[asterisk-users] Option 't' on DIal

[Nhadie]

Hi,

I encountered something i can't understand. I've setup 2 extensions.

[100]
type=friend
host=dynamic
nat=yes
secret=100

[101]
type=friend
host=dynamic
nat=yes
secret=101

and on extensions.conf

exten => _1XX,1,Dial(SIP/${EXTEN}|30|t)
exten => _1XX,n,Hangup

This dial plan is ok, audio connects both ways.
but when i had a typo error, i forgot the 't' option, only one way audio 
when i call, 't' option is used to transfer call how come it affected 
the audio?

thank you in advanced

regards
nhadie