Re: [netconf] RFC8639 capability on https-notif receiver implementation

Kent Watsen <> Thu, 27 May 2021 15:07 UTC

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From: Kent Watsen <>
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Date: Thu, 27 May 2021 15:07:46 +0000
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Cc:, pierre francois <>, Axel Rosenstiehl <>, "" <>
To: Alex Huang Feng <>
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Subject: Re: [netconf] RFC8639 capability on https-notif receiver implementation
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[CC-ing NETCONF WG mailing list]

Hi Alex,

Thanks for reaching out!

> I am part of Unyte team and we are now implementing and testing the https-notif protocol on the draft <>
Always good to know about independent implementations in the works.

> We have implemented a library in C for the receiver and are planning to publish it as an open-source receiver implementation soon.

Nice contribution  - which capabilities will it support?

[be aware that there is an ongoing discussion regarding how capabilities should be supported: <>]

> We have some questions about the rfc-8639 capability (supporting the state machine defined in the rfc 8639).
> As I understood in the draft, https-notif receiver is not assumed to be a netconf/restconf server


> and as I read in the rfc-8639, the state machine is implemented in the publisher.
> I'd like to know how does this capability impacts the receiver implementation.

Hopefully the RFC 8639 authors can chime in, but my understanding is that the various notifications (subscription-started, subscription-modified, etc.) enable the receiver to maintain a local copy of the state machine, in order to know how to internally-dispatch notifications?

> In the draft: 
> Note that, for RFC 8639 <> configured subscriptions, the very first
>    notification must be the "subscription-started" notification.
> Does this mean that on the receiver side, the first "/relay-notification" notification we receive is the "subscription-started" rpc body ?


> Do we need to save a state in the receiver for later interaction ? Or the RFC 8639 support is just the first notification with the rpc ?

See previous comment, but my understanding is tenuous and hope others to chime in.

> Another observation on the draft, in the example 3.4, the json body for the GET capabilities is not valid (a colon is missed after the "receiver-capabilities").

Thanks!  Normally we run all code blocks through validation, but some of the code blocks in this draft elude that given the use of a pseudo YANG module...

> Looking forward to hearing from you,
> Alex Huang Feng
> INSA de Lyon | INSA Télécom