Hi, I'm dealing with presence right now. I've read full OMA and RCS specifications/proposals/guidelines for presence and XCAP but I don't feel comfortable with some parts of them.
So let me to explain the question (it involves the sr/kamailio presence module behavior for a future re-design in which I want to participate):
In presence/XCAP/XDM there are three ways bob can deny alice to see his presence status (by modifying the XCAP documents according):
1) Ignore alice's request. This is, bob doesn't "allow" neither "blocks" alice, so alice just gets the first NOTIFY from the server with: Subscription-Status: pending After some long time the server will send: Subscription-Status: terminated ; reason=expired
2) Block alice by invoking a "block" action. This means that alice receives a NOTIFY from the server with: Subscription-Status: terminated; reason=rejected This is: alice *knows* that she has been explicitely blocked by bob.
3) Polite-block alice by invoking "polite-block" action. In this way the presence server generates a spoofed NOTIFY for alice containing "offline" information but the header: Subscription-Status: active This is: alice *things* she has been allowed by bob and bob it's offline right now (not true).
Well, in real IM/presence world (MSN, Skype, XMPP, Yahoo...) option 2 doesn't exist, am I right? This is, if you block an user he doesn't know that you have blocked him. Instead just options 1 or 3 are used (and in some networks just option 1).
Do you see any advantage in point 2? Personally I don't see it and it just introduces too much complexity for presence/XCAP/XDM client developers.
I would appreciate your opinnions about it. Thanks.
Am 18.02.2010 18:12, schrieb Iñaki Baz Castillo:
Hi, I'm dealing with presence right now. I've read full OMA and RCS specifications/proposals/guidelines for presence and XCAP but I don't feel comfortable with some parts of them.
So let me to explain the question (it involves the sr/kamailio presence module behavior for a future re-design in which I want to participate):
In presence/XCAP/XDM there are three ways bob can deny alice to see his presence status (by modifying the XCAP documents according):
- Ignore alice's request. This is, bob doesn't "allow" neither "blocks"
alice, so alice just gets the first NOTIFY from the server with: Subscription-Status: pending After some long time the server will send: Subscription-Status: terminated ; reason=expired
- Block alice by invoking a "block" action. This means that alice receives a
NOTIFY from the server with: Subscription-Status: terminated; reason=rejected This is: alice *knows* that she has been explicitely blocked by bob.
- Polite-block alice by invoking "polite-block" action. In this way the
presence server generates a spoofed NOTIFY for alice containing "offline" information but the header: Subscription-Status: active This is: alice *things* she has been allowed by bob and bob it's offline right now (not true).
Well, in real IM/presence world (MSN, Skype, XMPP, Yahoo...) option 2 doesn't exist, am I right? This is, if you block an user he doesn't know that you have blocked him. Instead just options 1 or 3 are used (and in some networks just option 1).
Do you see any advantage in point 2? Personally I don't see it and it just introduces too much complexity for presence/XCAP/XDM client developers.
I think option 2 would be nice for debugging, as Alice immediately knows that she is blocked and does not have to debug why the subscription does not work.
Of course, from privacy point of view I would also prefer options 1 and 3. IMO option 1 is better. Because with option 3 Alice would think that Bob is really offline, whereas option 1 just signals "nothing" and thus tells Alice that the information is just not available.
regards klaus
I would appreciate your opinnions about it. Thanks.
Hi, I'm sorry becvause I did cross-posting to kamailio-dev and sr-dev, so I resend to both maillists
El Viernes, 19 de Febrero de 2010, Klaus Darilion escribió:
I think option 2 would be nice for debugging, as Alice immediately knows that she is blocked and does not have to debug why the subscription does not work.
Of course, from privacy point of view I would also prefer options 1 and 3. IMO option 1 is better. Because with option 3 Alice would think that Bob is really offline, whereas option 1 just signals "nothing" and thus tells Alice that the information is just not available.
Yes, but as I told in kamailio-dev trhead, the problem of option 1 is that it involves "pending" status. A transition from "active" (allowed user) to "pending" (more-or-less blocked) is not possible. Also the pending status expires in the server so Alice would resend the SUBSCRIBE and Bob should ignore it again and again.
Please check the mail I've sent to kamailio-ev a few minutes ago.
Thanks a lot for your help.
-
Iñaki Baz Castillo -
Klaus Darilion