Because USB 1.1 is a 12 megabit connection, when users connect other devices, they quickly consume the 12 megabits. This causes the connection to slow. Other devices also sometimes conflict with the USB-connected modem, creating instability.
Ethernet, on the other hand, is the industry small network standard. A NIC (Network Interface Card) is required. If you don't have one, they usually run $10-$20. Because this is 100 megabits full-duplex, the connection can't be fully saturated by the modem.
If you do decide that USB is the best solution for you, drivers can be found here: Drivers
*This FAQ is based on user knowledge from a volunteer core of BroadbandReports' members. This FAQ in no way constitutes official information from Comcast or any of its affiliates.
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