Subject: [Sipping] Expiration of permissions in consent

From: Gonzalo Camarillo <[email-masked]>
Date: Wed, 23 Nov 2005 14:38:55 +0200

Folks,

there is a last open issue in the consent requirements draft:
http://www.ietf.org/internet-drafts/draft-ietf-sipping-consent-reqs-01.txt

The open issue has to do with requirement number 7:

    REQ 7: It shall be possible for the users to specify that permissions
       are time limited, and must be refreshed after expiration.

The idea is that the relays storing consent state for a particular user 
do not need to be in the same administrative domain as the user. 
Therefore, the state information to be stored should be as little as 
possible. That's why we have removed allowed operations from the 
permission documents.

Now, storing expiration information requires a little more logic in the 
relay, but, on the other hand, having permissions that expire could be a 
useful feature in some scenarios.

The open issue is: do we keep or remove REQ 7?

Note that when you subscribe to an email mailing list, you do not 
typically set any expiration time for your subscription. So, I lean 
towards removing REQ 7 but do not have a strong opinion.

Opinions?

Thanks,

Gonzalo

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---

From: "Henry Sinnreich" <[email-masked]>
Date: Wed, 23 Nov 2005 08:27:20 -0600

I vote to keep REQ 7 so that forgetful users would not be abused. 
This is similar to many IETF mailing lists renewals.
Soft state has many advantages.

Thanks, Henry

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf
Of Gonzalo Camarillo
Sent: Wednesday, November 23, 2005 6:39 AM
To: sipping
Cc: Dean Willis
Subject: [Sipping] Expiration of permissions in consent

Folks,

Opinions?

Thanks,

Gonzalo

---

From: David R Oran <[email-masked]>
Date: Wed, 23 Nov 2005 09:58:29 -0500

> Soft state has many advantages.
True, but in today's usage the mailing list maintainance sends out  
notifications for to remind that the subscription is active. It isn't  
a notification of impending removal that has to be responded to, nor  
a mechanism that allows subscriptions to silently expire.

I agree that soft state has advantages, but exploders have a lot of  
hard state already so adding some form of expiration may make sense.  
On the other hand, it may be useful to build this into the  
application on that is using the consent framework rather than the  
consent operations themselves.

I think the feature is useful, but I'm not sure delaying te consent  
framework in order to satisfy this is the right tradeoff.

Dave.

---

From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 23 Nov 2005 10:36:07 -0500

I think this requirement was more appropriate before we had fully 
thought through roles here. In the framework now, we are seeking to put 
minimal capabilities in the relay in the "other network", and leaving 
more complicated permissions in the servers in a user's own network. 
Supporting of time-limited permissions means that the server needs to 
worry about refreshes, making it have to do more work.

So, my vote is to remove.

-Jonathan R.

-- 
Jonathan D. Rosenberg, Ph.D.                   600 Lanidex Plaza
Director, Service Provider VoIP Architecture   Parsippany, NJ 07054-2711
Cisco Systems
[email-masked]                              FAX:   (973) 952-5050
http://www.jdrosen.net                         PHONE: (973) 952-5000
http://www.cisco.com

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From: Dean Willis <[email-masked]>
Date: Wed, 23 Nov 2005 22:46:22 -0600

> towards removing REQ 7 but do not have a strong opinion.

The fact that subscriptions to email lists don't expire is a large  
reason why email list operators have resorted to periodic "probe"  
messages to clean up their state bins.

Reality check: Nothing lasts forever. Protocol designs that assume  
otherwise are bound to be slapped by reality.

I suggest keeping the requirement. I'd go so far as to make time- 
bounding permissions a MUST.

--
Dean

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From: Miguel Garcia <[email-masked]>
Date: Thu, 24 Nov 2005 10:30:33 +0200

If we compare we today's e-mail, I am subscribed to a mailing list that 
sends me e-mail to my inbox, which I can access from any device with the 
appropriate connectivity.

If we put expiration time to the permisions, then I would need to 
refresh these permisions from a given UA when the permision is over. If 
I change the UA, I would need to reconfigure with all the permisions I 
had granted in the past, to keep refreshing them. And what about if this 
other UA does not support the consent framework operations? Or I would 
need a synchronization mechanism that keeps me informed across different 
UAs of the expiration time, when there isn't an active subscription.

In the meantime, when my permission is expired, people might be try to 
contact the list (including me), but because my permision expired, I 
will not receive those requests. This creates a discontinued service and 
bad user experience.

In my opinion, there is too much hassle here ... I would rather go for 
something similar to how mailing lists work today, which effectively 
means removing requirement 7.

/Miguel

-- 
Miguel A. Garcia           tel:+358-50-4804586
sip:[email-masked]
Nokia Research Center      Helsinki, Finland