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RE: Label type to be used
Dimitri,
I would like a clarification on the following three combinations of your
proposal:
> > [LSC, LSC] - label represents a G.709 OCh/lambda/port
> > [PSC, LSC] - label represents a G.709 OCh/lambda/port
> > [TDM, LSC] - label represents a G.709 OCh/lambda/port
What exactly you mean by OCh?
What exactly you mean by OCh/lambda/port?
Does it mean that the devices on both sides of such a TE-Link must be able
to generate and accept all these three types? If the answer is yes, then it
is not clear to me how a TDM/PSC capable device be able to do that. A TDM
device knows how to switch time slots and that's it. Does it make sense for
a TDM capable device that is also an LTE to advertise FSC capability for the
TE-Links?
Thanks,
Vijay
-----Original Message-----
From: Dimitri.Papadimitriou@alcatel.be
[mailto:Dimitri.Papadimitriou@alcatel.be]
Sent: Thursday, April 01, 2004 5:18 PM
To: Ong, Lyndon
Cc: 'Lou Berger'; Kireeti Kompella; ccamp@ops.ietf.org
Subject: Re: Label type to be used
hi lyndon,
Ong, Lyndon wrote:
> Hi Dimitri,
>
> I think it was my mistake, in testing I have seen people use
> FSC to describe an interface to an opaque OXC with SDH framing
> when they wish to have the entire signal (minus some SDH
> overhead) switched rather than sorting through individual
> channels. On further reading of draft-ietf-ccamp-gmpls-routing-09.txt
> it looks like section 3.5 specifically describes this as a
> case where LSC would be advertised rather than FSC, since
> there is conceptually a single wavelength, is this
> still correct?
yes, this is why i have proposed the below to adapt the below
in-line with the following paragraph of section 3.5
" An interface on an opaque OXC handles a single wavelength, and
cannot switch multiple wavelengths as a whole. Thus, an interface on
an opaque OXC is always LSC, and not FSC, irrespective of whether
there is DWDM external to it."
thanks,
- dimitri.
> Thanks,
>
> Lyndon
>
> -----Original Message-----
> From: Dimitri.Papadimitriou@alcatel.be
> [mailto:Dimitri.Papadimitriou@alcatel.be]
> Sent: Saturday, March 27, 2004 4:31 AM
> To: Ong, Lyndon
> Cc: 'Lou Berger'; Kireeti Kompella; ccamp@ops.ietf.org
> Subject: Re: Label type to be used
>
>
> the proposal that makes a fully transparent Sonet/SDH encoded capable
> link appearing as [X,LSC] or [LSC,X], or [LSC,LSC] w/ a label defined as
> a port and/or lambda is aligned with the evolution of the definition
> towards OTN (coming from the so-called pre-OTN) technology and thus
> probably better than trying to retain the TDM value for it (with several
> flavours)
>
> so you would have something like this when trying to harmonize in
> between the several documents we have tnat deals with this specific
> representation issue, i also think it provides the distinction you're
> asking for b/w fiber and so-called clear channels:
>
> 2.4.4. Lambda-Switch Capable
>
> If an interface is of type LSC, it means that the node receiving data
> over this interface can recognize and switch individual lambdas
> within the interface. An interface that allows only one lambda per
> interface, and switches just that lambda is of type LSC.
> > This includes interfaces that only support fully transparent SONET/SDH
> > signals, as defined in [GMPLS-SONET-SDH].
>
> [...]
>
> 2.4.7. Interface Switching Capabilities and Labels
>
> [PSC, PSC] - label is carried in the "shim" header [RFC3032]
> > [TDM, TDM] - label represents a timeslot ([GMPLS-SONET-SDH],
> [GMPLS-G709])
> > [LSC, LSC] - label represents a G.709 OCh/lambda/port
> > [FSC, FSC] - label represents a fiber (i.e. physical port)
> > [PSC, TDM] - label represents a timeslot ([GMPLS-SONET-SDH],
> [GMPLS-G709])
> > [PSC, LSC] - label represents a G.709 OCh/lambda/port
> > [PSC, FSC] - label represents a fiber
> > [TDM, LSC] - label represents a G.709 OCh/lambda/port
> > [TDM, FSC] - label represents a fiber
> > [LSC, FSC] - label represents a fiber
>
> > Note: except when explicitly indicated the label encoding MUST follow
> > the rules defined in [RFC3471] Section 3.2.
>
> ps: in fact one sees here that for the "timeslot" case, the switching
> type TDM value equates the encoding one
>
>
> Ong, Lyndon wrote:
>
>>Hi Lou,
>>
>>Your proposed text looks pretty good to me.
>>
>>Side note: is there a way that the
>>existing text can be clarified to distinguish
>>between the case of only one lambda allowed
>>on an interface and the case of fiber switching?
>>
>>Currently the text seems to allow an overlap
>>in the case of a non-channelized OC-12/48/etc. as in
>>a sense there is only one "lambda" but you would
>>typically request fiber switching.
>>
>>Cheers,
>>
>>Lyndon
>>
>>-----Original Message-----
>>From: Lou Berger [mailto:lberger@movaz.com]
>>Sent: Friday, March 26, 2004 11:17 AM
>>To: Kireeti Kompella
>>Cc: ccamp@ops.ietf.org; John Drake
>>Subject: RE: Label type to be used
>>
>>
>>Kireeti,
>> I think John's points on (a) and (c) are reasonable. I think the
>>only changes needed to the draft-ietf-ccamp-gmpls-routing-09.txt to make
>>this clear are:
>>
>> 2.4.4. Lambda-Switch Capable
>>
>> If an interface is of type LSC, it means that the node receiving data
>> over this interface can recognize and switch individual lambdas
>> within the interface. An interface that allows only one lambda per
>> interface, and switches just that lambda is of type LSC.
