Simon,
I think the gotcha with CPM in this scenario is its a great tool for determining "this has happened" but not so great for building a mitigation solution.

Is CPM driven off of CDR's or off of the SAS datastream or some other source?

If its CDR driven you will be blind to this problem because you wont be measuring calls that are rejected due to lack of capacity(no cdr cut). If its driven off of SAS data you will get the missed/incomplete call stats but at the cost of speed (multiple orders of magnitude more data than CDR's)

It would be interesting to hear if this perhaps uses a different datasource. Perhaps there is a facility in perimeta that informs this better than CFS data sources.

-Ryan

On 8/18/2014 3:36 PM, Simon Dredge wrote:
I know many meta-users like the new-ish call pattern monitor. It uses weighted 
profiling benchmarking algos similar to NBAD:

http://www.metaswitch.com/sites/default/files/Metaswitch-Call-Pattern-Monitor.pdf

Cheers,


Simon.


-----Original Message-----
From: VoiceOps [mailto:[email protected]] On Behalf Of Ryan 
Delgrosso
Sent: Monday, August 18, 2014 1:53 PM
To: ECG - Mark Lindsey
Cc: [email protected]
Subject: Re: [VoiceOps] Hackers Crash Clay Co. Phones ...

I dunno that's a slippery slope. Im not a proponent of putting management of 
your network services into someone elses hands, especially things like this 
where the service provider should have visibility into what they are or are not 
admitting.

Agreed on your synopsis of call admission control, the border should be able to 
make these decisions rapidly, freeing up softswitch resources to actually serve 
customers.

This sounds like good territory for an acme SPL plugin, possibly in conjunction 
with this enum extension
http://tools.ietf.org/html/draft-kaplan-enum-source-uri-00 unfortunately i dont 
see a clear path for this in the TDM world but my exposure there is limited. It 
would seem like a good solution might be using ENUM (with source URI) to build 
statistics centrally based on calling/called numbers and then forcing the ENUM 
response once thresholds are hit to illicit an appropriate decline message for 
flagged invites with a retry-after interval allowing you to effectively 
throttle specific call scenarios assuming your origination carriers will behave 
correctly.

2 of the examples we discussed previously were:

1: Social media death star. Justin biebers (or anyone else with millions of rabid 
followers) twitter account  (53.7M followers) gets hacked and attacker tweets "Call 
this number for free tickets" or similar.

2: T-DOS using stolen sip accounts effectively turning other service providers 
into a death star. More damage per source number (higher CPS than social media 
per attacker but less distributed source). This one seems much easier to create 
given the ease with which stolen sip accounts can be acquired, and harder to 
mitigate if the stolen accounts support callerID spoofing.

Both of these situations are exacerbated by LCR resellers creating at times 
10-20 invites from 1 due to route advancing when the destination is truly 
congested, which gets worse when the LCR resellers in turn have resellers in 
route etc etc.

Of course any solution needs to have provisions for conveying congestion 
control to the originating network so they stop route advancing.


I think this has commercial viability for access providers protecting
their customers business interests and for implementers designing
solutions but perhaps not so much in a carrier to carrier capacity
(beyond appropriate support of signaling congestion control).


On 8/18/2014 12:48 PM, Mark R Lindsey wrote:
Ryan, does it seem as though TDoS will be most effectively addressed by the 
origination companies?  i.e., the guys with the TDM trunks to the local 
tandems, such as incumbents, Verizon, Level(3).

It seems to me that some use of statistics could probably make reasonable 
guesses about whether a given PSTN origination call is likely to be legitimate 
(for a call from A to B). For example, I'll bet you could make a good start 
looking at numbers and geographic areas:

        -- Has telephone number A called to telephone number B before? Or B->A ?

        -- Has GeographicArea(A) called to telephone number B before? Or 
GeographicArea(B) -> A?

The more you know about telephone numbers A and B, the more you could guess 
about the likelihood that a given call is legitimate.

And getting good at this should be a competitive advantage, just as effective 
anti-spam is an advantage elsewhere. Vendors that build the edge gear -- in 
particular, the SBC and TDM SS7 gateway vendors -- should be leading the way.

And wholesale carriers could take some advantage and make it broadly available. For 
example, let's say Verizon came along and said, "Here's a reason to port your 
numbers from Level(3) to us: When you're under attack, we're going to be smart about the 
ways we selectively admit calls to your network."



[email protected] +1-229-316-0013 http://ecg.co/lindsey
On Aug 18, 2014, at 13:52 , Ryan Delgrosso <[email protected]> wrote:

IP DDOS and TDOS are really two different problems but yes we as ITSP's and 
CLECs living in the IP space are absolutely susceptible to both.

Ive done a fair amount of research into both of these topics and we have seen 
varying cases of both, but usually IP DDOS steals the spotlight because the 
numbers are bigger and the effects are usually more widespread whereas a TDOS 
attack is rarely felt by anyone that doesn't live in the affected region or 
isn't actively trying to call the victim, and usually telcos keep these issues 
pretty close to the chest.

I expect this sort of attack is going to increase in magnitude in the coming 
24-36 months as attackers figure out how to wield it. Mark Collier gave a very 
interesting talk at one of the CFCA events on this topic, though the focus was 
on the enterprise victim, but the lessons are really the same. There just arent 
really any good tools to mitigate this sort of attack today, especially at the 
carrier level.

-Ryan

On 8/18/2014 6:30 AM, Matt Yaklin wrote:
It seems like almost every telephone company can be hit like that
except the ?largest?...

A denial of service attack by simply calling so many times it
fills up their main trunks.

And we saw how the large IP colo providers handle this for customers
who get dos'd. The amount of bandwidth they have is staggering and
they still cannot guarantee you will stay up if a ?skilled? attacker
wants you down. So you keep throwing money at it until you are
so well established online that you look at your monthly bill and
want to puke.

matt

On Mon, 18 Aug 2014, Frank Bulk wrote:

http://www.wibw.com/home/headlines/Hackers-Behind-Phone-Outage-In-Clay-County-271463051.html?ref=051

Painful issue for Big River Telephone!

Frank



_______________________________________________
VoiceOps mailing list
[email protected]
https://puck.nether.net/mailman/listinfo/voiceops
_______________________________________________
VoiceOps mailing list
[email protected]
https://puck.nether.net/mailman/listinfo/voiceops
_______________________________________________
VoiceOps mailing list
[email protected]
https://puck.nether.net/mailman/listinfo/voiceops

_______________________________________________
VoiceOps mailing list
[email protected]
https://puck.nether.net/mailman/listinfo/voiceops

Reply via email to