Software-defined what? Look at our glorious ASICs says Cisco

Borg betting big that some networks can't be white-boxed any time soon

White boxes

Cisco's taking up arms against a sea of white-box vendors, touting US$150 million worth of silicon in the form of an ASIC.

What's interesting, however, is that the pitch – in this blog post – isn't about what's coming this year or next.

The slab of silicon, which the Borg is calling the “Unified Access Dataplane” (UADP), landed in 2013.

Cisco's Ivor Diedricks – senior product manager for Catalyst switching in Cisco's Enterprise Networking Group – writes that the “home-grown ASIC” is fundamental to integrating wired and wireless traffic.

In a nod to the principles of software-defined networking (SDN), Diedricks says that with more devices out there consuming more bandwidth, “the dataplane / forwarding plane and at times, control plane traffic needs to be distributed”.

By integrating the dataplane into the ASIC, he reckons, the ASIC supports switches that can forward wireless traffic at 60 Gbps, something the post claims can't be achieved with a centralised controller.

Other features of the ASIC include wire-speed DTLS (datagram transport layer security) encryption and decryption, and – in a poke at the white-box-plus-software market – all traffic fragmentation and reassembly happen in hardware.

CAPWAP – a protocol for controlling and provisioning of the wireless access network – tunnels are terminated on the chip, and it also handles QoS at the port, access point, radio interface, SSID and client level. The chip also makes the wireless traffic fully visible to Netflow and Wireshark.

So what?

All of which is nice, but it invites a question: “so what?”

The chip isn't just another piece of Moore's law in sand and plastic: Cisco is singing its song to the front rows, not the cheap seats down the back.

“The largest wireless networks in the world trust Cisco”, the post tellingly reminds us – but most networks don't need the very peaks of performance.

Diedricks poses questions that network owners should ask themselves, and these clearly define the market Cisco's after:

  • Can the wireless traffic be delivered at wire-speed onto the wired side of the network?
  • Can I treat the wireless traffic in the same way as the wired traffic – i.e. apply the same levels of QoS, policing, shaping, rate limiting, dropping, etc. at multiple levels in the hierarchy?
  • Is the wireless traffic terminated in the same ASIC as the wired?
  • Does wired and wireless traffic traverse the same Dataplane path internal to the product?

These questions clearly describe the scale that Cisco sees as its sweet spot: networks too large to be white-boxed, but without the vast internal engineering resources of a hyperscale data centre to make all that virtualised network SDN stuff work.

Even then, the outside world can't be ignored: Cisco has added OpenFlow 1.3 support to the UADP. That will let UADP-based products get new features that aren't baked into the silicon.

So far, if you ask Cisco, its strategy of deploying high-power ASICs against the white-box threat is a success. Outgoing CEO John Chambers said as much in June.

The Borg, it seems, is keeping a handy supply of stakes an hammers, just in case the “dead” market needs another whack. ®

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