Start reading 2014.Nach something in the world of IP telephony and the here of other helpful tips, true everything Okay. The configuration of the Grandstream then ran like clockwork. The Fritz box 7390 with current firmware made no difficulties. Until 02.16.2015 the world was fine until we even faster Internet wg. professional reasons needed. IP telephony with the new hybrid router TCom defacto a mess, despite correct settings according Tcom. Meanwhile, tell me colleagues that these problems only with the new TCom routers, especially the brand new hybrid router, all built by Huawei, occur. Meanwhile TCom has admitted that apparently lay the circus on the firmware of the router, you promised me an update by the end of the end of March, which I do not think so. Currently the Grandstream is useless in the corner. So with TCom routers I would not buy at the time of this good se IP phone. Clear purchase decision for this, but with the Fritz box !!!