Subject: Re: [Webpush] some comments and feedback on the draft-thomson-webpush-protocol-00

From: "Brian Raymor (MS OPEN TECH)" <[email-masked]>
Date: Fri, 19 Jun 2015 05:04:19 +0000

Thanks for the review feedback, Darshak. I will respond to each section in separate messages.

On Thursday, Jun 18, 2015, Darshak Thakore <[email-masked]> wrote:

> Section 4 - The first sentence in the last paragraph
> "A push service SHOULD provide the same receipt subscribe URI to user agents".
> I'm trying to understand what this means. If we are referring to the "https://push.example.net/r/3ZtI4YVNBnUUZhuoChl6omUvG4ZM9mpN" URI in
> the example in Section 4, how exactly does the push service provide this URI to the user-agent. 

Let me review the "how" first.

In addition to the URI for the push resource (urn:ietf:params:push), the push service also returns the URI for the receipt subscribe
resource (urn:ietf:params:push:receipt) to the User Agent during the subscription process. 
(https://tools.ietf.org/html/draft-thomson-webpush-protocol-00#section-3)

   The push server MUST provide a URI for a receipt subscribe resource
   in a link relation of type "urn:ietf:params:push:receipt".

In the examples, the receipt subscribe resource uses the https://push.example.net/receipts/xjTG79I3VuptNWS0DsFu4ihT97aE6UQJ URI.

The User Agent then forwards both the URI(s) its application server:

   An application-specific method is used to distribute the push and
   receipt subscribe URIs to the application server.

The application server can then use the receipt subscribe URI to create a receipt subscription
(https://tools.ietf.org/html/draft-thomson-webpush-protocol-00#section-4) to receive receipts
from the push server (https://tools.ietf.org/html/draft-thomson-webpush-protocol-00#section-6.2).

In the examples, the receipt subscription resource is https://push.example.net/r/3ZtI4YVNBnUUZhuoChl6omUvG4ZM9mpN which is
the URI you're referencing above.

> Is the intent to say that it should provide the same URI
> to a given application server? (I've marked this with the red arrow in the diagram)

Recently, Martin developed this section further to provide more context:
  https://github.com/unicorn-wg/webpush-protocol/commit/68c4c599314f9f4ca916831468ea7323605e6bcb

Does this offer more clarity and answer your question?

There were also earlier conversations on the rationale for the SHOULD statement:

https://github.com/unicorn-wg/webpush-protocol/commit/9fb7296585c7d69d1b84df837e1cf16c297ccb20#commitcomment-10675623

---

From: Darshak Thakore <[email-masked]>
Date: Fri, 19 Jun 2015 23:15:53 +0000

Hi Brian,
Thanks for the explanation. I also managed to catch up on the other email
exchanges and that clarifies it. The added suggested wording from Martin
also helps.

Darshak

On 6/18/15, 11:04 PM, "Brian Raymor (MS OPEN TECH)"
<[email-masked]> wrote:

>> I'm trying to understand what this means. If we are referring to the
>>"https://push.example.net/r/3ZtI4YVNBnUUZhuoChl6omUvG4ZM9mpN" URI in
>In addition to the URI for the push resource (urn:ietf:params:push), the
>push service also returns the URI for the receipt subscribe
>In the examples, the receipt subscribe resource uses the
>https://push.example.net/receipts/xjTG79I3VuptNWS0DsFu4ihT97aE6UQJ URI.
>
>from the push server
>(https://tools.ietf.org/html/draft-thomson-webpush-protocol-00#section-6.2
>).
>
>In the examples, the receipt subscription resource is
>https://push.example.net/r/3ZtI4YVNBnUUZhuoChl6omUvG4ZM9mpN which is
>https://github.com/unicorn-wg/webpush-protocol/commit/9fb7296585c7d69d1b84
>df837e1cf16c297ccb20#commitcomment-10675623
>
>