DX Series have no video when it calling with the other phone ？

[laview.lwchen]

i used DX80 call other phone （such as 7942 or cti port），There have no video on DX80 screen。I want to create conference with three endpoint（ two DX80 and one cti port），but no video on DX80。how should i do？

[laview.lwchen]

Oh，I get it，The Muti conference License is expired in my CCM，so that There have no Video on DX80。