Do I need zaptel or ZTdummy to use FreePBX?

Im using Asterisk with an external SIP / ISDN gateway, but in the FreePBX installation says I need Zaptel or ZTdummy.
Do I really need to install zaptel to use FreePBX?
Joao Pereira

Unless you have some actual Zaptel hardware, which in your case it doesn’t seem you do, you should install ZTdummy. Asterisk requires one or the other for timing purposes.