Re: Skype use obligation - Security x Productivity

[Roland Dobbins <rdobbins@cisco.com>]

On Jul 16, 2007, at 2:56 PM, M.B.Jr. wrote:

> Guess we need to hear some other professionals.
I disagree with this characterization - I don't think Skype's network  
behavior risks any certifications at all (for example, the Skype  
could be profiled using a NetFlow-based behavioral anomaly-detection  
system, for example, irrespective of its port/protocol selection),  
there's nothing in any of those standards which would seem to imply  
that, AFAICT.  The bigger risk with Skype, IMHO, is the 'supernode'  
functionality which can result in one's conversations being relayed  
by random nodes beyond one's control and/or one's own Skype nodes  
acting as a supernode relay for the calls of others.  It also uses a  
closed-source encryption scheme which hasn't been subjected to peer  
review.
There are some ways to restrict Skype functionality either using  
Skype and/or Skype partner add-ons as well as third-party solutions  
which can restrict host application behavior.  The supernode  
functionality, AFAIK, is hardcoded.
Another option would be something along the lines of a Skype-to-SIP  
gateway (I think there's at least one commercially available) which  
would allow your customer to use SIP handsets or softphones to  
communicate with the gateway, which would then proxy the calls to/ 
from Skype.
But making the assumption that the mere presence of Skype on the  
network would somehow result in loss of certification is a bit of a  
stretch, IMHO.
-----------------------------------------------------------------------
Roland Dobbins <rdobbins@cisco.com> // 408.527.6376 voice

       Culture eats strategy for breakfast.

               -- Ford Motor Company




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