What Is a Virtual Router?

Why Do We Need Virtual Routers?

As enterprise services become more diversified, more and more enterprises deploy virtual private clouds (VPCs) on private or public clouds to cloudify and virtualize enterprise networks and IT infrastructure, thereby reducing network costs and implementing fast service rollout. In addition, application providers gradually provide enterprises with mission-critical applications (such as office and Salesforce) in Software as a Service (SaaS) mode on clouds. According to related statistics, 85% of enterprises will migrate their applications onto the cloud in the future.

As cloud-based services develop, applications and traffic surge. Traditional enterprise WANs cannot satisfy the requirements of enterprise infrastructure and service cloudification, and face the following challenges:

• Branches need to access cloud applications through the headquarters or data center, causing a long delay and performance bottlenecks.
• Enterprise service cloudification poses high requirements on WAN bandwidth, leading to a year-by-year increase of private line costs.
• Enterprises cannot implement consistent security and management policies on public cloud networks and enterprise internal networks.
• The traditional enterprise WAN status cannot be detected, making management and O&M difficult.

Virtual routers address these challenges and cope with trends of network device cloudification and virtualization . Virtual routers are deployed in Network Functions Virtualization (NFV) mode and can convert traditional functions that rely on hardware network devices into software that can run on existing standard hardware devices. Virtual routers save hardware costs because no dedicated hardware platform is required. Virtual routers decouple IP routing functions from specific hardware and allow the functions to be flexibly deployed on the network. Virtual routers can be deployed in the enterprise headquarters, Point of Presence (PoP), and cloud environments to extend the enterprise network to the cloud and implement consistent security and management policies on the cloud and enterprise network. In addition, virtual routers can access WANs through hybrid links, and provide application-based intelligent traffic steering for optimizing enterprises' cloud access paths and improving experience of enterprise users in accessing cloud services.

How Does a Virtual Router Work?

A virtual router works similarly to a traditional router. It runs routing protocol instances, has its own dedicated I/O ports, buffer, address space, routing table, and network management software, and connects to devices to forward data packets between networks. With the development of networks, the basic architecture of virtual routers is evolving.

Huawei AR1000V is deployed in VNF mode. Figure 1-2 shows the system architecture of Huawei AR1000V, which consists of the following key components:

• Physical hardware and host operating system: A universal x86 hardware platform provides hardware resources such as the CPU, memory, NIC, and storage medium, and basic operating system services.
• Hypervisor: It supports mainstream virtualization platforms, such as KVM, FusionSphere, and VMware. As the intermediate software layer between physical servers and VM instances, Hypervisor manages VMs, allows multiple VM instances to share hardware resources, and isolates and protects VMs.
• vSwitch/PCI-passthrough: It enables information exchange between VM instances and between VM instances and external networks.
• VM instance: It uses the Linux operating system, has independent vCPU, memory, storage, and vNIC resources, and carries VNF instances, and provides routing, switching, security, and VPN functions.

Typical Applications of Virtual Routers

In the SD-WAN Solution, the AR1000V can function as an interworking gateway (IWG) to connect to a PoP gateway. It can also be deployed on the cloud as a cloud gateway to implement one-hop cloud access for enterprises.