no sound in transferred calls to external numbers

[AlfonsoSF]

Hi everybody.

I have experiencing the same problem in two diferent IPOffice 500 V2.

In both cases external lines are a sip trunk.

In the first I have a dial to extension first step. If i configure a Twining with a user and his home telefon number and I call to hi9s extension, the call is twinned correctly and I can talk with him.
But if the call follows the vocice mail pro flow and it is transferred to a grup, which have the twinned user, the call is made to the remote twinned number, it rings, the user answer, but we have no sound.


In the second case, we have an embebded voice mail .
Two time profiles.
An incoming call route tansferring calls for the first time-profile to a cellular number and transferring to another cellular for the second time-profile.

When the transfer is transferred, it rings, it is picked-up and .... no sound. In this case we can say that no media packets are arrivet to the carrier. (Colt people say). Of course, a normal call to those cellular numbers are OK.

Is there any reason for it ? (posibly in both cases, the reason is the same)

Thanks in advanced.

 

[derfloh]

Did you enable RTP Keepalives within the LAN interface configuration?

IP Office remote service
Fixed price SIP trunk configuration
CLI based call blocking
SCN fallback over PSTN

 

[pccsipoffice]

The vast majority of one-way or no-way audio problems are a result of the blockage of RTP ports for the voice stream.

 

[AlfonsoSF]

But it's important to note that normal calls work. Only external transfers don't work

By other hand, TRTCP control on port 5005 is activated .

Curiously if I launch the "Manager" in Spanish, "keepalive" shows "deactivated". If I launch it in English "keepalive" is "RTP-RTCP". Only opening the configuration.


Once verified that keep-alive is in RTP-RTCP , I make an incoming call route . Incoming CLI=my cellular. destination=my fixed line. Line grup ID=SIP trunk.
I call to the IPO from my cellular, I answer at my fixed line, no audio.

 

[derfloh]

But are keepalives now enabled or not?



IP Office remote service
Fixed price SIP trunk configuration
CLI based call blocking
SCN fallback over PSTN

 

[derfloh]

Or do you have something blacklisted?

IP Office remote service
Fixed price SIP trunk configuration
CLI based call blocking
SCN fallback over PSTN

 

[AlfonsoSF]

Test are with keepalives enabled.

No blacklist.

The problem only appear when the call is transferred to a external number.
A normal call to this number work.

 

[derfloh]

That's the most complicated scenario regarding RTP handling.

Then it might be something with the network Topology...

IP Office remote service
Fixed price SIP trunk configuration
CLI based call blocking
SCN fallback over PSTN

 

[AlfonsoSF]

I can't find what to do

Which would be a correct network tiopology scenario ?

 

[derfloh]

Mostly static port blocking with the public IP configured.

IP Office remote service
Fixed price SIP trunk configuration
CLI based call blocking
SCN fallback over PSTN

 

[AlfonsoSF]

thanks Derfloh.

Could you explain it me a little bit more? Do you mean at the IPO or the firewall?
When the call is made normally from a terminal , it's ok. I have only problems when the call is transferred to a external number from the incomming call routing, or twinning when the call is transferred to a twinned extension.

 

[bahmonkeys]

Remove Direct Media Path option to allow the PBX to process Audio Ports

 

[AlfonsoSF]

This option is not selected

 

[bahmonkeys]

Is the twinned number an extension internally or externally? If its an external softclient make sure the RTP ports are opened in the Firewall. Use the monitor to trace the audio streams

 

[AlfonsoSF]

the extension twinned is a cellular line. Ports RTP are opened . All trafic from carrier and only from carrier is forwarded to the IPO in a separate LAN subnet and all traffic to the carrier is allowed.

 

[derfloh]

I meant within IPO LAN interface configuration.

IP Office remote service
Fixed price SIP trunk configuration
CLI based call blocking
SCN fallback over PSTN

 

[janni78]

Do a SIP trace with SysMonitor, most of the times this will show why media isn't working as expected.

"Trying is the first step to failure..." - Homer