Carriers Step Away from ASICs

　　SAN JOSE, Calif. — A group of telecom carriers will demonstrate at Mobile World Congress progress moving their networks off proprietary systems and on to open source software. The Open Networking Foundation (ONF) will show its latest code based on the P4 programming language running on systems using chips from Barefoot Networks, Cavium and Mellanox.

　　The demo marks a significant change for ONF that initially based its work on its OpenFlow protocol. The group shifted last year to P4, an open source project launched by Barefoot, after vendors hit limits with OpenFlow.

　　The group’s goal now is to evangelize support for P4 among networking leaders. Broadcom, the dominant vendor of merchant switch chips, is said to be showing interest in P4.

　　So far Cisco, the leading provider of ASIC-based networking systems is not showing interest P4. ONF aims to cultivate an ecosystem of so-called white-box networking OEMs such as Quanta and Delta using its open source software.

　　It’s still early days for ONF’s open source code for the style of edge-cloud networks carriers want to deploy. The so-called edge clouds aim to be more open, lower cost alternatives to the central offices carriers use today based largely on systems running a complex mix of ASICs and proprietary protocols.

　　With the shift to P4, ONF has code for access networks in field trials but software for mobile core nets is still in the lab with trials a year or two away.

　　“Were at an interesting inflection point,” said Timon Sloane, vice president of marketing and ecosystems for ONF, calling the latest demos a second-generation of software-defined networks (SDNs).

　　The latest demo is “a glimpse of the edge cloud of the future,” blending in work on SDN standards such as ETSI’s Network Functions Virtualization, he said.

　　“We learned a ton from OpenFlow, but it has limitations, so the community strategically shifted to P4 and the P4 runtime to solve problems in a more comprehensive way,” said Sloane, adding ONF is no longer actively developing the protocol.

　　OpenFlow has been used by Google, China Mobile and others to access the data forwarding pipeline of networking ASICs. However, it cannot access all their functions and, unlike P4, it doesn’t enable programming that pipeline.

　　“OpenFlow turned out to be non-deterministic with nuanced differences between systems so tiny adjustments were needed for different ASICs. That hampered the ability to bring on multiple suppliers. P4 is more deterministic and allows a complete definition of the forwarding pipeline,” he said.

　　The P4 code is available as open source and was first demoed in September. The current demo is the first using systems from multiple vendors. Later this year, ONF hopes to host another demo with at least two more silicon vendors participating.

　　Startup Barefoot created its chips in tandem with the P4 open source project. Cavium and Mellanox modified firmware of their existing chips to support P4 in the demo.

　　To date, Broadcom has focused on making the programming interfaces for its switches more accessible; last week it made its table APIs open source. Sloane characterized the move as a step in the right direction, opening up its forwarding plane but not yet making it fully reconfigurable.