What are the benefits of seperating network firewall and VPN services?

Separating network firewall and VPN functions can be a significant benefit to an organization in two scenarios.

The first scenario is a large IT security team with groups separated by function -- for example, one group manages firewalls, and another manages the VPN. By separating the network firewall and VPN functions, each group can enjoy autonomy in its administrative functions.

The second scenario is an environment in which performance requirements for the network firewall and VPN system are such that running both on the same device isn't feasible. In this instance, the separation of these functions adds significant performance advantages.