At Cable-Tec Expo, Tektronix is unveiling Sentry ABR (adaptive bit rate), the latest member of its Sentry line of digital content monitors. It's intended to enable video service providers to ensure the quality of their ABR-based TV Everywhere and (OTT) services.Sentry ABR is designed to validate all assets, bitrate profiles and manifest files based on a parallel HTTP fragment fetching engine. It supports up to 250 top manifests, and manifest files and fragments can be fetched from any place on the network - such as origin servers and content distribution network (CDN) caching servers - to simulate a subscriber's request for content.