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ietf-ccamp-wg / ietf-ccamp-layer0-types-ext-RFC9093-bis

CCAMP WG repository for ietf-layer0-types-ext
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Boundary between Layer 0 and Layer 1 #81

Open sergiobelotti opened 1 year ago

sergiobelotti commented 1 year ago

https://github.com/ietf-ccamp-wg/draft-ietf-ccamp-flexigrid-yang/issues/58

sergiobelotti commented 1 year ago

This issue will be discussed in the context of flexible grid meeting. We will take it open till there are no feedback form the discussion in the flexible grid context.

ggrammel commented 10 months ago

https://datatracker.ietf.org/doc/rfc1208/ is using the OSI Model as layering criteria but doesn't attach a number to any layer except for layer-0:

Physical Layer: The OSI layer that provides the means to activate and use physical connections for bit transmission. In plain terms, the Physical Layer provides the procedures for transferring a single bit across a Physical Media.

Physical Media: Any means in the physical world for transferring signals between OSI systems. Considered to be outside the OSI Model, and therefore sometimes referred to as "Layer 0." The physical connector to the media can be considered as defining the bottom interface of the Physical Layer, i.e., the bottom of the OSI.

image (Source: https://en.wikipedia.org/wiki/OSI_model) is in line with above and defines bits and symbols as pertaining to Layer-1.

With that definition the split between Layer-0 and Layer-1 would be the bit or symbol pertaining to Layer-1. This would put the following parameters into Layers: Layer1: FEC, Framing, bitrate, symbol rate .... Layer0: total RX-power, Signal TX/RX-power, SNR, impairment compensation, frequency, ....

sergiobelotti commented 9 months ago

https://github.com/ietf-ccamp-wg/ietf-ccamp-layer0-types-ext-RFC9093-bis/issues/2#issuecomment-635370654 See the link of slides

ggrammel commented 8 months ago

https://github.com/ietf-ccamp-wg/draft-ietf-ccamp-flexigrid-yang/issues/58#issuecomment-1429786774 is a set of valuable slides that puts the L0 boundary at the OTSi termination. https://www.ietf.org/lib/dt/documents/LIAISON/liaison-2019-07-18-itu-t-sg-15-ccamp-ls-on-description-of-otsi-and-network-media-channel-attachment-1.pdf which clarifies "The OTSi, defined in [ITU-T G.959.1], is the signal that is carried between the output of an OTSi modulator and the input of an OTSi demodulator." This all seems to be consistent with https://datatracker.ietf.org/doc/rfc1208/ associating Layer-1 to a bit-stream, which is the input of a modulator and the output of a de-modulator.

manzoro commented 3 months ago

Update the slide present in https://github.com/ietf-ccamp-wg/draft-ietf-ccamp-flexigrid-yang/issues/58 with info on OpenZR+ multiplexing and pointer to OpenZR+ MSA

layer0-boundary-02.pptx

manzoro commented 2 months ago

As per the discussion during the call on June 18, there is a good consensus on the fact that this issue may need a better description and refocus on its original purpose. Leaving out the possible identification of a management boundary between L0 and L1, the main purpose of this issue is to identify if we need additional type definition to allow a proper identification of the termination point capability/interoperability in the flex/fixed DWDM tunnel model.

While the L0 application-code provide a clear identification of the photonics signal up to the modulation and FEC format, and the L1 ODU multiplexing schema clearly define the OTN payload structure where present, there is a set of adaptation layer and possible inverse multiplexing configuration in the middle that are not described in any model.

So the focus and purpose of this issue is to define any typedef/attribute that may be useful to fill this gap and describe the end point data structure and adaptation that may be present between L1 multiplexing and L0 application-code definition

Reattaching the slide set with updated scenario for ZR and ZR+

layer0-boundary-03.pptx