What is a VPN Concentrator?

Answer 1

VPN Concentratorsare the ideal device when you require a single device to handle a large number of incoming VPN tunnels. VPN concentrators also allow for greater security from one of two architectures: SSL VPN or IPSec VPN. Some concentrators only offer support of one protocol or the other, whereas Cisco and other vendors advertise the ability to utilize either with their concentrators. The traditional tunnel for VPNs relies on IPSec, which resides at the network layer of the OSI model. At this level, a client is considered a virtual member of the connected network and can pretty much access the network as if locally connected. Therein lies a positive aspect of IPSec: Apps run without any awareness that the client is coming from outside the network. The drawback is that additional security controls have to be configured to reduce risks. For a client to access the IPSec VPN, it must have the client-side software configured. While this adds security, it provides additional cost to implement and leads to additional time and energy spent by tech support. This is what leads many toward an SSL solution. SSL is already built in to the capabilities of pretty much all computers through Web Browsers. Thus, there is no additional work to install and configure the client side. In addition, rather than residing at the network layer, allowing access to all aspects of a network, SSL lets administrators allow access a bit more precisely toward applications that are Web-enabled. In addition, administrators can establish a finer level of control over uses with SSL VPN connections. On the negative angle, however, being that you can only utilize SSL VPNs through a Web browser, only Web-based applications will work. With a little bit of work, you can Web-enable additional applications, but this adds to the configuration time and may make SSL an unattractive solution for some.

Answer 2

It's a thing that does stuff. Cool stuff.