SDN WAN BGP
Implementing BGP gateways with SDN has significant performance benefits and cost savings potential for service provider and ISP backbone or metro networks.
SDN BGP gateway drivers and challenges
BGP is the de facto protocol for routing between domains in the internet—it’s the protocol of choice between ISPs but also the core routing protocol within large service provider networks. BGP’s performance has a long track record but it is a cumbersome and challenging protocol to use in service provider networks that are looking for more dynamic policy-aware tuning.
Network operators are rightfully frustrated with border routers because they have no control over where individual traffic goes. They’re stuck with static weights assigned to the traffic without the ability to fine tune and implement traffic engineering with policy configurations at border edges.
This can make the traffic hard to manage dynamically and impossible to adjust for individual customer requirements.
What network operators need is policy-driven, dynamic configurations that the BGP protocol uses to move traffic with flexibility, performance and scale.
Flexibility and scale with SDN BGP gateways
The solution is SDN BGP gateways.
These SDN BGP gateways must have the capacity and speed to implement some of the largest BGP routers that connect the core fabric of the internet. Up until now, single table OpenFlow or limited multi-table implementations of OpenFlow data planes have meant reliable, full scale orchestration of networks has not been achieved. Corsa’s WAN and metro-edge SDN data planes are deploying and proving that SDN BGP gateways can be operated at scale all the while being fully interoperable with the external internet.
These SDN BGP networks can range from an autonomous systems (AS) domain operated by a smaller ISP to the entire transport network operated by a large carrier.
Making it real
An international SDN-only IP transit network of three autonomous systems managed as SDN domains has been implemented with Corsa, ESnet and REANNZ. The partners took the approach of building and testing an internet-scale SDN solution that not only embodies the SDN vision of separation of control and data, but enables seamless integration of SDN networks with the internet.
This first implementation passed through three AS domains, namely Energy Sciences Network (ESnet) at Berkeley, REANNZ at Wellington, and Google research deployment at Victoria University, Wellington (NZ). ESnet’s node used the Corsa DP6420 640Gbps data plane as the OpenFlow hardware packet forwarder, controlled by the open-source VANDERVECKEN SDN controller stack (based on RouteFlow and Quagga). The Research and Education network infrastructure from CENIC/PacificWave and AARNet provided the data transport functions to connect these AS’s together.
This SDN BGP connection between two national-scale network providers shows that full internet-scale routing over an international network of mixed SDN and non-SDN autonomous systems is possible when the right SDN hardware is used.
Corsa’s SDN BGP gateway solution features
Corsa has successfully designed massive FIB table capacity into a highly efficient, high performance SDN data plane which in combination with the separate control plane implements a SDN BGP router. This allows network orchestration to dynamically adjust or adapt forwarding for any number of purposes such as for SLA compliance, real-time load balancing, peering arrangements or time of day.
Corsa’s SDN data planes support over a million flows and fast flow table refresh rates to scale for any network application. At the core of the data plane is a completely flexible OpenFlow datapath that can be programmed via open interfaces. Using open source controllers such as ONOS, SDN-IP, Vandervecken, RYU or Open Daylight, the SDN BGP gateway is a solution that comes together very simply and economically. For those wanting more to do with network architecture and less DIY, Corsa also supplies a BGP routing stack to speed time to deployment.
Overall SDN provides an unprecedented level of control and visibility for networks, enhancing user experience and operational capabilities.
With SDN BGP gateways, network operators get the operational agility and programmability of the SDN architecture to achieve policy-aware border routing with fine-grained traffic control.