AVN-GMCOS Grandmaster clock is a master clock for AoIP audio network with built-in GPS receiver. IEEE1588-2008 PTPv2 (precision time protocol) is used for synchronization of all nodes in the network. AVN-GMCOS supports (RAVENNA), Media (AES67) and AES-R16-2016 (SMPTE-ST 2059-2 & AES67 compatible) profiles, and also has the ability to save custom profiles. AVN-GMCOS is based on an Oven Controlled Oscillator (OCXO) and has an accuracy of 0.1 ppm or max +- 1 second / 115 days.