About

I'm Chris Wendt. The work that runs through everything I do is a single question that has worn many disguises: how do we make communication technology that people can trust?

For thirty years that question has taken me through audio DSP and 3D sound, early video streaming, voice over IP, and now the cryptographic trust frameworks that authenticate calls in North America. The technologies have changed; the question hasn't.

Where I am

I'm currently VP of Systems Engineering at Somos, Inc. — the nonprofit telecommunications trust and number administration company that operates several of the central trust mechanisms underpinning North American voice and messaging. I lead our Systems and Platform Engineering teams and serve as principal architect of the company's Trust Framework strategy.

This site — appliedbits — is my personal notebook, kept separately from that work. The views I publish here are mine alone.

What I work on in standards

I'm the primary author of STIR/SHAKEN, the cryptographic call authentication standard now deployed across North American telephone networks (RFC 9796 et al.). I co-chair ATIS IPNNI and the US STI-GA Technical Committee. I serve as editor for ITU-T documents in SG2 and SG11. I sit on the SIP Forum board and contribute to the CFCA Trusted Traffic Working Group, the GSMA RCS group, and the IETF working groups where this work mostly lives — STIR, vcon, and ACME.

The work I'm most invested in right now is VESPER — a draft I'm authoring that extends STIR's caller identity model with cryptographic binding to internet domain names. It's the bridge from the trust framework we built for traditional voice into the trust framework we'll need for the next decade of communications: messaging, RCS, and the agentic AI calls that are coming whether we're ready or not.

Where the technical work meets policy

Trust frameworks for telecommunications don't live in any single venue. The protocols are designed in IETF working groups; they get adopted into industry practice through ATIS and SIP Forum; they get harmonized internationally through ITU-T study groups; and they get operationalized through FCC orders, tariffs, and cross-border policy coordination. The work I do sits at the intersection of these — the technical specifications that get written in one venue have to make sense in all the others, and getting that right requires moving fluently between protocol design, industry consensus, and regulatory framing.

I'm not a lawyer and I don't practice policy. What I do is author the technical specifications that policy ends up referencing — the RFCs that the FCC cites, the ITU-T documents that international regulators harmonize against, the ATIS standards that carriers implement under tariff. The bridge between “how this protocol works cryptographically” and “how this protocol gets deployed under regulation” is the actual work, and most of my output over the past decade has been some form of that bridge.

The longer arc

I started in audio. The first commercial work I shipped was DSP code for 3D positional audio in games and VR — figuring out how to fool the ear, in real time, with the limited compute of late-90s consumer hardware. From there I moved to early video streaming, then to voice over IP just as it was becoming a serious replacement for circuit- switched telephony.

For most of the 2010s I was at Comcast, where I led the architecture of the carrier-grade VoIP infrastructure underneath Xfinity Voice and innovated on the unified-communications and business-communications platforms built on top of it. The STIR/SHAKEN work began there. When I moved to Somos in 2022, I built the systems engineering team to transform the platform engineering strategy and to keep innovating and iterating on the standards for telephone number trust and the broader trust framework.

The thread connecting all of it: real-time communications systems have always been about making humans trust the connection enough to use it. The DSP work was about acoustic plausibility. The streaming work was about reliability under network jitter. The VoIP work was about call quality at scale. The trust framework work is about cryptographic identity. Different layers of the same problem.

Why the notebook

Most of my professional output gets published in IETF drafts, ATIS documents, ITU-T contributions, and conference talks. Those have audiences but they're narrow ones — protocol designers and standards bodies. The ideas inside them are usually broader than the document formats allow.

This notebook is where I write longer-form, less-constrained, about what I'm actually thinking. Some entries are observations from standards work. Some are arguments for or against directions the industry could take. Some are just the working-out — me thinking in public, the way an engineer might keep a notebook on the bench. The lineage of that practice runs from Edison to Bell Labs to IBM Watson Research to every working engineer who's ever kept a record of what they were figuring out.

I'm new to this kind of writing. The first entries will probably show that. I'm publishing anyway, because the alternative — waiting to be a polished writer before publishing anything — is the alternative that never publishes anything.

How to reach me

Email is best: chris@appliedbits.com. I'm on LinkedIn and GitHub. The notebook has an RSS feed.