NCP500 - No outbound calls on SIP trunks (intermittent) 1

[keypulse]

I had a customer report today that when they pressed 9 to dial out the display on their phone showed "Line 6" as expected but there was no comfort dial tone. Attempting to dial the number anyway would fail. This sorted itself out, then happened a few more times during the day.

There are 6 channels of Gamma SIP, lines hunt backwards. NCP on latest firmware. Nothing at all in the error logs.

Would this indicate a system fault or a line fault?

 

[Raul PG]

it maybe a codec issues, check your provider supported codecs and prioritize them with the provider instructions, or maybe firewall issues, since this is a internet based lines, check the firewall or modem, check if the sip ports are not filtered at the firewall and the sip passthrough is disabled, also try by setting the pbx ip as dmz, if the sip calls works then are filtered by the firewall and you should open the access to the pbx at the firewall. And don´t forget to close the dmz after testing and set the firewall rules, it is important not to have the pbx ports open at the internet without some kind of control.