The idea is to meter this as the L3 routers levels. The point is to allow operators to configure IP ranges and to assign a label to them. For example we will be able to set two labels; one for the internal traffic, and the other one for the external traffic. Each label will measure the traffic for a specific set of ip range. Then, bandwidth measurement will be send for each label to the Oslo notification system and could be collected by Ceilometer.
The metering of the bandwidth can be realized by set up some IPtables rules on each l3 namespaces.
1. Add a global rule for the metering on the FORWARD chain of each router.
2. Add rules to the metering chain for each traffic that we want to measure.
3. These rules will point to a specific chain used to collect the traffic (packets, bytes). This chain will represent the metering label.
4. Add an agent to get the bandwidth information from IPtables chain. This agent will populate bandwidth usage informations as delta with the Oslo notifications mechanism.
Iptables Chain Model
The implementation of this extension follow the next plan:
1. Add metering chain to IPtables at the router creation
2. L3 Agent modifications
3. Database model and API modifications
4. Add new command to CLI