This is a monthly fee for the Audiocodes AL/SU-AGW/M36 product, specifically covering the support and licensing for one analog port on the Audiocodes Mediant 3600 Gateway.
This subscription ensures continued functionality, technical support, and access to software updates for the analog interface of your Audiocodes gateway solution.
AL/SU-AGW/M36 - Audiocodes : Mnth fee for a 1 analog