Re: [mpls] [PWE3] 1588 over MPLS draft

Hi Shahram,

I agree that the label range idea is an efficient way that could reduce the 
storage requirement of PHY chips.

It's easy to require one or limited nodes to reserve a label range, but 
IMHO, it very difficut to require all nodes of a large network to do this 
and even worse when some labels are already used by other LSPs, unless there 
are some mechanisms to negotiate/advertise(e.g., flooding the label range by 
IGP within the network) the proper label range hence to aviod label 
collision.

Best regards,
Mach

--------------------------------------------------
From: "Shahram Davari" <davari@broadcom.com>
Sent: Thursday, July 15, 2010 1:58 AM
To: "Mach Chen" <mach@huawei.com>; "S. Davari" <davarish@yahoo.com>; "Jia 
HE" <hejia@huawei.com>
Cc: <mpls@ietf.org>; <pwe3@ietf.org>; <ticctoc@ietf.org>; <mpls-tp@ietf.org>
Subject: RE: [mpls] [PWE3] 1588 over MPLS draft

> Hi Mach,
>
> When a service provider wants to create these PTP LSPs, what is wrong with 
> allocating a range of labels for this purpose? This is purely a software 
> exercise. There are 2 million labels available to each node, why can't 
> some of them be allocated by software to PTP?
>
> In theory what you say is correct and should work, but in practice there 
> is a function called 1-step Transparent clocking that requires time 
> stamping at the PHY (immediately when the packet is received or 
> transmitted). PHY chips don't have CAM or lots of memory to store a few 
> thousand random labels. The label range will solve that problem and is 
> consistent with MPLS architecture.
>
> Thanks,
> Shahram
>
> -----Original Message-----
> From: Mach Chen [mailto:mach@huawei.com]
> Sent: Wednesday, July 14, 2010 1:53 AM
> To: S. Davari; Jia HE; Shahram Davari
> Cc: mpls@ietf.org; pwe3@ietf.org; ticctoc@ietf.org; mpls-tp@ietf.org
> Subject: Re: [mpls] [PWE3] 1588 over MPLS draft
>
> Hi Shahram,
>
> From the view of implementation, there is no more difference between 
> SHOULD
> and MUST :-)
> For me, the Label Range is more like a mechanim to notify related nodes 
> that
> some LSPs are dedicated for PTP messages other than the chips memory
> limitation, because the memory restriction is always there whatever you 
> use
> Label Range or not.
> IMHO, since the objective is to tell related MPLS nodes which LSPs are PTP
> LSPs, an indication in the signaling(RSVP-TE/GMPLS/LDP) is enough and 
> seems
> more common. And it will avoid the strict requirement of "the network and
> all nodes required to support the Label range".
> In addition, there should be some mechanims(e.g., ISIS/OSPF extensions) 
> for
> nodes to advertise their PTP capability hence to help PTP LSPs 
> computation.
>
> Best regards,
> Mach
>
>
> --------------------------------------------------
> From: "S. Davari" <davarish@yahoo.com>
> Sent: Wednesday, July 14, 2010 2:31 PM
> To: "Jia HE" <hejia@huawei.com>; "Shahram Davari" <davari@broadcom.com>
> Cc: <mpls@ietf.org>; <pwe3@ietf.org>; <ticctoc@ietf.org>; 
> <mpls-tp@ietf.org>
> Subject: Re: [mpls] [PWE3] 1588 over MPLS draft
>
>> Hi Jia,
>>
>> Label range is a SHOULD requirements and not MUST. The reason for Label
>> Range is
>> mainly for PHY chips that don't have large memory and can't store a lot 
>> of
>> Labels. Otherwise the PTP LSP is setup via signaling that specifies the
>> LSP as
>> carrying 1588.
>>
>> So the answer is that if a Label range is used it must be a Global range
>> within
>> a network and should not be used by any router for other applications.
>>
>> Thanks,
>> Shahram
>>
>>
>>
>> ________________________________
>> From: Jia HE <hejia@huawei.com>
>> To: Shahram Davari <davari@broadcom.com>
>> Cc: mpls@ietf.org; pwe3@ietf.org; ticctoc@ietf.org; mpls-tp@ietf.org
>> Sent: Tue, July 13, 2010 9:50:37 PM
>> Subject: Re: [mpls] [PWE3] 1588 over MPLS draft
>>
>>
>> Hi Shahram,
>>
>> One question about "PTP Label Range":
>>
>> To my knowledge, label in MPLS network is a local  matter. For example, 
>> we
>> may
>> have per-interface or per-platform label space. Will  this specificed 
>> "PTP
>> Label
>> Range" conflict with the current in-use labels  for common LSPs?
>>
>>
>> B.R.
>> Jia
>>
>> ----- Original Message ----- 
>>>From: Shahram    Davari
>>>To: ticctoc@ietf.org ; mpls@ietf.org ; mpls-tp@ietf.org ; pwe3@ietf.org
>>>Sent: Thursday, July 08, 2010 3:12 AM
>>>Subject: [PWE3] 1588 over MPLS draft
>>>
>>>
>>>Hi All,
>>>
>>>Please find attached our first draft of 1588 over MPLS.    Since we have
>>>some
>>>technical issues converting the Word format to Txt we    couldn’t 
>>>upload
>>>the
>>>draft before the cut-off date. However we will    present the draft in 
>>>the
>>>next
>>>IETF meeting and will upload the draft after the    meeting.
>>>
>>>Note that the main WG is TicToc but may require    consultation with MPLS
>>>and
>>>PWE3 WGs.
>>>
>>>Thanks,
>>>Shahram Davari
>> ________________________________
>> _______________________________________________
>>>pwe3 mailing    list
>>>pwe3@ietf.org
>>>https://www.ietf.org/mailman/listinfo/pwe3
>>>
>>
>>
>
>
>
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>
>
> 