent:* Friday, March 27, 2015 4:41
> >>>>> *To:* Haoweiguo; Patrice Brissette (pbrisset)
> >>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]>
> >>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on
> >>>>> Paxos algorithm
> >>>>>
> >>>>> Weiguo,
> >>>>>
> >>>>> We have already established that your proposal is untenable
> >>>>>because of  its control plane load.
> >>>>>
> >>>>> What we are now discussing is that your proposal is based upon a
> >>>>>misunderstanding of the algorithm in RFC 7432.  You are assuming
> >>>>>that
> >>>>> PE1 will advertise an ES route and then wait for the configured
> >>>>>interval before performing the DF election while PE2 and PE3 will
> >>>>>perform the DF election as soon as they receive the ES route from
> >>>>>PE1.
> >>>>> This is not what RFC 7432 says.
> >>>>>
> >>>>> Rather, what is says is that the advertisement of the ES route by
> >>>>> PE1 and its receipt by PE2 and PE3 causes all three PEs to start
> >>>>> the configured interval timer  - ³3. When the timer expires, each
> >>>>> PE builds an ordered list of the IP addresses of all the PE nodes
> >>>>> connected to the Ethernet segment (including itself), in
> >>>>> increasing numeric value.²
> >>>>>
> >>>>> Yours Irrespectively,
> >>>>>
> >>>>> John
> >>>>>
> >>>>> *From:*Haoweiguo [mailto:[email protected]]
> >>>>> *Sent:* Thursday, March 26, 2015 3:26 PM
> >>>>> *To:* John E Drake; Patrice Brissette (pbrisset)
> >>>>> *Cc:* Ali Sajassi (sajassi); [email protected] <mailto:[email protected]>
> >>>>> *Subject:* RE: [bess] Handshaking among PEs in an EVPN ES based on
> >>>>> Paxos algorithm
> >>>>>
> >>>>> Pls read my detail replies to Satya. If you still can't catch it,
> >>>>> pls read my draft and EVPN base protocol,  thanks
> >>>>>
> >>>>> weiguo
> >>>>>
> >>>>>
> >>>>>-------------------------------------------------------------------
> >>>>>---
> >>>>>-
> >>>>>-
> >>>>>
> >>>>> *From:*John E Drake [[email protected]]
> >>>>> *Sent:* Friday, March 27, 2015 1:28
> >>>>> *To:* Patrice Brissette (pbrisset)
> >>>>> *Cc:* Haoweiguo; Ali Sajassi (sajassi); [email protected]
> >>>>> <mailto:[email protected]>
> >>>>> *Subject:* Re: [bess] Handshaking among PEs in an EVPN ES based on
> >>>>> Paxos algorithm
> >>>>>
> >>>>> I think Patrice is correct.  Your proposal doesn't solve the
> >>>>> problem and it does so at huge cost.
> >>>>>
> >>>>> Sent from my iPhone
> >>>>>
> >>>>>
> >>>>> On Mar 26, 2015, at 10:34 AM, Patrice Brissette (pbrisset)
> >>>>> <[email protected] <mailto:[email protected]>> wrote:
> >>>>>
> >>>>>      Weiguo,
> >>>>>
> >>>>>      I¹m not sure I¹m following here.
> >>>>>
> >>>>>      Don¹t you have the same issue with your handshaking mechanism?
> >>>>>
> >>>>>      If you don¹t know your peer, how can you handshake?
> >>>>>
> >>>>>      Regards,
> >>>>>
> >>>>>      Patrice
> >>>>>
> >>>>>      Image removed by sender.
> >>>>>
> >>>>>      *Patrice Brissette*
> >>>>>      TECHNICAL LEADER.ENGINEERING
> >>>>>
> >>>>>      [email protected] <mailto:[email protected]>
> >>>>>      Phone: *+1 613 254 3336*
> >>>>>
> >>>>>
> >>>>>
> >>>>>      *Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE*
> >>>>>      Canada
> >>>>>      Cisco.com <http://www.cisco.com/global/CA/>
> >>>>>
> >>>>>
> >>>>>
> >>>>>      Image removed by sender.Think before you print.
> >>>>>
> >>>>>      This email may contain confidential and privileged material for
> >>>>>      the sole use of the intended recipient. Any review, use,
> >>>>>      distribution or disclosure by others is strictly prohibited. If
> >>>>>      you are not the intended recipient (or authorized to receive for
> >>>>>      the recipient), please contact the sender by reply email and
> >>>>>      delete all copies of this message.
> >>>>>
> >>>>>      Please click here
> >>>>>
> >>>>><http://www.cisco.com/web/about/doing_business/legal/cri/index.h
> tml>
> >>>>>      for Company Registration Information.
