Re: [sipcore] draft-ietf-sipcore-callinfo-spam-01 - SIP entities

[Henning Schulzrinne <[e-mail]>]

There are four likely models:

* the call type (and spam-quotient) information may be shown to users, but most likely when reviewing voice mail, not a ringing call (where a simple binary indicator is probably more suitable, derived from information in the draft, possibly)
* various end system call handling algorithms, e.g., the semi-automated 'do not disturb' features in Android and iOS, so that, for example, non-personal calls would be directed to voice mail after 10 pm or during meetings.
* PBX and similar corporate systems that filter and manage calls, whether by corporate policy (e.g., to prevent Microsoft "support" calls) or by user preference
* as a call-out to a third-party system - the call information is proxied to a third party system, which then add the call-info labeling to the call

In all cases, the information in the header would seem to be, at most, be indirectly reflected in the appropriate user interface.  But, in my view, you need to provide the end system and UI with a bit more data so that they can do the filtering and UI tailoring. It's easy to turn a spam score into red and green, but you can't set red and green thresholds appropriate to the circumstances if the carrier has already made that decision.

The CNAM information seems complementary to this, although it might use some of the same type labeling. CNAM also seems to require far more originator cooperation (and a caller is unlikely to label itself as "spam"...).

Henning

-----Original Message-----
From: Richard Shockey [mailto:[e-mail]] 
Sent: Thursday, July 20, 2017 12:22 PM
To: Asveren, Tolga <[e-mail]>; Henning Schulzrinne <[e-mail]>; Paul Kyzivat <[e-mail]>; [e-mail]
Subject: Re: [sipcore] draft-ietf-sipcore-callinfo-spam-01 - SIP entities



The other issue is who is the intended recipient of the data?  Among those of us that are actively evaulating Call Validation Display options we see some differences.  What a consumer may need to see is vastly different from what a inbound call center agent or enterprise user should see and should call validation data be combined with other forms of calling party identity in a expanded  CNAM (calling party name) like service offering.  In the EU for example they have no experience at all with CNAM.  That has typically been a North Americian service. 

I understand the argument for a binary data display such as green check vs red octonganal stop like visual indicator and there are serious nuances in what type of text should be displayed. We are not there yet.   We are delving into the black arts of UI design here and we are simply going to have to do some experimentation to come up with answers and even then its clear that one size may not fit all.

In any event there is already a thoughtful discussion between the service provider community and some national regulators on what the options are.

..

On 7/19/17, 2:46 PM, "sipcore on behalf of Asveren, Tolga" <[e-mail] on behalf of [e-mail]> wrote:

    Agreed that this is somewhat about "philosophical aspects of priority". Having said that, I really feel not content with a fine-granularity indicator considering how in practice it would/could be generated especially considering all the operator/equipment/call scenario/deployment model combinations. It would be like, actually worse, than how sausages are prepared.
    
    I am not religiously advocating a change toward a binary indicator (i.e. I wouldn't consider the current model as something "wrong") but IMHO that would be a more practical way of getting something useful at the end; just my 2 cents.
    
    Thanks,
    Tolga
    
    -----Original Message-----
    From: Henning Schulzrinne [mailto:[e-mail]] 
    Sent: Wednesday, July 19, 2017 2:33 PM
    To: Asveren, Tolga <[e-mail]>; Paul Kyzivat <[e-mail]>; [e-mail]
    Subject: RE: [sipcore] draft-ietf-sipcore-callinfo-spam-01 - SIP entities
    
    This type of labeling is very common for email spam filters. It's essentially the same as "There's a 47% chance of rain today." Except that meteorologists are smart enough not to say 47%, but rather 50%.
    
    It is better than the "According to the polls, candidate H has an 89% chance of winning the election." (Any semblance of initials to real persons has a 1-in-26 chance of being made up.)
    
    Theoretically, unlike for elections and somewhat similar to the weather case, this is testable: You could take all the 50% spam or rain predictions, check with some reliable metric (human or rain gauge) whether the spam or rain happened and compare your results, i.e., roughly one in two such predictions should indeed turn out to be spam or rain. (It's more complicated than that, but we're getting pretty close to the philosophical debate of what probabilities mean when making predictions, which is apparently a rather unsettled scientific question.)
    
    To actually answer your question: I don't think this is useful except as a rough way for users to trade false-positive/false-negative penalties. For example, they may discard all 80%+ probability calls, route 30-80% calls to voicemail and ring the below-30% calls. The thresholds are arbitrary, but users may tune them based on experience ("all the calls in voicemail were spam, so I can go lower").
    
    Some people pack an umbrella when there's a 20% chance of rain, others are more willing to risk getting wet. By the way, it is well-known that meteorologists over-predict rain since nobody complains if they did not get soaked.
    
    Henning
    
    -----Original Message-----
    From: sipcore [mailto:[e-mail]] On Behalf Of Asveren, Tolga
    Sent: Wednesday, July 19, 2017 2:11 PM
    To: Paul Kyzivat <[e-mail]>; [e-mail]
    Subject: Re: [sipcore] draft-ietf-sipcore-callinfo-spam-01 - SIP entities
    
    Let me ask this question then:
    What would "spam with a likelihood of 47%" mean? Will the specification detail how this percentage need to be calculated? Otherwise how can the end-device take some action based on this value? One could argue that all these are "implementation dependent" but honestly I think this would just create confusion/chaos in practice and likely to be not useful.
    
    Thanks,
    Tolga
     
    
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