Can get a splitter with RJ45 ports?, Using Streamyx

Hello,
I bought a new modem that came with a Y cable that has to be used to connect to the DSL and telephone line of the splitter... unfortunately it needs RJ45 ports (like DSL), and the splitter only has RJ11 ports. Do you know if I can buy a splitter with those RJ45 ports or if I can get it from TMNet?

Thanks!