Network-as-a-service (NaaS) is a cloud service model in which customer request the networking infrastructure who doesn't want to build their application. NaaS services offer Datacenter connectivity, Wide area network connectivity, demand Bandwidth and other applications. NaaS provides virtualized network infrastructure, and customers can deploy custom routing protocols.

The NaaS service provider manages all the infrastructures; customers don't need to worry about that. It is also cost-effective as it provides a virtual environment to the customer, and their no physical cost involve for hardware and maintenance. NaaS is also based on a pay-per-use model.

Mobile Network-as-a-service: Service providers also provide Mobile NaaS, which is more flexible and efficient to control on mobile devices. 

Benefits of Network-as-a-service (NaaS)

1. Scalability: Cloud services are easily scalable compared to traditional models and can be easily scaled as per the user's requirements.
2. Accessibility: Based on how the cloud network is configured, the application is accessible from anywhere at any time without a VPN and independent of the platform or device used for access.
3. No Maintenance: The infrastructure maintenance depends upon the service provider, so the customer does not need to worry after the updates.  
4. Security: NaaS providers make it possible by providing networking and security services such as firewalls. This offers customers a tight integration between network and network security.
5. Cost Saving: The customer doesn't need to buy, configure and manage the hardware infrastructure; its cloud provider maintains and provides services to the client.

Disadvantages of Network-as-a-service (NaaS)

1. Compatibility: The NaaS service provider may not be compatible with the legacy system, such as old hardware, on-premises applications, etc.
2. Vendor Lock-in: Once customers take services from one service provider, switching to another vendor will be risky. Also, if the vendor's infrastructure fails or the vendor increases the cost, the enterprise may suffer from it.
3. Legacy Data Centre: For an organization still running applications and processes on their in-the-house data centre, not on the cloud, it will be difficult to move large applications and processes in NaaS.