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Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
Agreed
-----Original Message-----
From: Stewart Bryant [mailto:stbryant at cisco.com]
Sent: donderdag 19 november 2009 14:24
To: HENDERICKX Wim
Cc: Andrew G. Malis; pwe3 at ietf.org; Luca Martini
Subject: Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
See my earlier mail, I think that the mode of operation you wanted can
be made to work with the existing approach.
- Stewart
HENDERICKX Wim wrote:
> Andy,
>
> I am happy to write a new draft, but I was suggesting to update
Stewarts draft with this information. Either way is fine by me.
>
> The way I want to signal this capability is using similar procedure as
what Stewart suggested.
>
> Cheers,
> Wim
>
> -----Original Message-----
> From: Andrew G. Malis [mailto:amalis at gmail.com]
> Sent: donderdag 19 november 2009 12:27
> To: HENDERICKX Wim
> Cc: Luca Martini; pwe3 at ietf.org; stbryant at cisco.com
> Subject: Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
>
> Wim,
>
> What procedures would you use to allocate and signal that combined
> label? If we were to use such a label, it would have to be practical
> to do so, and we would need a procedure and text for the draft.
>
> Thanks,
> Andy
>
> On Thu, Nov 19, 2009 at 3:22 AM, HENDERICKX Wim
> <wim.henderickx at alcatel-lucent.be> wrote:
>
>> Luca, for IP you are right in terms of protocol stack but I have the
>> impression that the packet-PW draft is more generic and we should be
>> open minded to other applications apart from IP.
>>
>> What I propose is to have 1. tunnel label - 2. pw label - 3. a label
>> which combines the pid label + CW + hash label.
>>
>> -----Original Message-----
>> From: Luca Martini [mailto:lmartini at cisco.com]
>> Sent: woensdag 18 november 2009 23:18
>> To: HENDERICKX Wim
>> Cc: stbryant at cisco.com; pwe3 at ietf.org
>> Subject: Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
>>
>> Wim,
>>
>> We can , of course , always reduce the label stack depth by merging
>> labels, but that is usually not a good idea , as it will increase the
>> number of labels, that that is the most expensive part of MPLS.
>> Also note that The FAT PW would not be very useful with a packet PW
that
>>
>> contains IP.
>> Let assume for a moment that 99.9% of traffic in a packet PW will be
IP
>> ... ( most likely it's much higher then that )
>> I do not like the CW much , so let say that we simply encapsulate the
IP
>>
>> packet into a protocol label, a PW label, and a tunnel label.
>> That's a 3 label stack , with excellent load sharing capabilities. If
>> you pull the PID out into a CW , for example , you will have to add
>> another label , and also make the encapsulation process much more
>> complicated at the PE.
>> So , for this application it's better to just have 3 labels.
>>
>> Luca
>>
>>
>>
>>
>> HENDERICKX Wim wrote:
>>
>>> I would vote for the latter. It is not much about the label
uniqueness
>>> but the depth of the stack since it reduces BW.
>>>
>>> If we embed the e-type in the label it becomes more easy as well.
>>>
>>> -----Original Message-----
>>> From: Stewart Bryant [mailto:stbryant at cisco.com]
>>> Sent: maandag 16 november 2009 18:15
>>> To: HENDERICKX Wim
>>> Cc: Andrew G. Malis; pwe3 at ietf.org
>>> Subject: Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
>>>
>>> It depends what you mean by optimize.
>>>
>>> Say you have 100 PWs and 2 protocols
>>>
>>> If you optimize for minimum number of unique labels by separating
the
>>> functions, as per the draft, this takes 102 labels
>>>
>>> If you optimize for number of labels in the stack, which is what you
>>>
>> are
>>
>>> requesting, you need 200 unique labels.
>>>
>>> - Stewart
>>>
>>>
>>>
>>>
>>> HENDERICKX Wim wrote:
>>>
>>>
>>>> This is correct but could we not optimize this special mapping ?
>>>>
>>>> -----Original Message-----
>>>> From: Andrew G. Malis [mailto:amalis at gmail.com]
>>>> Sent: maandag 16 november 2009 15:39
>>>> To: HENDERICKX Wim
>>>> Cc: stbryant at cisco.com; pwe3 at ietf.org
>>>> Subject: Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
>>>>
>>>> Wim,
>>>>
>>>> It's still more efficient on the wire than a simulated Ethernet PW,
>>>> because you would have one less label (the protocol identifier),
but
>>>> would add the Ethernet MAC header instead.
