Juniper's SDN Will Build Service Chains
Juniper finally spoke up with a software-defined networking (SDN) plan on Tuesday, describing a network where chains of functions can be run in software, each element growing or shrinking as necessary.
That description, presented during a keynote at Juniper's Global Partner Conference, put a practical spin in SDN. "We think it's what SDN is really all about," said Bob Muglia, Juniper's executive vice president of software.
The announcement was important because Juniper seemed left behind as competitors, including Cisco, loudly proclaimed their SDN plans. Juniper does have the QFabric data-center fabric, which exhibits key properties of SDN, but the company hadn't put forth a total SDN strategy until now -- and QFabric's popularity has been questionable, by most analysts' estimation.
Juniper decided its approach would be to distill the scattered SDN conversation in to one architectural construct, Muglia said.
Like other companies, Juniper said SDN is all about services, but the "service chain" description created a concrete image of what to expect from the technology.
Juniper's chain gang
"Service chain" was Muglia's phrase for functions that get linked together and have to work together. This already happens in the network; it's just that it happens physically. A router might attach to a firewall and an intrusion detection platform, for instance. Each of the three has performance limits, and each has to be configured when anything changes. Under SDN, the alternative would be for those elements (possibly even the router, someday) to run as virtual machines on servers, allowing each element's capacity to get dialed up or down as needed. They would be linked together by a control plane that's at least partially centralized. "That is all controlled by the SDN controller. It is all set up by the SDN service chain, and all of those things are connected logically together," Muglia said. That's where December's acquisition of Contrail comes in. Muglia didn't give any new details, but he said Contrail will be the basis of the logically centralized control plane that Juniper will offer. Contrail's work involved the creation of a control plane that's distributed around the network, in elements using the BGP and XMPP protocols to exchange information about the network. Moving to the center
Now, getting to that point of SDN service chains will take some legwork. Before doing that, operators will want to centralize many of their network functions -- other than the forwarding plane of switches and routers, which still would operate in a distributed fashion. "We propose that you use cloud techniques to build all of these systems -- the management plane, control plane, services plane... so now we move to a world where these capabilities, these network planes, can run on x86 servers in a data center, and they run as virtual machines just like any application would be run," Muglia said. The management plane should be centralized first, to do away with manual configuration that's done today through text-based, command-line interfaces. In fact, configuration is often cited as an area where SDN could really help, by saving time and eliminating human error; Muglia, like many others, emphasized that point. After that, services -- things such as security appliances -- should go to the cloud, with elements such as security appliances being replaced by virtual machines, he said. Juniper believes that none of this means hardware becomes commoditized, of course. Nor does it mean that routers immediately make the jump to being virtual machines. "There's a whole set of other functions, in particular the forwarding functions and some attributes of those services, that can be performed by ASICs that are designed and optimized to forward packets and forward flows," he said. Licensing sucks
As perhaps a preparatory step toward SDN, Juniper also announced the Juniper Software Advantage licensing program on Tuesday. It's a program to let customers license a certain capacity of software -- 10Gbit/s of throughput, for instance -- and let them split it among multiple systems. By contrast, today's licensing is tied to particular boxes and isn't transferable to other boxes. The idea was to mimic the licensing practices of enterprise software, Muglia said. "Licensing in networking is so messed up that we had an opportunity to completely reboot it," especially with SDN on the horizon, he said. — Craig Matsumoto, Managing Editor, Light Reading