The operator says the OpenStack community will have to overcome six key challenges before the technology becomes acceptable.

Iain Morris, International Editor

October 14, 2015

5 Min Read
BT Threatens to Ditch OpenStack

DUSSELDORF -- SDN & Openflow World Congress -- BT is threatening to abandon OpenStack in favor of a proprietary technology during its rollout of virtual enterprise services unless vendors backing the standard can overcome six potential technology showstoppers.

Such a move by the UK fixed-line incumbent could be a major setback for OpenStack, an open standard that is being touted as one of the key technologies underpinning NFV.

BT Group plc (NYSE: BT; London: BTA)'s concern relates to the use of OpenStack with virtual enterprise CPEs, whereby servers are distributed around the edge of the network and on customer premises.

Peter Willis, BT's chief researcher for data networks, acknowledges that OpenStack has major attractions as set of open source tools, with backing from some of the world's biggest IT companies, but says the technology still holds a number of risks for an operator rolling out virtual enterprise CPEs.

Unless the OpenStack community can address a number of serious challenges, BT will look to use an alternative technology.

Those challenges relate to the connection of virtual network functions (VNFs), service chain modification, scalability, so-called "start-up storms," the security of OpenStack over the Internet and backwards compatibility.

"If these six issues are not addressed we will not use OpenStack for virtual enterprise," he told attendees here in Dusseldorf. "There are proprietary solutions out there we could use and we will use them in lieu of OpenStack being available."

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Willis revealed that some of the most important OpenStack stakeholders -- including HP Inc. (NYSE: HPQ), Red Hat Inc. (NYSE: RHT), Canonical, Mirantis Inc. and Intel Corp. (Nasdaq: INTC) -- have agreed there are problems but have not yet reached a consensus on how to address them.

Although BT could opt for a proprietary technology in the short term and introduce OpenStack at a later stage, this will become more difficult as services are rolled out.

"It's a strategic migration issue," says Willis. "It's easy to start off greenfield because we've not deployed any large numbers of virtual enterprise CPEs but in two or three years there will be more legacy."

Next page: The six challenges

The six challenges
Providing more detail on the six challenges he outlined, Willis says the first issue is connecting VNFs to the infrastructure. OpenStack does this in a sequential manner, with the sequence serially numbered in the VNF, but the difficulty comes when trying to verify that the LAN has been connected to the correct LAN port, the WAN has been connected to the correct WAN port and so on. "If we get this wrong for a firewall function it could be the end of a CIO's career," says Willis.

OpenStack also appears to come up short in the area of service chain modification, whereby new services are inserted into the mix. "Let's say we deliver a router and a firewall to the customer and they're connected together and then the customer asks for a WAN accelerator," explains Willis. "There is no way to do that in OpenStack -- you have to disconnect the interface and reconnect."

BT has tested the disconnection and reconnection of interfaces with a range of VNFs from different vendors and had mixed results. In the worst-case scenario, VNFs have locked up entirely and the operator has had to remove them and start from scratch.

One answer to the second challenge might be deleting the service chain and starting afresh, according to Willis, but this could have repercussions for customer service.

Lack of scalability is a further problem. The BT executive reckons a single OpenStack controller can be expected to manage about 500 computing nodes. "In our virtual enterprise CPE scenario we're talking of the order of 100,000 CPEs to manage and so that scalability figure is not very good."

The "start-up storms" to which he refers can happen when, say, a fiber connection is broken and then subsequently fixed. "Imagine we have a controller with 100,000 nodes and all these distributed agents try to reconnect at the same time," says Willis. "They're all using encryption and that's slow and computationally intensive and the only way to get the network back is to phone up customers and tell them to turn their nodes off and on again one at a time -- that is not going to be very pleasant with 100,000 customers."

Securing OpenStack over the Internet is an additional headache for Willis. During his own tests, he took a computing node and put this on the end of a DSL line connected to the Internet, but to make it work he had to open more than 500 pinholes in his firewall to the controller. "That's like a highway -- it's a serious problem," he says. "We definitely need to consider how we secure OpenStack over the Internet because we will be having virtual enterprise CPEs on the end of Internet connections."

Finally, there is a need for backwards compatibility between the versions of OpenStack, says Willis, who rules out any possibility that BT will be able to run the whole network on the same version.

"It's not feasible for managing a carrier service because I've got thousands of customers and each customer may have a different planned engineering works," he says. "We have to have backwards compatibility and be able to run multiple different versions on the computing node from a single controller."

— Iain Morris, Circle me on Google+ Follow me on TwitterVisit my LinkedIn profile, News Editor, Light Reading

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About the Author(s)

Iain Morris

International Editor, Light Reading

Iain Morris joined Light Reading as News Editor at the start of 2015 -- and we mean, right at the start. His friends and family were still singing Auld Lang Syne as Iain started sourcing New Year's Eve UK mobile network congestion statistics. Prior to boosting Light Reading's UK-based editorial team numbers (he is based in London, south of the river), Iain was a successful freelance writer and editor who had been covering the telecoms sector for the past 15 years. His work has appeared in publications including The Economist (classy!) and The Observer, besides a variety of trade and business journals. He was previously the lead telecoms analyst for the Economist Intelligence Unit, and before that worked as a features editor at Telecommunications magazine. Iain started out in telecoms as an editor at consulting and market-research company Analysys (now Analysys Mason).

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