Virtual switching at NICs has several noticeable advantages. First, it leads to better resource utilization at the hosts.
The host CPUs are dedicated for use by the VM workloads so that the computationally intensive tasks can obtain a larger share of the CPU cycles.
There are also performance advantages.
The packet processors at NICs are optimized for packet processing, leading to better packet-switching performance than the host CPUs.
Another advantage is the isolation of computing and packet switching. The natural isolation of VM computing and virtual-switch packet processing significantly reduces the context-switching overhead and complexity of buffer management. Finally, the separate domain (NIC) for packet switching also improves the data center networks’ security and reliability. Such decoupled virtual switching is a salient technology Figure 5.
A virtual switch on an intelligent NIC. The natural isolation of VMs and their packet switching in such an architecture is highly beneficial.
NIC bonding. Also known as link aggregation, this software-oriented approach groups multiple physical network links and provides the network bandwidth as an aggregate logic to the VMs.