Re: [Speermint] AD review: draft-ietf-speermint-voipthreats-05

[Jan Seedorf <[e-mail]>]

Dear Gonzalo,

Thanks, great,

See you in Prague,

 - Jan

> -----Original Message-----
> From: Gonzalo Camarillo [mailto:[e-mail]]
> Sent: Donnerstag, 3. Februar 2011 10:01
> To: Jan Seedorf
> Cc: [e-mail]; Saverio Niccolini; Eric Chen;
> [e-mail]
> Subject: Re: [Speermint] AD review: draft-ietf-speermint-voipthreats-05
> 
> Hi Jan,
> 
> thanks for addressing the comments. I have just requested an IETF LC for
> this draft.
> 
> Cheers,
> 
> Gonzalo
> 
> 
> On 25/01/2011 3:14 PM, Jan Seedorf wrote:
> > Dear Gonzalo,
> >
> > Thanks for your - indeed valid - comments on our -06 version of draft-ietf-
> speermint-voipthreats. Sorry for taking a while, your comments resulted in
> quite some changes in the draft. I just posted a new -07 version, let me
> explain below how we think we addressed your comments in this version:
> >
> >>> While message modification and eavesdropping is included in the
> >>> threats against SF and MF, they do not seem to appear in the threats
> >>> against LRF and LUF. Why?
> > Indeed message modification and eavesdropping are threats also for the LUF
> and LRF. We assumed those addressed with "confidentiality" and "integrity". We
> added some more text now, e.g. specifically mentioning "eavesdropping" and
> "message modification" under "confidentiality" and "integrity", respectively,
> for the LUF and LRF. For us, it was implicit that when one talks about
> confidentiality he/she indirectly talks about "eavesdropping", and when one
> talks about integrity he/she indirectly talks about "message modification".
> Anyway, we hope the text now explicitly makes this clear.
> >
> >> Also, the reasons why Section 4.5 recommends TCP over UDP are still not
> >> clear. UDP over DTLS would meet the requirements in both Sections 3.2
> >> and 4.5.
> > This is a very good point, which caused changes in section 4.5, 3.2, and in
> some other parts. At the time we started writing this draft back in 2007,
> RFC4347 on DTLS was less than a year old and there was no mature
> implementation of DTLS at the time.  Companies designing NGN at the time did
> not consider DTLS for the same reason. Since it has been more than three
> years, nowadays there seem to be quite a few DTLS implementations (at the IETF
> privacy workshop in Dec., I talked with Eric Rescorla about this and he
> confirmed that some stable implementations exist by now). We now updated the
> sections, saying that transport layer security can be either DTLS or TLS,
> depending on the use of the underlying transport protocol (UDP or TCP). Thus,
> we also do not recommend TCP over UDP anymore, and the section was renamed to
> "4.5 Secure Exchange of SIP messages". Accordingly, the former section "4.13.
> Encryption and Integrity Protection of Signaling Messages" is now obsolete and
> we had
>  to update also section 3.2., mentioning DTLS as an alternative to TLS.
> >
> > We hope the draft is in better shape now and that all your comments have
> been addressed.
> >
> > Sorry again for taking so long,
> >
> >  - Jan
> >
> >
> >> -----Original Message-----
> >> From: [e-mail] [mailto:[e-mail]] On
> Behalf
> >> Of Gonzalo Camarillo
> >> Sent: Dienstag, 16. November 2010 12:49
> >> To: [e-mail]
> >> Subject: Re: [Speermint] AD review: draft-ietf-speermint-voipthreats-05
> >>
> >> Hi,
> >>
> >> thanks for having submitted a new revision of this draft:
> >>
> >> http://tools.ietf.org/html/draft-ietf-speermint-voipthreats-06
> >>
> >> This revision addresses most of my comments below. However, I do not
> >> think I got an answer to the following question:
> >>
> >>> While message modification and eavesdropping is included in the
> >>> threats against SF and MF, they do not seem to appear in the threats
> >>> against LRF and LUF. Why?
> >>
> >> Also, the reasons why Section 4.5 recommends TCP over UDP are still not
> >> clear. UDP over DTLS would meet the requirements in both Sections 3.2
> >> and 4.5.
> >>
> >> Thanks,
> >>
> >> Gonzalo
> >>
> >>
> >> On 29/09/2010 5:15 PM, Gonzalo Camarillo wrote:
> >>> Hi,
> >>>
> >>> a couple of days ago I received a publication request for the following
> >>> draft:
> >>>
> >>> https://datatracker.ietf.org/doc/draft-ietf-speermint-voipthreats/
> >>>
> >>> Here you have my AD review of the draft (see below). The authors should
> >>> be able to address all my comments fairly quickly. As soon as they
> >>> revise the draft I will initiate its IETF LC.
> >>>
> >>> Thanks,
> >>>
> >>> Gonzalo
> >>>
> >>>
> >>> draft-ietf-speermint-voipthreats-05
> >>>
> >>> Expand acronyms on their first use (e.g., SPEERMINT in the title and
> >>> VoIP in the Introduction).
> >>>
> >>> The Abstract and the Introduction attempt to explain the relationship
> >>> between this draft and draft-ietf-speermint-requirements. However,
> >>> Section 3.1 does a better job at that. Could you please clarify in the
> >>> Introduction that the requirements in draft-ietf-speermint-requirements
> >>> were derived from the threats documented in this draft? Also, please
> >>> clarify that in addition to be the base for those requirements, this
> >>> draft provides countermeasures to meet those requirements. Any SPEERMINT
> >>> expert will probably understand that by reading the Abstract and the
> >>> Introduction but clarifying those points will help readers who have not
> >>> been that involved in the process.
> >>>
> >>> While message modification and eavesdropping is included in the
> >>> threats against SF and MF, they do not seem to appear in the threats
> >>> against LRF and LUF. Why?
> >>>
> >>> Section 4.5 recommends to use TCP instead of UDP. That advice is great,
> >>> but the reasons Section 4.5 discusses are not that strong. The fact that
> >>> the linux kernel has improved is irrelevant if an operator uses
> >>> non-linux boxes. Also, an operator using UDP over IPsec, for instance,
> >>> will not face the problems described there. The main recommendation in
> >>> Section 4.5 seems to actually be to use an integrity protection
> >>> mechanism. Clarifying that section would be useful.
> >>>
> >>> [refs.sbcfuncs] has been published as RFC 5853
> >>>
> >>> A few references only include the title and the author fields. Adding
> >>> the venue where they were published would be useful.
> >>>
> >>
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