With the development of cloud computing technology, compared with traditional servers that run applications directly, virtual machines run on servers, and applications run on virtual machines are becoming more and more common.
In this case, the network is often the most critical performance bottleneck, especially how high-speed network traffic between different virtual machines can be effectively exchanged.
To solve the problem of large traffic switching, there are basically two simple ideas: one is Softswitch, that is, put it in the server for software implementation. A typical representative is that there are various virtual exchange solutions, for example, openvswitch.
The other is that the traffic is transparent to the server and all is thrown to the physical switches outside the server. This is mainly the IEEE edge virtual bridging (EVB) standard currently discussed, including 802.1qbg and 802.1qbh.
Softswitch is easier to implement.
Vmm creates a virtual network card for each Vm and corresponds to a port of the software switch. The physical Nic of the server is also connected to an interface of the software switch. All switches are completed by the software switch.
The advantage of this scheme is that the forwarding performance between virtual machines is very good, and various control functions can be easily implemented in software switches. However, the problem is that the CPU resources of the server OS are much consumed, and performance bottlenecks may easily occur during external exchange.
The EVB standard tries to import all the traffic from the VM to an external switch for decision-making. The advantage is that the performance and complex control features of the external hardware switch can be used. The disadvantage is that one-to-one bandwidth efficiency is low and the driver support on the server needs to be modified.
Refer:
[1] http://www.cisco.com/c/en/us/products/collateral/switches/nexus-1000v-switch-vmware-vsphere/whitepaper_c11-620065.html
[2] http://wikibon.org/wiki/v/Edge_Virtual_Bridging
Virtual Machine Network Access Technology
