Network as a Service (NaaS)
Network as a Service (NaaS) Discussion
Network as a Service (NaaS) is sometimes listed as a separate Cloud provider along with Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). This factors out networking, firewalls, related security, etc. from IaaS as is shown in the figure below.
NaaS can include flexible and extended Virtual Private Network (VPN), bandwidth on demand, custom routing, multicast protocols, security firewall, intrustions detection and prevention, Wide Area Network (WAN), content monitoring and filtering, and antivirus. There is no standard specification as to what is included in NaaS. Implementations vary.
NaaS Variation
Some implementations of Network as a Service (NaaS) are referred to as Telco as a Service (TaaS).

Related Articles
More on the general topic: Cloud Computing Categories