The context of what a perimeter is changing as organizational boundaries become dispersed across the internet. In other words, as more and more businesses adopt the concept of a truly mobile workforce. How a perimeter is defined and how it is protected changes. Thus… this is null argument. While you still need some type of perimeter protection, granted it isn't an island of protection anymore, but rather a fluid barrier (the usage of Application Layer firewalls and SSL/TLS comes to mind). You also still need Defense in Depth (DID). In fact, neo-perimeter protection is a must for true DID.

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