[i2rs] Mail regarding draft-ietf-i2rs-yang-l2-network-topology

[Stephen Cheng <[e-mail]>]

Dear authors,

I have a number of questions regarding this L2 topology YANG.


  1.  Does draft-ietf-i2rs-yang-l2-network-topology support the modelling of a termination point that maps to a VLAN sub-interface?
This capability would facilitate the creation of a topology stack for the following use cases:

     *   Mapping a ietf-l3-topology TP over a vlan sub-interface
In this case a TP in ietf-l3-topology instance would be supported by a VLAN sub-interface TP in the l2-topology
     *   Mapping different VLAN IDs in a L2 ports to different services

                                                               i.      For example, on a particular L2 port, VLAN 23 might be an attachment circuit for VPLS #78, where as VLAN 99 might be an attachment circuit for L3VPN #999

If draft-ietf-i2rs-yang-l2-network-topology does not have the capability to model VLAN sub-interface as a TP, is there a different way for draft-ietf-i2rs-yang-l2-network-topology to support the above use cases?



  1.  The VLAN sub-interface YANG (https://tools.ietf.org/pdf/draft-ietf-netmod-sub-intf-vlan-model-06.pdf) being developed has some overlap with draft-ietf-i2rs-yang-l2-network-topology. It would be good if there would be better alignment between the two:
     *   Use similar definition/fields where possible; even better use shared grouping definition

                                                               i.      For example outer-tag and inner-tag

     *   VLAN sub-interface YANG (https://tools.ietf.org/pdf/draft-ietf-netmod-sub-intf-vlan-model-06.pdf) flexible encapsulation supports symmetric and asymmetric rewrites, which does not appear to be supported by draft-ietf-i2rs-yang-l2-network-topology.


  1.  Consider the scenario where a domain controller implementing draft-ietf-i2rs-yang-l2-network-topology is also implementing schema mounted ietf-interface to model the interface stacks of the managed devices:

  *   Is there a mechanism in draft-ietf-i2rs-yang-l2-network-topology to associate a L2 TP with the corresponding interface entry in the schema mounted ietf-interface?


  1.  For a LAG link, would the LAG TP be expected to be also represented by /nw:networks/nw:network/nw:node:termination-point/tp-id/supporting-termination-point to its membership TPs?
It would be useful to clarify for uniform implementation across different vendors.

Thank you.

Warm regards,
Stephen Cheng
Aviat Networks