>>>>
>>>> Cheers,
>>>> Andy
>>>>
>>>> On Mon, Nov 16, 2009 at 9:03 AM, HENDERICKX Wim
>>>> <wim.henderickx at alcatel-lucent.be> wrote:
>>>>
>>>>
>>>>
>>>>> Ok good, this is what I thought, the client LSP exist in the
"client
>>>>> packet Network layer".
>>>>>
>>>>> Don't you think this is a huge stack for such a function. You
could
>>>>>
>>>>>
>>> have
>>>
>>>
>>>>> 4-6 LBL(s) + CW (optionally). I understand this proposal re-uses
>>>>> existing functions defined in MPLS, but there are lot's of
>>>>>
>>>>>
>>> optimizations
>>>
>>>
>>>>> possible here -> we could combine FAT LBL, PID LBL, CW
potentially.
>>>>>
>>>>> -----Original Message-----
>>>>> From: Stewart Bryant [mailto:stbryant at cisco.com]
>>>>> Sent: maandag 16 november 2009 14:49
>>>>> To: HENDERICKX Wim
>>>>> Cc: pwe3 at ietf.org
>>>>> Subject: Re: [PWE3] draft-bryant-pwe3-packet-pw-02.txt
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>> WH> what I meant is this:
>>>>>>>
>>>>>>> -------- --------
>>>>>>> PE1-----| | | | --- PE3
>>>>>>> | LSR |------- PKT PW ------| LSR |
>>>>>>> | | | |
>>>>>>> PE2-----| | | |---- PE4
>>>>>>> -------- --------
>>>>>>>
>>>>>>> Assume PE1 has a LSP to PE3 and PE2 has an LSP to PE4, how is
this
>>>>>>> distinguished on the PKT PW ?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>> SB> I am not sure what you have drawn there, but it is not what
is
>>>>>>
>>>>>>
>>>>>>
>>>>> shown
>>>>>
>>>>>
>>>>>
>>>>>> in the draft. The pkt pw run between the PEs and is carried over
>>>>>>
>>>>>>
>>> the
>>>
>>>
>>>>>> LSPs. PWs are distinguished from each other at the PE via the PW
>>>>>>
>>>>>>
>>>>>>
>>>>> label.
>>>>>
>>>>>
>>>>>
>>>>>> WH> What I tried to draw is PE(s) attached to the device (drawn
>>>>>>
>> with
>>
>>>>>>
>>>>> the
>>>>>
>>>>>
>>>>>
>>>>>> box) which is performing the LSR function on a PKT PW to another
>>>>>>
>>>>>>
>>>>>>
>>>>> device
>>>>>
>>>>>
>>>>>
>>>>>> (drawn with the box) which attaching PE(s).
>>>>>>
>>>>>> The question is if I have multiple LSPs from different PE(s)
>>>>>>
>> through
>>
>>>>>>
>>>>> the
>>>>>
>>>>>
>>>>>
>>>>>> PKT PW how are the distinguished. Do I need a separate PID LBL, a
>>>>>> separate PW, etc such that the LSR can make the correct LBL
>>>>>>
>>>>>>
>>> mappings.
>>>
>>>
>>>>>>
>>>>> Wim
>>>>>
>>>>> Think of the PW as a point to point link between a pair of PEs.
The
>>>>>
>>>>>
>>> PE
>>>
>>>
>>>>> chooses what traffic to sent over a given PW. The PE then pushes
an
>>>>>
>>>>>
>>> MPLS
>>>
>>>
>>>>> label to identify the destination. The mid-point LSRs have no clue
>>>>>
>>>>>
>>> what
>>>
>>>
>>>>> is being carried over the LSP. The egress PE unwraps that packet
and
>>>>> figures out what the payload is.
>>>>>
>>>>> RFC3985 applies to pkt pw as it does to any other PW.
>>>>>
>>>>> - Stewart
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> pwe3 mailing list
>>>>> pwe3 at ietf.org
>>>>> https://www.ietf.org/mailman/listinfo/pwe3
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>> _______________________________________________
>>> pwe3 mailing list
>>> pwe3 at ietf.org
>>> https://www.ietf.org/mailman/listinfo/pwe3
>>>
>>>
>> _______________________________________________
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>>
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