Australian Communications Forum
Sign up Calendar Latest Topics
 
 
 


Reply
  Author   Comment  
R4

Founder
Registered:
Posts: 218
Reply with quote  #1 

Just a heads up guys, I have a customer who has been complaining of fax failures since they went over to Business SIP. The fax service is delivered over a separate ATA but the customer was getting constant fax failures.

It turns out that the customer who is a medical practice, faxes mainly to a medical imaging company who uses a Vocus fax stream type service and due to a handshaking issue with that service which only applies to faxes from a SIP service, it switches to a wrong mode and the fax fails. I am not 100% sure of the technicalities but Telstra is liasing with Vocus to resolve the issue. So if you have customers complaining of faxes failing, this could be the issue!

R4

Founder
Registered:
Posts: 218
Reply with quote  #2 
Ok so I have gleaned some more info here. apparently it is something to do with the initial handshaking where the fax tries to negotiate speed, I believe the thing is it tries to negotiate as super group3 but becausee the sending party is on voip, it can't communicate at the speeds for that and needs to train down. However the receiving end doesn't try to train down and so the session fails! Telstra is apparently reaching out to Vocus to try to resolve the issue!
R4

Founder
Registered:
Posts: 218
Reply with quote  #3 
Ok so the latest issue is that Telstra in their infinite wisdom have decided not to support 9 digits on business sip. So far this has caused issues on Alcatel and Panasonic systems.
R4

Founder
Registered:
Posts: 218
Reply with quote  #4 
We have discovered a new issue on Business SIP. A customer was reporting that they could not dial 131 numbers so we were asked to do a Wireshark trace and send it to them. They came back to us and said the PABX was sending a 00. This was where I got involved and had a look at the trace ant there was no 00 to be seen, in fact the setup was perfectly normal and there was even an RTP stream but no "BYE" or sign of a clear down. We then tried to dial 131 numbers on our own B Sip service and found out that we had the same issue on a completely different system. So we decided to look into other possible causes and as there are blocks you can set in the portal, we decided to play with those settings. There were only two things being blocked, 190 numbers and Operator assisted calls. We tried 190 first simply because it started with the same digit but no joy, we hit the jackpot with operator assisted calls even though the list of affected numbers didn't include 131 numbers.

So if your customer has a need for 131 calls you may need to turn off the blocking of Operator assisted calls with all the risks that entails!
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.