Conference Calls - Linking up multiple calls

[japan6]

Well the manual for your phone says that it can hold up to a total of 5 people on the conference call

[TechSE]

This feature is network service dependent along with technology limitations.
At max one person can connect to five people on conference.
More than five is not possible due air timeslot bandwidth and fair distribution issues.
Further relation to it is call conference codecs that user phone is having.