motorola mb8611 docsis 3.1 multi-gig cable modem | pairs with any wifi router | approved for comcast xfinity gigabit, cox gigablast, spectrum, and more | 2.5 gbps ethernet port motorola the motorola mb8611 ultra-fast docsis 3.1 cable modem supports true gigabit plus speed tiers with a 2.5 gb ethernet port. approved for comcast xfinity, cox, and charter spectrum services only, this cable modem is backward compatible with 32x8 docsis 3.0.