Real-time communication over packet networks has always been a nightmare. Mature technologies like SDH/SONET handle this type of traffic easily because transmission delays are negligible and fixed. Packet networks however are far more unpredictable, and delays tend to be long. This is no issue for most modern applications like internet browsing, broadcasting of video or file transfer. But for industrial networks, real-time data communication is critical. For that reason, many industrial users opt for SDH/SONET technology in the WAN, still today.
As soon as the IEEE started to issue the first MPLS-TP drafts, OTN Systems recognized that the successor of SDH/SONET was born. This packed based standard was set to become a viable alternative to SDH/SONET, and more. The paradox was solved! In the meantime, MPLS- TP is coming on strong as other vendors jump on the bandwagon and end-users start recognizing the value it.