We have 3 digits extensions on freePBX. When I make a call from Software phone to any extensions everything works fine, but all other users must wait about 5 sec or press # to finish dial. All users are connected to grandstream 4004. I saw an option early dial and enable it. Dialing is now faster but I can dial only 2 digits and get a message “Your call cannot be completed… Please check the number and dial again”. Where to find problem solution? In freePBX or grandstream?
Do your phones have any kind of “Dial Plan” or “Digit Map” string where you can enter dialing patterns? Did you enter a rule there for three digit numbers? Also, bear in mind that if you shorten the delay for three digit numbers, it may prevent you from dialing seven or ten digit calls (in the USA/Canada/etc., anyway) unless you take special care about how you number your extensions (for example, if they are all in the range 100-119 them there should not be a conflict, assuming you add a proper rule such as 1xS0 or 1xT0 or whatever is the correct syntax for your phone).
The delay is there by default because the phone doesn’t know if you’re calling a three digit number, or have only dialed the first three digits of a longer number.