The process is very complicated from Huawei MSTP equipment( http://www.thunder-link.com ) OSN 3500 configuration to management. You'll in confront of all kind of technical problems. Here we have three STM64 channels, one of our services is STM4*4 (2,5 Gbit/s). At first we wanted to redund the whole channel STM64 via SCNMP - one STM64 is working and other two are the protection channels - but it is not optimal solution. The question is the following: can we protect with SCNMP only these four STM4? so that in each channel we had free 7,5 Gbit/s for traffic?