Thoughts on code development, access technologies, and telecommunication networks from developers within ADTRAN’s R&D organization.
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Written by: Peter Kerr & Marc KimpePublished: 8 June 2016
We are ADTRAN. We are a tech company founded in 1986. We went public in 1994. A tech IPO before it became in fashion. A tech company that weathered multiple transitions in technology and economic cycles. A tech company whose motto is “the only constant is change.”
ADTRAN’s creation coincided with the Bell System divestiture mandated in 1982. AT&T was broken up into 7 Regional Bell Operating Companies (RBOC) providing local phone service while AT&T retained long distance service. The RBOCs would be free to pick equipment suppliers rather than relying on an AT&T subsidiary. ADTRAN’s founders made a successful bet that the Bell Companies would need help building their carrier to carrier network. The technology available at the time was a mere 1.544Mbps symmetric called T1. ADTRAN started manufacturing full rate and sub-rate T1 transceiver and receivers.
Building on the limited T1 technology of the time, ADTRAN transitioned into an innovator helping define and drive HDSL, HDSL2, HDSL4, SHDSL and 2 BASE-TL. The nature of HDSLx symmetric transmission fit well with business customers, so ADTRAN expanded its carrier business with an enterprise business providing switches, routers and enterprise network equipment.
At the same time, technologies like ADSL and VDSL were coming of age, targeted primarily at residential services. Those technologies traded rate for reach. The shorter the copper loop, the greater the data rate. The newer technologies provided higher upstream bandwidth making them suitable for residential and business deployments. The days of HDSLx were numbered. ADTRAN started its second transition to a system and multi-technology Access vendor.
ADTRAN’s software development also transitioned. On the HDSLx products, embedded and FPGA software would implement layer 1 DSP processing – equalizers, pre-coders, framers, etc. The name of the game was efficient programming, as memory and CPU resources were scarce. When the company transitioned to a system vendor and added enterprise switching and routing, layer 2 and 3 stacks were added along with the necessary management. Delivering applications such as IPTV, VoIP and data service – either residential or business class became the focus. Most of this was programmed in C or C++ while network management evolved into Java. ADTRAN acquired the fixed wireline assets of Nokia Siemens Networks expanding into Europe and the international market. The NSN engineers brought their software heritage and best practices. In parallel, we grew an ADTRAN India development center. Along the way, we introduced Linux as an operating system.
Today, the telecommunications landscape includes a multitude of companies of different size, make-up and history delivering triple play (voice/data/video) over copper, fiber and coax. Data rates have increased substantially in the access. Fiber through Active Ethernet, GPON and EPON technology offers 1 or 2 Gigabit rates while NGPON2/XGS-PON /10G-EPON reach 10Gbps rates. Good Ol’ Copper did not sit still; techniques such as vectoring and bonding enabled greater rate culminating in the G.fast standard delivering 1 Gbps over copper. ADTRAN helped define and is deploying a number of those technologies.
Telecommunications companies are going through another transition: the move to SDN (Software Defined Networking) and NFV (Network Function Virtualization). The move can loosely be attributed to cost reduction initiatives amongst the Facebooks and Googles of this world: on the hardware side, the advent of white boxes and on the software side, the advent of open source software. Internet companies needed vast data centers to run their businesses. None wanted to be locked-in with vendors. Their engineers open sourced hardware designs allowing low-cost manufacturers to supply generic hardware and started open sourcing important pieces of software. After all, the business of many Internet companies is not software, it is advertising or ecommerce – software and hardware are a means to an end. Open source increased in quality and gained momentum. The era of open source software arrived.
The telecommunications world took notice. SDN offers the promise of removing siloed vendor management and application software in favor of an open unified software platform build around an open source SDN controller. NFV offers the promise of cost reduction through high volume commodity servers and faster software deployment in data centers.
Over the last few years ADTRAN transitioned to SDN and NFV. Step one of the NFV transition was to identify, isolate and package modules of value, allowing them to be independently shared and deployed. Step two was running the software stack on commodity CPUs rather than a network processor. Our embedded heritage proved serendipitous and our engineers are very happy with the small footprint our entire router image achieved. Step one of the SDN transition was the creation of “platform teams” whose job was to create a platform that enables other engineers to build scalable, reliable cloud products. In that role, documenting and testing in real time became crucial as it allowed them to quickly deliver the functions needed to the other engineering teams. The team selected microservices as the basis of the architecture. They embraced Test Driven Development and implemented a Continuous Integration pipeline outputting tested Docker images. A User Experience (UX) team brought focus on usability and challenged us to be more user friendly rather than algorithmically savvy.
Merging SDN and NFV together brought us to CORD – Central Office Re-architected as a Data Center: providing access leveraging SDN and NFV. CORD realizes and enables an open access architecture. Open means the platform can be used by 3rd party equipment manufacturers. Open means that we are consuming and contributing open source works. Open means partnership and sharing with our customers and the wider community. A number of our Proof of Concept CORD pods are making their way around the world in customer labs.
In the spirit of openness, we take the next step in creating this blog. Over the coming months and years our R&D staff will be sharing tales of our successes and failures, the technologies we are now using with commentary on them, architectural patterns, development practices, our experiences with the DevOps movement and Continuous Integration and Delivery and lessons learned. We will share this insight so that others might also benefit. ADTRAN has always been a software company. Over 30 years our focus has changed from the embedded systems of TDM channel banks to cloud architectures for orchestrating millions of access devices. This blog starts the next evolution in our software practices: Open Access.
We are ADTRAN. Welcome.
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