A cable communications network provides an alternative communications path between a user equipment device and a data network to a cellular path for a communications session with a desired level of Quality of Service. A cable modem termination system, coupled to a wireless core network, e.g., a 5G core network, interacts with the wireless core network to attempt to establish a PDU session for a UE with a desired QoS level. The core sends a QoS service request message to the CMTS including a requested level of QoS, an IP address and port number for the session. The CMTS and cable modem, corresponding to the UE, negotiate and decide if the request desired QoS level can be supported over the cable between the CMTS and the cable mode for the session.