As a data point, RFC 7407 uses sub-modules. The sub-modules more or less reflect SNMPv3's modular architecture, the different transports are for example separated out as sub-modules. I guess we also used sub-modules back then because we wanted to see how this works in an IETF context (RFC 7407 was approved/published 6 years ago, we were still learning how to use YANG at that time).
I personally meanwhile believe that sub-modules add complexity with little extra value but this view surely is not shared by others. Anyway, people using them should have a good reason for using them. Since SNMPv3 has a great modular architecture, it makes sense to structure the YANG modules accordingly and instead of having many ietf-snmp-<foo> modules, sub-modules came in handy to have everything in a single namespace. For technologies that do not have a modular architecture that can be followed, creating modular sub-modules is likely not worth the effort. /js PS: I am not sure that sub-modules are necessarily harder to review. For the crypto YANG modules, we have several intertwined modules, they are likely as complex to review as if they were all sub-modules sharing a single namespace - or a single module with all definitions in one big module. On Wed, Aug 05, 2020 at 04:20:17PM +0000, tom petch wrote: > Looking at an I-D with endless submodules, I am left thinking > > Costs > > greater in size > more complex to understand > harder to review > more likely to have undetected errors > > Benefits > > > > What am I missing? I have only ever seen one such module in the IETF that I > can recall and it is draft-ietf-idr-bgp-model and AFAICT it would be smaller, > simpler, easier to understand if it were done with grouping instead of > submodule. > > Tom Petch > > _______________________________________________ > netmod mailing list > netmod@ietf.org > https://www.ietf.org/mailman/listinfo/netmod -- Juergen Schoenwaelder Jacobs University Bremen gGmbH Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany Fax: +49 421 200 3103 <https://www.jacobs-university.de/> _______________________________________________ netmod mailing list netmod@ietf.org https://www.ietf.org/mailman/listinfo/netmod