ContributionsMost RecentMost LikesSolutionsRe: Need firmware update for SBG6580 modem - current firmware kills VOIP I have a same issue. Got SBG6580 with 3.2.1 firmware where as Charter and Comcast already upgraded their customers withSBG6580-3.5.8.1-GA-01-477-NOSH. That is the latest firmware that has many new features and bug fixes. Cox MUST upgrade us too!