> >>>>>
> >>>>>
> >>>>>      *From: *Haoweiguo <[email protected]
> >>>>><mailto:[email protected]>>
> >>>>>      *Date: *Thursday, March 26, 2015 at 10:24 AM
> >>>>>      *To: *Patrice Brissette <[email protected]
> >>>>>      <mailto:[email protected]>>, John E Drake <[email protected]
> >>>>>      <mailto:[email protected]>>, Ali Sajassi <[email protected]
> >>>>>      <mailto:[email protected]>>, "[email protected]
> >>>>>      <mailto:[email protected]>" <[email protected] <mailto:[email protected]>>
> >>>>>      *Subject: *RE: [bess] Handshaking among PEs in an EVPN ES
> >>>>>based on
> >>>>>      Paxos algorithm
> >>>>>
> >>>>>          Hi Patrice,
> >>>>>
> >>>>>          Up to reception timer traffic disruption in transient
> >>>>>phase is
> >>>>>          one of the issues.
> >>>>>
> >>>>>          Thanks,
> >>>>>
> >>>>>          weiguo
> >>>>>
> >>>>>
> >>>>>-------------------------------------------------------------------
> >>>>>---
> >>>>>-
> >>>>>-
> >>>>>
> >>>>>          *From:*Patrice Brissette (pbrisset) [[email protected]
> >>>>>          <mailto:[email protected]>]
> >>>>>          *Sent:* Thursday, March 26, 2015 20:54
> >>>>>          *To:* Haoweiguo; John E Drake; Ali Sajassi (sajassi);
> >>>>>          [email protected] <mailto:[email protected]>
> >>>>>          *Subject:* Re: [bess] Handshaking among PEs in an EVPN ES
> >>>>>          based on Paxos algorithm
> >>>>>
> >>>>>          Weiguo,
> >>>>>
> >>>>>          You mention "But if your draft have not solved all
> >>>>> issues²,
> >>>>>
> >>>>>          Can you explain what Satya¹s draft is not solving?
> >>>>>
> >>>>>          Regards,
> >>>>>
> >>>>>          Patrice
> >>>>>
> >>>>>          Image removed by sender.
> >>>>>
> >>>>>          *Patrice Brissette*
> >>>>>          TECHNICAL LEADER.ENGINEERING
> >>>>>
> >>>>>          [email protected] <mailto:[email protected]>
> >>>>>          Phone: *+1 613 254 3336*
> >>>>>
> >>>>>
> >>>>>
> >>>>>          *Cisco Systems Canada Co. / Les Systemes Cisco Canada CIE*
> >>>>>          Canada
> >>>>>          Cisco.com <http://www.cisco.com/global/CA/>
> >>>>>
> >>>>>
> >>>>>
> >>>>>          Image removed by sender.Think before you print.
> >>>>>
> >>>>>          This email may contain confidential and privileged material
> >>>>>          for the sole use of the intended recipient. Any review, use,
> >>>>>          distribution or disclosure by others is strictly prohibited.
> >>>>>          If you are not the intended recipient (or authorized to
> >>>>>          receive for the recipient), please contact the sender by
> >>>>>reply
> >>>>>          email and delete all copies of this message.
> >>>>>
> >>>>>          Please click here
> >>>>>
> >>>>><http://www.cisco.com/web/about/doing_business/legal/cri/index.h
> tml>
> >>>>>          for Company Registration Information.
> >>>>>
> >>>>>
> >>>>>          *From: *Haoweiguo <[email protected]
> >>>>>          <mailto:[email protected]>>
> >>>>>          *Date: *Wednesday, March 25, 2015 at 10:38 PM
> >>>>>          *To: *John E Drake <[email protected]
> >>>>>          <mailto:[email protected]>>, Ali Sajassi <[email protected]
> >>>>>          <mailto:[email protected]>>, "[email protected]
> >>>>>          <mailto:[email protected]>" <[email protected]
> >>>>><mailto:[email protected]>>
> >>>>>          *Subject: *Re: [bess] Handshaking among PEs in an EVPN ES
> >>>>>          based on Paxos algorithm
> >>>>>
> >>>>>              Hi John,
> >>>>>
> >>>>>               Firstly i think EVPN community should reach
> >>>>>consensus on
> >>>>>              the issues of current DF election mechanism. All these
> >>>>>              issues should be resolved in a single new DF election
> >>>>>              draft,rather than in multiple separate drafts. If your
> >>>>>              draft can solve all these issues and stable, i have no
> >>>>>              question for its progressing. But if your draft have not
> >>>>>              solved all issues, i think it had better combine with
> >>>>>              other drafts to provide a comprehensive solution. I
> >>>>>think
> >>>>>              the issues listed in draft-rabadan-bess-evpn-ac-df-01
> >>>>>and
> >>>>>              draft-hao-bess-evpn-df-handshaking-00 is valid, it
> >>>>>should
> >>>>>              be resolved. So i think although your new Hash algorithm
> >>>>>              for DF election is good, it only includes partial
> >>>>>              enhancements, maybe it still needs some time for
> >>>>>consensus.
