In France, a router is rented about 3€ ($4) per month by the majors ISPs (the renting cost is not shown idependently by two of the three major ISPs. Orange expl

In France, a router is rented about 3€ ($4) per month by the majors ISPs (the renting cost is not shown idependently by two of the three major ISPs. Orange explicitly shows its renting cost on bills. That's cheap for a broadband router-modem-WiFi AC-2 channel voice box. They are all customized broadcom boards. Using another router is technically very hard for anything other than the IP data : Orange for example uses ATM QoS with specific DHCP WAN string initialization options, specific SIP channel setup and even worse for IPTV VLAN. The SIP channel sold is almost impossible to use with a third party SIP client device. Let's add they won't lift a finger in case of an issue if you use your own router. To sum it up : not worth the trouble !