This paper presents a quantitative analysis of the Quality of Service (QoS) offered by Virtual Private Networks (VPNs) based on the suite of protocols IPSec (IP Security) in a Computer Supported Collaborative Learning environment. Testing was done with routers and network nodes which held a communication channel through a videoconference. The objective is to analyze whether the IPSec VPNs configure with AES are good enough to transmit real time multimedia traffic while protecting the information. Our results show that under stress traffic conditions the IPSec VPN could not offer an adequate QoS to the videoconference in terms of network latency, and that is why new alternative technologies need to be implemented in order to mitigate the degradation. The IPSec VPN technology is evaluated under the latency, jitter and packet loss parameters, which are the basic ones that determine the QoS in a point to point link.