[OF-DPA] A simple L2 switch RYU app for OF-DPA

I found there is a official OF-DPA web site that contains some good information about RYU and OF-DPA as follows:
http://ofdpa.com/

I also put my simple L2 switch RYU app for OF-DPA which I had done an example in the last year and cannot guarantee there is no error/bug. But, it is still worth referencing. Enjoy.
Here it is:
https://github.com/teyenliu/OF-DPA

[TTP] What is Table Type Patterns?

As we know ( if you have to deal with the multiple flow tables of OF 1.1+ ), the multiple flow tables provide the scaling capability but increasing the complex of usage. For software switch either running on hypervisor or on operation system, it can use memory to map to the implementation of such table design. But for hardware switch based on ASIC to handle packet process pipline, the forwarding pipeline and the definition of flow table is specified and fixed. That will generate a big issue: How come application running on SDN controller knows how to deal with these specified limitation. Recently I noticed "TTP", stands for Table Type Patterns, to allow for an OpenFlow controller and OpenFlow switch to agree on a set of functionality to help manage the increased diversity made possible with OpenFlow versions 1.1+. I think that is very useful for the case: OF-DPA.

https://www.sdncentral.com/education/openflow-table-type-patterns-opendaylight-next-release-colin-dixon/2014/08/
This article mentions these capabilities have made OpenFlow a much more interesting tool in two major ways:

1. Better for developers. Simply put, the new features allow developers to do more interesting things: handle IPv6 traffic, provide better multipathing, and separate logical concerns into different tables. Of course, this is all limited to software switches if hardware doesn’t expose these features via OpenFlow, and it can’t do that if OpenFlow provides poor abstractions for hardware.

2. Better mapping onto hardware. The original model of OpenFlow (a single, very flexible table) was actually a poor fit for real network hardware. The new model allows for an OpenFlow table pipeline that can much more closely match the pipelines in real networking ASICs. This allows hardware to both expose more of its capabilities and expose them to controllers (and thus developers) in a way they can efficiently take advantage of.


https://github.com/OpenNetworkingFoundation/TTP_Repository/blob/master/TTP-FAQ.md
This FAQ document give us more information in details:

TTPs will be particularly helpful in simplifying the coding of advanced OpenFlow datapath control (where many flow tables or optional functions are needed). Because TTPs describe the expected controller/switch messaging unambiguously, they will also improve interoperability.

TTPs will also be helpful in testing or benchmarking contexts where participants want advance notice to ensure conformance or optimize performance. Such participants expect precise descriptions of what messages will be used during testing or benchmarking.

To legitimately claim support for a TTP, a switch must implement all non-optional functionality described by the TTP. As mentioned above, a TTP may describe some functionality that is optional.


PS: OpenDaylight has support TTP in Helium version
https://wiki.opendaylight.org/view/Table_Type_Patterns:Helium_Release_Notes

[OF-DPA] Glance at the source code of OF-DPA on GitHub

I just quickly glance at the code of OF-DPA and draw a skeleton of it. Actually it is only about the integration Indigo with OF-DPA API ( blue color part ), and lock in with SDK and switch device. There is no OF-DPA/SDK source code ( red color part ). As the diagram described, the OEM/ODM Development Package has the full source code distributed under Broadcom SLA.