Imagine if you could travel back in time seven years, and tell Axel Clauberg, then newly employed at Deutsche Telekom, where the just-launched Terastream project would be in September 2018. You might find him raising a glass of his favorite Westphalian Altbier to a breakthrough on the IP and optical side, while cursing the hold-ups in other network areas.
Conceived as a way to radically simplify the design of telecom networks, Terastream was part of a rallying cry for the industry when it was first announced in 2012, just as concepts like network functions virtualization (NFV) entered the public consciousness for the first time. That cry has echoed throughout the intervening period, as transformation has turned out to be much tougher than Clauberg and others had envisaged. "The industry is clearly not where it was supposed to be," he says. "Maybe I was too optimistic in 2012," he tells Light Reading. (See DT Unveils New Network Vision.)
But if Terastream and other initiatives are still not in full flow, there have been some encouraging signs of progress this year. In Croatia, where the operator's networks effectively act as the Terastream testbed, Deutsche Telekom AG (NYSE: DT) launched its first commercial services based on the Terastream architecture in March. Local subsidiary T-Hrvatski Telekom now claims to offer a gigabit-speed broadband service to customers in Zagreb, Split and Karlovac using Terastream technology. If all goes smoothly, Deutsche Telekom's other national operating companies will be expected to follow. (See Eurobites: Proximus Snaps Up Managed Security Specialist.)
In his position as the vice president of IP and optical architecture (among other things), Clauberg is not prepared to comment specifically on Terastream in Croatia or plans elsewhere. For him, the real measure of success is to see Terastream's individual elements taken into operation across Deutsche Telekom's footprint in central and eastern Europe. Some of these elements have already been widely deployed, he indicates. On others, it appears that Deutsche Telekom still has a way to go.
Just what are these various elements of Terastream? Thus far, the initiative has been widely interpreted as a cloud-based broadband service. It has also been conflated with Deutsche Telekom's pan-net program, an attempt to produce and manage services at a limited number of regional data centers each addressing multiple markets, and not through separate facilities for each country. Neither representation is strictly accurate, although cloud-based services are an important aspect of Terastream, and there is overlap with pan-net. (See DT's Pan-Net Still at Start of the Marathon.)
Clauberg says Terastream essentially has three parts, of which pan-net largely relates to one. The starting point in 2011 was to come up with an IP (Internet Protocol) and optical network architecture that stripped out much of the existing complexity. "We observed exponential traffic growth on the IP side and the existing vendor solutions didn't actually meet requirements," says the former Cisco man. "The traditional way of building networks is becoming too expensive."(See DT's Clauberg: TIP, TeraStream & NFV.)
Deutsche Telekom's answer was to go minimalist. Imagining what they would do if they had to build a network entirely from scratch, and without any of the usual legacy constraints, the Terastream technicians started converging the IP and optical layers during a Croatian pilot that started in September 2012. "We are using coherent interfaces in the routers and our optical network is just a combination of amplifiers and passive splitters," says Clauberg. Interoperability and an end to vendor lock-in were key Terastream requirements. (See DT: Telcos Must Escape Vendor Prison.)
The move was not initially popular with Deutsche Telekom's suppliers. The optical industry at that time was, in Clauberg's assessment, "a good example of a closed ecosystem." Companies that had made substantial investments in the latest technologies suddenly found one of Europe's biggest operators rejecting what they had to offer. When it came to 100-gigabit optical systems, for instance, the only option for telcos was to use a single vendor's technology at both ends of a link. "We didn't want to have that," says Clauberg. "We had to convince the industry to create a forward error correction standard that was acceptable to everyone."
The first big success came in 2013 when Deutsche Telekom was able to demonstrate long-haul interoperability between Cisco Systems Inc. (Nasdaq: CSCO) and Alcatel-Lucent (now subsumed into Nokia Corp. (NYSE: NOK)) during its Croatian trials. Huawei Technologies Co. Ltd. and Juniper Networks Inc. (NYSE: JNPR), the German telco's other optical vendors, soon joined them. The shift now appears to have had a drastic impact on the entire IP and optical industry. "When you look at form factors, there are [component] companies like Acacia producing standard pluggables you can insert in any router and have interoperability in the long haul," says Clauberg.
The Terastream shake-up has also led Deutsche Telekom towards open source code, in some areas. While the architecture is based on IPv6, the most recent version of the IP communications standard, Deutsche Telekom must also continue to support the older IPv4 technology (IPv5 never came to fruition). In partnership with the Internet Engineering Task Force (IETF) it has worked on a standard called Lightweight 4over6, which can be used in conjunction with a so-called address family translation router (AFTR) to get around this particular IP problem. Clauberg describes the technology as the "first high-volume network function we built in our data centers," and says open source has fed into it.
Industry groups like the Facebook-led Telecom Infra Project, which named Clauberg its chairman in August 2017, are today running with the same objectives that first prompted the development of Terastream. Such momentum has broken up the proprietary optical ecosystem, says Clauberg, and is now stimulating the design of new 400-gigabit optical systems. As for Deutsche Telekom, this IP and optical integration "is in widespread use across the footprint," he says. That is clearly something to celebrate.
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