Vectra S.A., one of the leading cable operators in Poland, has built a nationwide fiber backbone using ONS 15454 Multiservice Optical Transport Platform (MSTP).
Vectra’s new network is a nationwide ring, connecting nearly 30 cities around Poland, including Warsaw, Katowice, Wroclaw, Poznan, Radom, Bydgoszcz, Torun, Gdynia and more. Initially, the network operates multiple wavelenghts at 10 Gbps.

Klonex, a Cisco Premier Certified Partner in Poland, designed and implemented the DWDM network for Vectra.
http://newsroom.cisco.com/press-release-content?type=webcontent&articleId=1216657