I have been asked to review this draft and the L1CSM YANG module it includes on behalf of YANG Doctors.  Overall, I think the draft/module is ready, but I did find a few small issues.  First, please run "pyang -f yang" on this to normalize its formatting.  There were a few spacing and other formatting issues that will be cleaned up by doing this.  Other items are below:

In the header of the YANG module, you import ietf-layer1-types with a mark of RFCYYYY.  In your comment below calling out RFCXXXX (i.e., this RFC) it would be good to point the RFC Editor to YYYY as well.

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In your identity definition section, you have a number of identity descriptions which are self-referential.  Admittedly, this is one of my pet peeves, but if you could add more clarifying description text to identities such as one-way-delay, one-way-errored-second, etc. it would help implementors and operators better consume the YANG module without always needing to refer to external references.

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Can time-interval be uint32 instead of int?  I do not thing a negative time interval is possible/useful here.

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The description of the grouping subscriber-l1vc-sls-service-attributes doesn't look accurate.  This is not a value per se, but a collection of attributes.

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In the /services/service list you explicitly have "mandatory true" for the key service-id.  This is not needed since the key is mandatory.