Map physical network resources to the constructed virtual network. Mapping identifies which virtual network each packet transmitted or received by an OpenFlow switch belongs to, as well as which interface in the OpenFlow switch transmits or receives that packet. There are two mapping methods. When a packet is received from the OFS, port mapping is first searched for the corresponding mapping definition, then VLAN mapping is searched, and the packet is mapped to the relevant vBridge according to the first matching mapping.
Port mapping | Maps physical network resources to an interface of vBridge using Switch ID, Port ID and VLAN ID of the incoming L2 frame. Untagged frame mapping is also supported. |
VLAN mapping | Maps physical network resources to a vBridge using VLAN ID of the incoming L2 frame.Maps physical resources of a particular switch to a vBridge using switch ID and VLAN ID of the incoming L2 frame. |
MAC mapping | Maps physical resources to an interface of vBridge using MAC address of the incoming L2 frame(The initial contribution does not include this method). |
VTN can learn the terminal information from a terminal that is connected to a switch which is mapped to VTN. Further, it is possible to refer that terminal information on the VTN.
- Learning terminal information VTN learns the information of a terminal that belongs to VTN. It will store the MAC address and VLAN ID of the terminal in relation to the port of the switch.
- Aging of terminal information Terminal information, learned by the VTN, will be maintained until the packets from terminal keep flowing in VTN. If the terminal gets disconnected from the VTN, then the aging timer will start clicking and the terminal information will be maintained till timeout.
The following figure shows an example of mapping. An interface of BR1 is mapped to port GBE0/1 of OFS1 using port mapping. Packets received from GBE0/1 of OFS1 are regarded as those from the corresponding interface of BR1. BR2 is mapped to VLAN 200 using VLAN mapping. Packets with VLAN tag 200 received from any ports of any OFSs are regarded as those from an interface of BR2.
