As Ethernet turns 40, some seek to take it to the cloud
As Ethernet marks its 40th birthday this week, some of those celebrating will also be looking ahead to yet another use for the nearly ubiquitous technology: the cloud.
On Thursday at the Ethernet Innovation Summit, which will include a commemoration of Ethernet's invention on May 22, 1973, a group of cloud vendors and users are launching the CloudEthernet Forum. It will be announced on the second day of the event in Mountain View, California, with the backing of Alcatel Lucent, Juniper Networks, Tata Communications, Citrix, and other founding members.
Ethernet, originally a LAN, increasingly is also used for WANs (wide-area networks) operated by enterprises and service providers. The CloudEthernet Forum aims to make Ethernet better suited to large-scale cloud services that may operate across many data centers.
Enterprise and service-provider clouds have grown to the point where they may have millions of virtual machines and, in the case of public clouds, thousands of customers. At that level, Ethernet can start to show some limitations, said James Walker, president of the CloudEthernet Forum.
For one thing, Ethernet generates a lot of traffic for purposes such as record-keeping and discovering resources on the network, he said. With the huge numbers of tenants and virtual machines that can be active on a cloud service, that administrative traffic can multiply until it starts to crowd out the packets that the network was built to carry. For service providers, that represents traffic that doesn't generate revenue, said Walker, who is also vice president of managed network services at Tata. The CloudEthernet Forum may look for ways to reduce that administrative traffic in cloud networks.
Another limitation that Ethernet runs into on clouds is a cap on the number of virtual LANs that can be set up on one network. The limit is about 4,000 VLANs, which might be adequate within one enterprise but come up short in a public cloud network, Walker said. If there are hundreds of thousands of customers hosted in a service provider's data center, and each wants separate VLANs for its production, database, Web and other operations, Ethernet's VLAN limit will fall short.
The CloudEthernet Forum also wants to bring more coherence to standards for storage on Ethernet networks. There are too many competing standards, and different implementations of those standards, for some cloud service providers to keep up, Walker said. Some Ethernet storage standards, such as Fibre Channel Over Ethernet, might need adjustments to suit the needs of cloud networks, Walker said.
The forum's founders have not yet targeted any specific standards for modification, he said. Through a technical committee, the CloudEthernet Forum will define problems and work to solve them either by certifying its own standards or asking another standards body, such as the IEEE or MEF, to modify its standards, Walker said.
The group will be an activity of the Metro Ethernet Forum, which works on specifications for wide-area Ethernet, but will be an independent body, according to Walker. It will share some back-end resources with MEF, whose board will sign off on the specifications adopted by the CloudEthernet Forum. However, MEF's membership won't shape the new group's direction, said Nan Chen, president of MEF.
There are some notable absences in the forum's membership as it launches. Most prominently, Cisco Systems isn't a member. But the 11 founding members include several high-profile names, including Huawei Technologies, Verizon Communications and cloud service provider Equinix. Organizers have talked with Cisco and other potential members, who may yet join, Walker said. Membership is open to anyone for an annual fee of $15,000. MEF members can join for $10,000, because some administrative costs are shared.
The fact that builders of massive cloud infrastructures are now looking to Ethernet as a backbone shows how far the technology has come from being a 2.94M bps LAN in 1973, Walker and Chen said.
"It's great that the original idea of Ethernet is something that is so flexible, adaptable and extensible that it's been able to remain current and relevant," Walker said.
The trail was blazed for cloud Ethernet 10 to 15 years ago when the technology was first adapted to WANs and the Metro Ethernet Forum was launched, Chen said. "We really bridged the telechasm, if you will, from LAN to WAN," he said.