> >>>>>
> >>>>>              Thanks,
> >>>>>
> >>>>>              weiguo
> >>>>>
> >>>>>
> >>>>>-------------------------------------------------------------------
> >>>>>---
> >>>>>-
> >>>>>-
> >>>>>
> >>>>>              *From:*John E Drake [[email protected]
> >>>>>              <mailto:[email protected]>]
> >>>>>              *Sent:* Thursday, March 26, 2015 7:16
> >>>>>              *To:* Haoweiguo; Ali Sajassi (sajassi); [email protected]
> >>>>>              <mailto:[email protected]>
> >>>>>              *Subject:* RE: [bess] Handshaking among PEs in an
> >>>>>EVPN ES
> >>>>>              based on Paxos algorithm
> >>>>>
> >>>>>              Weiguo,
> >>>>>
> >>>>>              Your proposal introduces a control plane processing load
> >>>>>              that is O(#EVIs * PEs) per DF election and given that
> >>>>>              there can be 4K EVIs per ES, this looks like a
> >>>>>              **substantial** load. Furthermore,
> >>>>>
> >>>>>              you can¹t  use the ES route to co-ordinate DF election
> >>>>>              because you would need to carry your new extended
> >>>>>              community for each EVI and they would not all fit.  You
> >>>>>              also can¹t use the Per EVI Ethernet AD route because
> >>>>>that
> >>>>>              is processed by all PEs in the EVI.
> >>>>>
> >>>>>              I think that from a practical perspective the new DF
> >>>>>              election proposed in Satya¹s draft is sufficiently
> >>>>>stable
> >>>>>              that it renders your draft moot, even if it could be
> >>>>>made
> >>>>>              to work.
> >>>>>
> >>>>>              Yours Irrespectively,
> >>>>>
> >>>>>              John
> >>>>>
> >>>>>              *From:*BESS [mailto:[email protected]] *On Behalf Of
> >>>>>              *Haoweiguo
> >>>>>              *Sent:* Wednesday, March 25, 2015 5:34 PM
> >>>>>              *To:* Ali Sajassi (sajassi); [email protected]
> >>>>>              <mailto:[email protected]>
> >>>>>              *Subject:* Re: [bess] Handshaking among PEs in an
> >>>>>EVPN ES
> >>>>>              based on Paxos algorithm
> >>>>>
> >>>>>              Hi Ali,
> >>>>>
> >>>>>              Thanks for your information. I scanned through this
> >>>>>draft,
> >>>>>              it really introduces inter-chassis message for DF
> >>>>>election
> >>>>>              handshaking, the requirements in this draft is to
> >>>>>              eliminate transiet Loop and traffic duplication. Current
> >>>>>              EVPN DF election mechanism already eliminated loop and
> >>>>>              traffic duplication by configuring long reception
> >>>>>timer on
> >>>>>              each multi-homed PE, but up to reception timer traffic
> >>>>>              disruption issue still exist. EVPN for DCI is an
> >>>>>important
> >>>>>              use case for EVPN, up to reception timer traffic
> >>>>>              disruption can't be tolerated for service providers, it
> >>>>>              should be improved.
> >>>>>
> >>>>>              Also for accuracy, i think handshaking state machine on
> >>>>>              each multi-homed PE is also needed. From solution
> >>>>>              perspective, in my draft, no inter-chassis message is
> >>>>>              introduced, only one new extended community is
> >>>>>introduced,
> >>>>>              i think the process is comparatively simple than your
> >>>>>              following draft.
> >>>>>
> >>>>>              Current EVPN DF election has some drawbacks, so there
> >>>>>are
> >>>>>              three new drafts about DF election emerged. I think BESS
> >>>>>              WG can consider these three drafts in global view, a
> >>>>>              single,comprehensive new DF election draft is hoped.
> >>>>>
> >>>>>              thanks.
> >>>>>
> >>>>>              Thanks,
> >>>>>
> >>>>>              weiguo
> >>>>>
> >>>>>
> >>>>>-------------------------------------------------------------------
> >>>>>---
> >>>>>-
> >>>>>-
> >>>>>
> >>>>>              *From:*BESS [[email protected]
> >>>>>              <mailto:[email protected]>] on behalf of Ali Sajassi
> >>>>>              (sajassi) [[email protected] <mailto:[email protected]>]
> >>>>>              *Sent:* Thursday, March 26, 2015 0:21
> >>>>>              *To:* [email protected] <mailto:[email protected]>
> >>>>>              *Subject:* [bess] Handshaking among PEs in an EVPN ES
> >>>>>              based on Paxos algorithm
> >>>>>
> >>>>>              FYI- First published July 4, 2011
> >>>>>
> >>>>>
> >>>>>https://datatracker.ietf.org/doc/draft-sajassi-l2vpn-evpn-segment-r
> >>>>>out
> >>>>>e
> >>>>>/
> >>>>>
> >>>>>              -Ali
> >>>>>
> >>>>>
> >>>>>
> >>>>> _______________________________________________
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> >>>>
> >>>>
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> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
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