[asterisk-users] Little help with Conference

[Ruben Zamora]

These is my scenario.

Asterisk 1.4.16
Zaptel    1.4.8

Grandstream BT200
Grandstream GXP2020
Grandstream GXP2000

For some reason the end user ask to configurate son direct access  like 
*01,*02,*03 thru *78.

After they began to use these direct access, I cant place a 3 way 
CONFERENCE.

I remove the direct access, but i dont know if one of them block the 
CONFERNCE.

Do you know if i can make reverse for these???

Thanks

Ruben