Cyan's stackable optical rack for data centre interconnent
"The drivers for these [data centre] guys every day of the week is lowest cost-per-gigabit"
Joe Cumello
The amount of traffic moved between data centres can be huge. According to ACG Research, certain cloud-based applications shared between data centres can require between 40 to 500 terabits of capacity. This could be to link adjacent data centre buildings to appear as one large logical one, or connect data centres across a metro, 20 km to 200 km apart. For data centres separated across greater distances, traditional long-haul links are typically sufficient.
Cyan says it developed the N-series platform following conversations conducted with internet content providers over the last two years. "We realised that the white box movement would make its way into the data centre interconnect space," says Cumello.
White box servers and white box switches, manufactured by original design manufacturers (ODMs), are already being used in the data centre due to their lower cost. Cyan is using a similar approach for its N-Series, using commercial-off-the-shelf hardware and open software.
"The drivers for these [data centre] guys every day of the week is lowest cost-per-gigabit," says Cumello.
N-Series platform
Cyan's N-Series N11 is a 1-rack-unit (1RU) box that has a total capacity of 800 Gigabit-per-second (Gbps). The 1RU shelf comprises two units, each using two client-side 100Gbps QSFP28s and a line-side interface that supports 100 Gbps coherent transmission using PM-QPSK, or 200 Gbps coherent using PM-16QAM. The transmission capacity can be traded with reach: using 100 Gbps, optical transmission up to 2,000 km is possible, while capacity can be doubled using 200 Gbps lightpaths for links up to 600 km. Cyan is using Clariphy's CL20010 coherent transceiver/ framer chip. Stacking 42 of the 1RUs within a chassis results in an overall capacity - client side and line side - of 33.6 terabit.
There is a whole ecosystem of companies competing to drive better capacity and scale
The N-Series N11 uses a custom line-side design but Cyan says that by adopting commercial-off-the-shelf design, it will benefit from the pluggable line-side optical module roadmap. The roadmap includes 200 Gbps and 400 Gbps coherent MSA modules, pluggable CFP2 and CFP4 analogue coherent optics, and the CFP2 digital coherent optics that also integrates the DSP-ASIC.
"There is a whole ecosystem of companies competing to drive better capacity and scale," says Cumello. "By using commercial-off-the-shelf technology, we are going to get to better scale, better density, better energy efficiency and better capacity."
To support these various options, Cyan has designed the chassis to support 1RU shelves with several front plate options including a single full-width unit, two half-width ones as used for the N11, or four quarter-width units.
Open software
For software, the N-series platform uses a Linux networking operating system. Using Linux enables third-party applications to run on the N-series, and enables IT staff to use open source tools they already know. "The data centre guys use Linux and know how to run servers and switches so we have provided that kind of software through Cyan's Linux," says Cumello. Cyan has also developed its own networking applications for configuration management, protocol handling and statistics management that run on the Linux operating system.
The open software architecture of the N-Series. Also shown are the two units that make up a rack. Source: Cyan.
"We have essentially disaggregated the software from the hardware," says Cumello. Should a data centre operator chooses a future, cheaper white box interconnect product, he says, Cyan's applications and Linux networking operating system will still run on that platform.
The N-series will be available for customer trials in the second quarter and will be available commercially from the third quarter of 2015.
Colt's network transformation
Colt's technology and architecture specialist, Mirko Voltolini, talks to Gazettabyte about how the service provider has transformed its network from one based on custom platforms to an open, modular design.
It was obvious to Colt that something had to change. Its network architecture based on proprietary platforms running custom software was not sustainable; the highly customised network was cumbersome, resistant to change and expensive to run. The network also required a platform to be replaced - or at least a new platform added alongside an existing one - every five to seven years.
Mirko Voltolini
"The cost of this approach is enormous," says Mirko Voltolini, vice president technology and architecture at Colt Technology Services. "Not just in money but the time it takes to roll out a new platform."
Instead, the service provider has sought a modular approach to network design using standardised platforms that are separated from each other. That way, a new platform with a better feature set or improved economics can be slotted in without impacted the other platforms. Colt calls its resulting network a modular multi-service platform (MSP).
The MSP now delivers the majority of Colt's data networking and all-IP services. These includes Carrier Ethernet point-to-point, hub-and-spoke and private networks services, as well as internet access, IP VPNs and VoIP IP-based services.
The vendors chosen for the MSP include Cyan with its Z-Series packet-optical transport system (P-OTS) and Blue Planet software-defined networking (SDN) platform and Accedian Networks' customer premise equipment (CPE). Cyan's Z-Series does not support IP, so Colt uses Juniper Networks' and Alcatel-Lucent's IP edge platforms. Colt also has a legacy 20-year-old SDH network but despite using a P-OTS platform, it has decided to leave the SDH platform alone, with the modular MSP running alongside it.
