Cable and DSL are both Broadband (compared to dial-up, which is narrowband) so the router doesn't matter. DSL connects to your phone line while Cable goes through your...well..cable hookup. I think that the jack you're refering to is Ethernet, which simply connects the router to your cable/dsl modem, and also then connects your modem to your pc. Any broadband router will be fine, just buy from a good brand like Linksys, Netgear, or D-Link.