IP Telephony - NBX
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No audio on Digital Line Cards from Remote phones

Occasional Contributor

No audio on Digital Line Cards from Remote phones

I have an NBX  with v6.5 software.  We have 4 sites - central site has the NBX and a Digital line card.

VLAN Tagging is enabled on the switches.  Using IP On-the-Fly.  Have configure the NBX to use VLAN 2 with Tagging enabled.  Have configured VLAN 2 and proper IP information on the remote phones at remote sites.  Local phones have no config entered.  Calling from site to site works fine - extension to extension is good.

When you are at the central site, you can make outbound calls out the PRI with no problem.  However, if you make an outbound call from the remote site out the PRI, the phone rings, but as soon as the far end picks up there is no audio.

If I DISABLE VLAN on the NBX, all calls work.  Seems like the DLC is not tagging for VLAN 2 like the phones because I see in the IP Status screen, it has the IP Address of the subnet for VLAN 1, and even though it is LOCAL to the NBX, it is IP Online.

How come the DLC is not tagging VLAN?  I see nowhere to set the VLAN ID, or enable VLAN at all.

Any Suggestions?



Frequent Advisor

Re: No audio on Digital Line Cards from Remote phones

Hi Bortiqaui

Sounds like network configuration/communication issue.

While maintaining the NBX configuration to VLAN Tagging enabled with voice VLAN=2, try configuring the switch interface where the DLC is connected to be Link-type= Access and make it access vlan 2. This should solve the problem. If not, then it will help much if you provide more details of your NBX IP settings and IP-on-the-fly setting, as well as configuration of the switch interfaces where NBX, DLC Chassis and routers are connected. Also, router (responsible for inter-site routing) configuration is needed.