NC: ESP vs. oNCP : Which one offers the best security criteria?

[Seb_]

Hi,

One of my customers is asking us what is different in term of security when using ESP transport mode for NC instead of using the default oNCP.

My point of view is that ESP should be more secure because the symmetric encryption key is changed after a given time or a given amount of tranmitted data. This makes replay attacks much more complicated.

What is your opinion?

Thanks in advance

Seb

[Jickfoo_]

I'd vote for ESP for the simple fact that it uses udp.. Less prone to port scans and the like and it's faster.

[Kifah_ · Accepted solution]

Hi,

I think that there is not a big difference from the security view. ESP has a better performance than oNCP. So if you use VoIP i would recommend ESP.

Greetings

Kifah

[Seb_]

Ok, thanks for your opinion.

If somebody has a more detailled explanation, it will be the welcome.

Best regards

Seb

[Dan_Smart_]

ESP has 1.5X the performance of NCP. Use ESP always.

-=Dan=-

[applmott_]

I would not recommend always using ESP. In fact, there are cases where the packet size of ESP can do some very funky things to routers (WRT, DLINK). We have had numerous reports of faulty DNS, packet loss, etc. when using ESP transport mode. The benefit to using NCP/oNCP is that you have a lot more flexibility because it rides over TCP (connection-oriented, retransmission of lost packets) so if you don't need to run stream-dependent traffic like VoIP or streaming media, NCP can in fact be just as effective to the end-users.

Hope that helps.

-C