Re: [rtcweb] UDP transport problem

On Fri, Feb 14, 2014 at 10:24 AM, Harald Alvestrand
<harald@alvestrand.no> wrote:
> On 02/14/2014 03:42 PM, Cb B wrote:
>>
>> > It's especially depressing in that we put significant effort into
>> reducing the likelihood that WebRTC could be used for DDoS attacks.
>> >
>> > I will note that blocking UDP (or massively-rate-limiting it) will
>> have all sorts of nasty effects on all forms of VoIP.  TCP-entrained
>> VoIP can evade that, but at a serious cost to call quality.  Surely
>> the operators know this.
>> >
>>
>> Agreed on all points. My view is one related to the basic requirement
>> of keeping the network up.  I hope i have provided enough reference
>> points to make the magnitude of the problem clear as well as how
>> history has shown protocols get blocked (smtp)
>>
> This SMTP example doesn't match what I've seen happen.
>
> SMTP is not blocked by any backbone service provider I know of.
>
> Outgoing SMTP on port 25 is commonly blocked by firewalls that think
> they don't have servers behind them (hotels are notorious in this
> aspect). That's why the submit port is popular (and deployed with
> authentication). The main concern isn't DDOS attacks, it's being blamed
> for spam.
>

Spam is a type of attack.  It is an L7 attack as opposed to a volume attack.

The largest broadband ISP in the USA blocks port 25, i provided this
info in my first email.

http://customer.comcast.com/help-and-support/internet/email-port-25-no-longer-supported/

> I've not seen any report of a DDOS attack that used port 25 for a
> traffic-volume-based attack (although intentional or unintentional DDOS
> attacks on mail servers are too common to care about).
>
> Given that I still haven't seen a report that leads me to belive we'll
> ever see a proposal that seriously proposes blocking all UDP traffic on
> the Internet - I continue to disbelieve the premise, so it's not
> surprising that I disagree with the conclusion.
>

That's fine.  It is not my goal to block UDP or save WebRTC.  I am
just submitting information that i have and connecting the dots that
are in front of me.  The future may show that i am too pessimistic or
not enough.

CB

> --
> Surveillance is pervasive. Go Dark.
>
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