A gateway in SONA is a special compute node, which plays role as a connection point to external networks. It performs NAT and PAT for outbound traffics and also exchanges routes with external routers with BGP or OSPF. Scalable gateway provides load balancing and high availability by allowing multiple redundant gateways to the system.
Features
- Provides load balancing balance of outbound traffics among multiple gateways
- Provides fail-over for a gateway failure
- Provides dynamic add or remove of gateway nodes
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SONA is composed of multiple ONOS applications, and Scalable Gateway and vRouter are takes in charge of the North-South connectivity.
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- GNODE is composed of two software switches controlled by SONA and vRouter
- br-int which is controlled by SONA, OpenstackRouting module specifically, performs NAT and PAT of for N-S packets
- br-router which is controlled by vRouter makes the GNODE as a legacy router and it performs forwarding packets to right port
Detailed Architecture
- Scalable GW manages the information of GNODEs
- OpenstackRouting requests the information of GNODEs
- Scalable GW provides the load-balancing policy to OpenstackRouting
Scalable GW handles GNODE fail-over and scale-out
Upstream Traffic Load Balancing
Gateway Node Fail-Over
Dynamic Gateway Node Scale-Out