[VOIPSEC] VoIP Attack : How feasible

Volker Tanger vtlists at wyae.de
Fri Jul 28 13:05:56 CDT 2006


On Fri, 28 Jul 2006 15:34:19 +0800
Simon Horne <s.horne at packetizer.com> wrote:

> VPNs do not provide end to end authentication.

Maybe if you are using net2net VPNs - if using host2host (end2end)
VPNs, then they do. At least for the IP connection, that is.


> VPNs do not provide end to end encryption.

See above.


> VPNs do not provide efficient NAT Traversal.

If using UDP-encapsulated IPSec or OpenVPN, they do. It's just plain UDP
traffic then, no problem to NATify in any way.


> traversing NAT which excludes methods like UPnP from being a
> functional solution

*ahem*  UPnP is not a functional solution for quite a lot of stuff
it does. It is especially unusable for corporate environments - with
UPnP-enabled "firewalls" any client can configure any port-forwarding
from outside to inwards which is exactly what you do not want on a
corporate firewall.


> In 10 years of VoIP NAT and security development and after truckloads
> of  publicized RFC's and white papers why are we still talking about
> VPN's?  Surely there must be better solutions that can be deployed
> today. There is,  just they are not available in SIP.

...or any other VoIP protocols that rely on symmetric RTP as transport
mechanism (which needs helper protocols and stuff for NATability).

Bye

Volker


-- 

Volker Tanger    http://www.wyae.de/volker.tanger/
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