Colt chose its vendors based on certain design goals. "The key was openness," says Voltolini. "We didn't want to have a closed system." It was Cyan's management system, the Blue Planet platform, that led Colt to choose Cyan.
Associated with Blue Planet is an ecosystem that allows the management software to control other vendors' platforms. Cyan uses 'element adapters' that mediate between its SDN interface software and the proprietary interfaces of its vendor partners. Cyan says that its Z-Series P-OTS appears as a third-party piece of equipment to its Blue Planet software in the same way as the other vendors' equipment are; a view confirmed by Colt. "Because of its openness, we have been able to integrate other vendors to use the same management system as if they were Cyan components," says Voltolini.
"Cyan was probably the best option available and we decided to go with it," says Voltolini. The company was looking at what was available two years ago and Voltolini points out that the market has evolved significantly since then. "In the end, if you want to move ahead, you need to make decisions," he says. "We are quite happy with what we have picked and we continue to improve it."
Colt says that as well as SDN, network functions virtualisation (NFV) is also important. "With the same modular platform we have created a virtual component which is a layer-3 CPE," says Voltolini. The company is issuing a request-for-information (RFI) regarding other CPE functions like firewalls, load-balancers and other networking components.
Benefits and lessons learned
Adopting the MSP has speeded up Colt's service delivery. Before the modular network, it would take between 30 and 45 days for Colt to fulfil a customer's request for a three-month-long Ethernet link upgrade, from 100 Megabit to 200 Megabit. Now, such a request can be fulfilled in seconds. "We didn't need any more layer-3 CPE and we can upgrade remotely the bandwidth," says Voltolini.
Colt also estimates that it will halve its operational costs once the new network is fully deployed; the network went live in November 2013 and has not been deployed in all locations. The operational expense improvement and the greater service flexibility both benefit Colt's bottom line, says Voltolini.
A key lesson learned from the network transformation is the importance of leading staff through change rather than any technological issues. "The technology has been a challenge but in the end, with the suppliers, you can design anything you want if you have the right level of collaboration," says Voltolini. "But when you completely transform the way you deliver services, you are touching everything that is part of the engine of the company."
Colt cites aspects such as engineering solutions, service delivery, service operations, systems and processes, and the sales process. "You need to lead the transition is such a way that everybody is going to follow you," says Voltolini.
Colt encountered obstacles created because of the staff's natural resistance to change. "Certain things took longer," says Voltolini. "We had to overcome obstacles that weren't really obstacles, just people's fear of change."
The art of virtualised network function placement
Cyan is delivering its Blue Planet NFV orchestrator software that will make use of enhancements being made to OpenStack developed by Red Hat in close collaboration with Telefónica.
Gazettabyte asked Nirav Modi, director of software innovations at Cyan, about the work.
Q: The concept of deterministic placement of virtualised network functions. Why is this important?
NM: We are attempting to solve a fundamental technology challenge required to make NFV successful for carriers. Telefónica has been doing a lot of internal trials and its own NFV R&D and has found that the placement of virtualised network functions greatly affects their performance.
We are working with Telefónica and Red Hat to solve this problem, to ensures virtualised network functions perform consistently and at their peak from one instance to another. This is particularly important for composite or clustered virtualised network function architectures, where the placement of various components can affect performance and availability.
Also, you need to ensure that the virtualised network functions are located where the most suitable compute, storage or networking resources are located. Other important performance metrics that need to be considered include latency and bandwidth availability into the cloud environment.
What is involved in enabling deterministic virtualised network functions, and what is the impact on Cyan's orchestration platform?
Deterministic placement requires an orchestration platform, such as Cyan’s Blue Planet, to be aware of the resources available at various NFV points of presence (PoPs) and to map operator-provided placement policies, such as performance and high-availability requirements, into placement decisions. In other words, which servers should be used and which PoP should host the virtualised network function.
For the operator, interested in application service-level agreements (SLAs) and performance, Cyan’s orchestration platform provides the intelligence to translate those policies into a placement architecture.
Does this Telefonica work also require Cyan's Z-Series packet-optical transport system (P-OTS)?
NFV is all about taking network functions currently deployed on purpose-built, vertically-integrated hardware platforms, and deploying them on industry-standard commercial off-the-shelf (COTS) servers, possibly in a virtualised environment running OpenStack, for example.
In such an set-up, Cyan’s Blue Planet orchestration platform is responsible for the deployment of the virtualised network functions into the NFV infrastructure or telco cloud. Cyan’s orchestration software is always deployed on COTS servers. There is no dependency on using Cyan’s P-OTS to use the Blue Planet software-defined networking (SDN) and NFV software.
The Z-Series platform can be used in the metro and wide area network to enable a scalable and programmable network. And this can supplement the virtual network functions deployed in the cloud to replace existing hardware-based solutions, but the Z-Series is not involved in this joint-effort with Telefónica and Red Hat.