Volker Hilt has a passion for computer science — bringing this energy to problems in computer networking, cloud computing technologies and distributed multimedia systems.

Initially, Volker studied commercial information technologies (Diplom Wirtschaftsinformatik) at the University of Mannheim in Germany.  After he realized his true calling was in computer science, he stayed at Mannheim to complete a computer science Ph.D., which he received in 2001. During the last year of his graduate studies, Volker spent a summer at Bell Labs in New Jersey. Impressed by the expertise of the researchers he met and the openness to discuss problems and new ideas, he applied for a job at Bell Labs and joined after completing his degree.

Solving SIP Overload

Volker’s career began as an MTS in the Networking research domain where he worked on Internet multimedia services and the Session Initiation Protocol (SIP) — the foundation of many Internet telephony systems today. SIP servers deployed in early commercial services at that time could experience congestion collapse under very high call volumes and enter a regime in which they could not successfully process calls. Volker and colleagues identified the problem, its root causes, and showed that SIP overload can spread through a SIP network and shut down a telephony service provider.

“Developing a solution and getting this solution ready for deployment is extremely satisfying.”

They developed a solution for SIP overload control that preserves SIP server functionality even under extreme loads and brought this solution to the Internet Engineering Task Force (IETF) standards body. “This type of work is what gets me excited about Bell Labs,” Volker says. “Working together with other researchers to identify a problem that matters, developing a solution and getting this solution ready for deployment is extremely satisfying.” Apart from his accomplishments in SIP, Volker has made technical contributions in the areas of cloud computing, content distribution networks, peer-to-peer applications, and distributed multimedia systems.

Across the Atlantic and Back

In 2008, Volker became a department head in the Service Infrastructure research domain at Bell Labs, and later served as acting leader for the domain. After ten years working in the US, Volker returned to his home country in 2012 where he now leads a team in the IP Platforms program at Bell Labs in Stuttgart, Germany.