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

From: "Brian Raymor (MS OPEN TECH)" <[email-masked]>
Date: Wed, 24 Jun 2015 22:11:36 +0000

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

> Section 6 - Sentence in second last paragraph -  
> "In response to this request, the push service SHOULD return link references to the push and receipt subscribe resources, plus expiration information" 
> Are these the original URL's generated by the PS (i.e. /p/JzLQ3raZJfFBR0aqvOMsLrt54w4rJUsV and /receipts/xjTG79I3VuptNWS0DsFu4ihT97aE6UQJ) 
> or are these the corresponding uri's generated in response to the application server's messages (i.e. r/3ZtI4YVNBnUUZhuoChl6omUvG4ZM9mpN and
> /d/qDIYHNcfAIPP_5ITvURr-d6BGtYnTRnk). 

The link references are the urn:ietf:params:push and urn:ietf:params:push:receipt returned in the Subscription response.

> Also I'm assuming here that the "expiration information" refers to the expiration info of the push messages 
> (i.e their TTL), correct?

I agree that "expiration information" is ambiguous in this context. The reference is to subscription expirations. 
For the moment, Martin has added a small clarification:
  https://github.com/unicorn-wg/webpush-protocol/commit/181b620837aa39276b0a23b1a02d66f5f145cd0c

This is another case that could be clarified with an example.

---

From: Darshak Thakore <[email-masked]>
Date: Tue, 30 Jun 2015 23:22:30 +0000

Thanks for the clarification Brian.
So I¹m trying to understand why is it needed to send the ³:push² and the
³:push:receipt² URI¹s when the ³Prefer: wait=0² is sent by the UA?
Is the expectation that those URI¹s will expire after that particular
connection is concluded (I.e. After all undelivered push messages have
been delivered)?
Or is there some other purpose that I¹m missing ?

Darshak

On 6/24/15, 4:11 PM, "Brian Raymor (MS OPEN TECH)"
<[email-masked]> wrote:

>> "In response to this request, the push service SHOULD return link
>>references to the push and receipt subscribe resources, plus expiration
>>information" 
>> Are these the original URL's generated by the PS (i.e.
>>/p/JzLQ3raZJfFBR0aqvOMsLrt54w4rJUsV and
>>/receipts/xjTG79I3VuptNWS0DsFu4ihT97aE6UQJ)
>> or are these the corresponding uri's generated in response to the
>>application server's messages (i.e. r/3ZtI4YVNBnUUZhuoChl6omUvG4ZM9mpN
>>and
>The link references are the urn:ietf:params:push and
>urn:ietf:params:push:receipt returned in the Subscription response.
>
>I agree that "expiration information" is ambiguous in this context. The
>reference is to subscription expirations.

---

From: Martin Thomson <[email-masked]>
Date: Tue, 30 Jun 2015 16:31:44 -0700

> ³:push:receipt² URI¹s when the ³Prefer: wait=0² is sent by the UA?

This means that a client need only hold the subscription URL; it can
re-learn the push and receipt subscribe resources by making this
request.

And inclusion of these links need not be based on receiving Prefer:
wait=0, though other requests might longer to complete than would be
ideal (or useful).

---

From: Darshak Thakore <[email-masked]>
Date: Wed, 1 Jul 2015 00:30:53 +0000

Ahh.. Thanks. 
In the light of this explanation, it seems to be just some word-smithing
problem.

Might I suggest that you move the sentence:
"A user agent can request the contents of the push message subscription
resource immediately by including a Prefer header field [RFC7240] with a
"wait" parameter set to “0.”

to be after the sentence:

"In response to this request, the push service SHOULD return link
references to the push and receipt subscribe resources, plus expiration
information for the subscription."

That way the recommendation for the PS to send the link references does
not get associated (as I mistakenly did) with the request that contains
“Prefer: wait=0” header.

Darshak

---

From: Martin Thomson <[email-masked]>
Date: Tue, 30 Jun 2015 21:06:48 -0700

An excellent suggestion, thanks:
https://github.com/unicorn-wg/webpush-protocol/commit/274723b4d52cd1baf