Subject: RE: [Sipping] draft-niccolini-sipping-feedback-spit-00

From: "Samir Srivastava" <[email-masked]>
Date: Wed, 22 Mar 2006 14:01:08 -0600

Consent framework etc also needed. There is no _THE_ solution to SPAM.

Let us take a case of Voice Mail. Spammed calls are directed to voice
mail server for different users. And If the one of the voice mail user
gives the feedback, then searching on the signature obtained, Voice Mail
Server can transfer these voice mails to the "Suspected SPAM" folder for
other receipents . It might do some media searching also with advanced
media inspection engines (where you have filters for background Noise
etc, which is stated as demerit of media inspection in sip-spam draft ).
Refer http://www.speechatsri.com/products/dynaspeak.shtml too. I don't
have hands on experience on  this righ now, how good these filters are.
Voice mail servers doesn't require
realtimeness.

We are concerned with Voice here. What about the IM SPAM using SIP ? 

I am thinking of a header for indicating likeliness of SPAM with some
qValue (0.1 -1). My edge 
proxy (SBC / B2BUA ) does SAML assertion  and using its algorithmic
crieteria assigns the qValue for likeliness of SPAM. For each call
passing SAML to end device is not good especially where air time is
involved. Complete SAML is passed using content indirection with http
URL etc. User can take a detailed look on SAML assertion by fetching the
contents, if he wants.

Thx
Samir

-----Original Message-----
From: Dan Wing [mailto:[email-masked]] 
Sent: Wednesday, March 22, 2006 7:31 AM
To: 'Saverio Niccolini'; [email-masked]
Cc: 'Sandra Tartarelli'; [email-masked]; 'Martin Stiemerling'
Subject: RE: [Sipping] draft-niccolini-sipping-feedback-spit-00

> answers are inline.
> 
> > I don't feel standardizing this is helpful for SPIT.  There has been

> > years of research into email antispam.  While they have content and 
> > subject lines (and SIP doesn't),
> 
> As also Samir said: SIP do have subject headers.

SDP has s=, too, but neither are used much especially on SIP phones.

> I agree with you that we do not have the content in voice for
> filtering: that is why we need the feedback even more.

We disagree on what's needed to reduce the problem of spam / spit.

> > the problem of 'blacklisting' someone is very complex (how does one 
> > get off the list, what if a blacklisted person is a legitimate 
> > customer of a legitimate company [wants to get their car repaired at

> > the local car dealer, or wants to get a pizza delivered] but that 
> > person earlier in the day was harassing their congressman's office 
> > and got blacklisted?
> 
> We are not talking about blacklisting only in the draft.
> And anyway
> a feedback may also not turn into a blacklisting action (it depends on

> how you want to use the feedback).
> Blacklisting is one of the methods for SPIT prevention, but it is not 
> the only one.
> Let's think of a reputation system, it may also profit from feedback 
> information.

I'm quite familiar with existing email spam prevention techniques,
blacklisting, spam scoring (SpamAssassin and the like), community spam
reporting (Couldmark and Brightmail and the like), and am aware of
techniques used by AOL, Yahoo, and GMail to reduce the spam that users
see.

I'm not convinced the information you're suggesting to report is
sufficient for these systems.  I'm asking if you have interacted with
those groups, or with IETF's own DKIM group, to see what reputation
systems need.

To date, there is no single reputation system 'interface' for email.
Email, and email spam, has been around for a decade.  

If your intent is to provide input into a reputation system, it seems
good to build on what has been done for these systems and how those
systems handle false reports.  For example, in email, it's very common
for someone to get on a mailing list and later want to get off the
mailing list.  Many of those people click on the 'spam' button rather
than the 'unsubscribe' link.  Which makes some sick sense -- afterall,
it was lore that clicking on 'unsubscribe' told the spammers they had
found an active email address.  Back to existing PSTN phones, I belong
to frequent guest programs for various hotels and they sometimes call me
for special deals at specific hotels.  I can imagine that if some people
are in that same situation they might simply click 'spam' -- causing the
same improper feedback to a reputation system as with mailing lists.

> > I don't think we want to go there, at least not in SIP or in 
> > SIPPING.
> > 
> > Whoever does go there can tell us what information they find useful.

> > And I'm sure it'll be sip-identity and some codification of the 
> > claimed SPIT offense.
> 
> I am pretty sure SIP identity can help in SPIT prevention but I do not

> see it as THE method.

I agree, it isn't the only method.

> And it has still some problems
> (see Section 6 of draft-ietf-sipping-spam-02).

This is where SIP needs to look over to DKIM for help.  One of the
issues in section 6 of that I-D is that it's impossible to determine if
missing SIP Identity was because the originating domain doesn't use SIP
Identity, or if it was stripped off.  DKIM provides a way to determine
if a remote domain signs its messages by doing a DNS query to determine
their policy.  SIP could borrow this idea, with the necessary
modifications (SIP is obviously not email).

> My opinion is that we need more methods to be combined if we want to 
> be effective in SPIT prevention and we have to leverage what email has

> to offer (see Section 5 of draft-ietf-sipping-spam-02) and feedback is

> used in email systems (my web.de account has a feedback mechanism 
> built-in)

My opinion remains that it's too early to standardize this yet.

-d

> Cheers,
> Saverio
> 
> 
> > 
> > -d
> > 
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_______________________________________________
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This list is for NEW development of the application of SIP
Use [email-masked] for questions on current sip
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