Do We Really Need PTP? A Comparison of Clocking & Synchronization in RTP, RAVENNA/AES67 & ST2110, AVB and IPMX 

The presentation starts by introducing the differences between asynchronous, plesiochronous, isochronous and fully synchronous operations. It then looks at particular synchronization requirements of professional media transport systems. After setting the scene, the individual synchronization methods provided by various common transport technologies are explained and compared against the requirements. The presentation looks at the inherent asynchronous operation of RTP as specified in RFC 3550. It then explains why RAVENNA, AES67 & SMPTE ST 2110 required a more advanced synchronization method, why PTP had been chosen and how synchronization is actually achieved.  Another popular transport mechanism for certain fields of application is AVB; it turns out that AVB also utilizes a variant of PTP but differs from the before mentioned standards in the way it actually implements synchronization. Finally, the presentation looks on how IPMX implements synchronization, in particular as it claims to be SMPTE ST 2110-compliant but can also work without PTP. In the conclusion, the benefits and drawbacks of each method are highlighted and the question if we really need PTP will be answered (or not?).