>> > This includes interfaces that only support fully transparent SONET/SDH
>> > signals, as defined in [GMPLS-SONET-SDH].
>>
>>and
>> [PSC, PSC] - label is carried in the "shim" header [RFC3032]
>> [TDM, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
>> > [LSC, LSC] - label represents a lambda/port
>> [FSC, FSC] - label represents a port on an OXC
>> [PSC, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
>> > [PSC, LSC] - label represents a lambda/port
>> [PSC, FSC] - label represents a port
>> > [TDM, LSC] - label represents a lambda/port
>> [TDM, FSC] - label represents a port
>> [LSC, FSC] - label represents a port
>>
>>Lou
>>
>>PS This matches all but one implementation we've interoperated with.
>>
>>At 01:49 PM 3/26/2004 -0500, John Drake wrote:
>>
>>
>>
>>
>>>>-----Original Message-----
>>>>From: Kireeti Kompella
>>>
>>>[<mailto:kireeti@juniper.net>mailto:kireeti@juniper.net]
>>>
>>>
>>>>Sent: Thursday, March 18, 2004 9:58 AM
>>>>To: ccamp@ops.ietf.org
>>>>Subject: Label type to be used
>>>>
>>>>Hi,
>>>>
>>>>Arthi and Lou pointed out the following typos in the GMPLS routing doc
>>>>(draft-ietf-ccamp-gmpls-routing-09.txt) which is now in the RFC
>>>>Editor's queue:
>>>>
>>>>In section 2.4.7 is the following table defining the type of label
>>>>for various combinations of switching types:
>>>>
>>>> [PSC, PSC] - label is carried in the "shim" header [RFC3032]
>>>> [TDM, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
>>>> [LSC, LSC] - label represents a lambda
>>>> [FSC, FSC] - label represents a port on an OXC
>>>> [PSC, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
>>>> [PSC, LSC] - label represents a lambda
>>>> [PSC, FSC] - label represents a port
>>>> [TDM, LSC] - label represents a lambda
>>>> [TDM, FSC] - label represents a port
>>>> [LSC, FSC] - label represents a port
>>>>
>>>>The one at issue is [PSC, LSC]; above it says that the label
>>>>represents a lambda; and in the case of [PSC, TDM] with a fully
>>>>transparent signal, the above indicates the label represents a TDM
>>>>time slot. The proposal is to change this to:
>>>>
>>>> [PSC, PSC] - label is carried in the "shim" header [RFC3032]
>>>> [TDM, TDM] - label represents a TDM time slot [GMPLS-SONET-SDH]
>>>> [LSC, LSC] - label represents a lambda
>>>> [FSC, FSC] - label represents a port on an OXC
>>>> [PSC, TDM] - fully transparent signal: label represents a port
>>>> ("transparency" is defined in [GMPLS-SONET-SDH])
>>>> [PSC, TDM] - non-transparent signal: label represents a TDM time
>>>> slot [GMPLS-SONET-SDH]
>>>> [PSC, LSC] - label represents a port
>>>> [PSC, FSC] - label represents a port
>>>> [TDM, LSC] - label represents a lambda
>>>> [TDM, FSC] - label represents a port
>>>> [LSC, FSC] - label represents a port
>>>>
>>>>Please respond by Friday 3/26, 5pm PST with comments on:
>>>>
>>>>a) do you agree with the above change?
>>>
>>>[John Drake]
>>>
>>>I don't have a problem with the [PSC, LSC] change but I don't
>>>understand the distinction between transparent and non-transparent
>>>TDM as it pertains to GMPLS routing. As I indicated in a previous
>>>e-mail, I think the transparent TDM case should be handled with a
>>>switching type of LSC and an encoding type of SDH/SONET, and I think
>>>that this should be specified in the SDH/SONET I-D, where the distinction
>>>between transparent and non-transparent TDM is defined, rather than in
>>>this document.
>>>
>>>
>>>
>>>>b) in your implementation today, what do expect the label to represent
>>>> i) in the case of [PSC, LSC]?
>>>
>>>[John Drake]
>>>
>>>Port/lambda
>>>
>>>
>>>
>>>> ii) in the case of [PSC, TDM] with a fully transparent signal?
>>>>c) if you implement as the draft says, would it be a hardship to change
>>>> this?
>>>
>>>[John Drake]
>>>
>>>N/A. Labels for SDH/SONET are defined in the SDH/SONET I-D and it's
pretty
>>>clear about which types of labels are in the transparent and
non-transparent
>>>TDM cases.
>>>
>>>
>>>
>>>>If we can get closure on this, I'll take up the task of modifying the
>>>>pending RFC with the ADs.
>>>>
>>>>Kireeti.
>>>>-------
>>
>>
>>
>
--
Papadimitriou Dimitri
E-mail : dimitri.papadimitriou@alcatel.be
E-mail : dpapadimitriou@psg.com
Webpage: http://psg.com/~dpapadimitriou/
Address: Fr. Wellesplein 1, B-2018 Antwerpen, Belgium
Phone : +32 3 240-8491