Close extension for trunk

how can i close an estension for trunk. (an extension can communicate all other extension but can not call from any trunk )

Any chance you can rephrase your question? I don’t understand what you are trying to do.

suppose that i have 5 trunks (t1,t2,t3,t4,t5).i am using PSTN for t1 ;voip for t2; GSM GW for t3; Sat Phone for t4; Mobile Phone for t5

how can i block some extension can not call anywhere using t4 and t5

It is all in the context, learn how the calls flow and you will have a easier time with this.
the “simple way” is to download and install a Freepbx module called custom contexts.
The fast and nasty way is to hack a custom context out of the outbound context and add in as a new context.

search for custom contexts