Audio Problem with SIP VoIP

[jdfish]

Hi Everyone,

 

I'm kind of at wits end with this issue and was hoping someone could shed some light.

 

I'm using IVM 4.0.2 and have setup a SIP account with ISPhone.com.au on it for inbound and outbound calls.

 

If I make an outbound call from IVM to any number, it works fine, and you can hear everyone without an issue.

 

If I make an inbound call from the same SIP server (like another user on ISPhone), not a problem, all works well too.

 

However, if I make an inbound call to the IVM from the PSTN, I hear nothing at all. I've read through all the forums and tried various things. I have no Internet firewall on the machine I'm using, it has a real public IP address, I've changed SIP and RTP ports and no success.

 

I rang my SIP provider and they said that if one is using a-law or u-law then it needs to use inband dtmf and to make sure that this is the case. However there's no option for that in IVM? He tried dialing in and said that when dialing from PSTN to the IVM, it get's bogged down with this inband issue.

 

Has anyone else had a similar problem and/or a resolution?

 

Many thanks.

[SmOke_N]

I rang my SIP provider and they said that if one is using a-law or u-law then it needs to use inband dtmf and to make sure that this is the case. However there's no option for that in IVM? He tried dialing in and said that when dialing from PSTN to the IVM, it get's bogged down with this inband issue.

 

Has anyone else had a similar problem and/or a resolution?

I came looking for this exact answer tonight, started typing up a new topic, and realized I should check the boards first.

 

My provider (ViaTalk) said the same exact thing... "Set the dtmf to "inband"" .... after 4 hours of google/nch site/help/forum I've not yet found where to change these settings as of yet.

[jdfish]

I told ISPhone that Engin and Mynetfone work fine (their competitors in .au).

 

To the credit of ISPhone, they assigned an engineer, who then went through the process of installing IVM on one of his computers and found that as per my findings, that it was in fact their PSTN-VoIP carrier.

 

He's now raising it with them to see what in the world is going on. It could be between the SS7->VoIP conversion that's causing this to be an issue.

 

I suppose it could be easier for NCH to make the changes, however I think ISPhone will probably get around to it before NCH does.

 

I'd prefer use ISPhone as the service I ultimately want to plonk the IVM is a number from the ISPhone numbering range of PSTN numbers (and number portability on VoIP is pretty much impossible at the moment in .au). Having said that, I have configured both an Engin service and Mynetfone service as additional VoIP accounts in IVM and they work fine from the PSTN.

 

So, to cut a long story short, you can't do anything about it but churn or encourage your VoIP provider and/or NCH to enforce compatibility between themselves.

[Guest nchto]

If you're able to post SIP Traces of the problem it may shed some light on the situation.