\n| \n Last date of support<\/p>\n<\/td>\n | \n 31 January 2032<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Cisco names the Desk Phone 9841<\/strong> as successor to the 7841 and the Desk Phone 9851<\/strong> as successor to the 7861. Organisations that need more line keys can add the 9800 Key Expansion Module.<\/p>\nWhat changes for Extension Mobility?<\/h3>\nThe 9800 series runs Cisco’s new PhoneOS firmware instead of the classic SIP firmware. Extension Mobility remains fully supported on CUCM (12.5(1) and later), and since PhoneOS 4.0 the Extension Mobility menu sits at the top level of the phone’s Settings, so it stays reachable even when settings access is restricted. From CUCM 15 SU3 onwards, PhoneOS firmware for the 9800 series is included in the CUCM installation image.<\/p>\n Your existing device profiles, user associations and Extension Mobility service subscriptions carry over. What does change is the phone model in your templates, button layouts and any phone-specific services, so plan a test round before you replace phones in bulk.<\/p>\n |