Asterisk Channel Pickup

At times, when a user picks up the phone to make an outbound call they wont receive a dial tone. Instead, Asterisk has picked an open Zap channel that actually has an inbound call on it that Asterisk has not answered yet, therefore thinking the channel is open. With a high call volume this occurs frequently. Is there any way to correct this?

This is called glare. I don’t think it is completely avoidable, but you need to make sure you have an earth start, PABX line, not a loop start, domestic, line. You also need to make sure that your outgoing hunt sequence is opposite from the incoming hunt sequence.

I had a similar issues with all analog digium boards.
I’m in Italy, i don’t know which kind of line i have.

I’m using fxs_ks signalling for fxo ports and fxo_ks for fxs ports, loadzone and defaultzone=it and opermode italy.

Sometimes, users that lift the headphone can’t hear anything or a busytones.
Sometimes also the fxo port is blocked and if someone call from outside to my landline can hear the phone ringing (like the pbx is not linked) or some other times the busytone.
Some other times this is what happen

Sometimes i can resolve unplugging the rj11 connector or rebooting the system.

It happened with several boards (tdm410, tdm2400), several lines and several machine (from p4 1600 256mb ram to athlon dualcore 4gbram)

Could it be a big error on my configuration?
Do I have a glare issues too?

This is my chan_dahdi.conf

;General options -
usecallerid = yes
hidecallerid = no

busydetect = yes
threewaycalling = no
transfer = yes
echocancel = yes
echocancelwhenbridged = yes

rxgain = 0.0
txgain = 0.0

;FXS Modules
group = 1
echocancel = no
signalling = fxo_ks
context = Internal
channel => 2-4

;FXO Modules
group = 2
echocancel = yes
signalling = fxs_ks
context = Incoming1
channel => 1

Glare doesn’t even require a stored program control PABX, so problems that require rebooting are not glare or not just glare.

It’s just possible that you are assuming that outgoing landline calls will clear as soon as the callee hangs up. That’s not necessarily true, even if you have disconnect supervision. It is not true for calls to PSTN numbers (at least to non PABX ones) in the UK.

I think kewlstart is an adaptive system. What matters is what the central office actually uses.

(Note ring here refers to the barrel of a jack plug, not to ringing current.)