I'm really struggling to get my Grandstream 1450 HD to work on my BT business broadband. I have put the sip details into the web configuration page for the phone, but I'm unable to get it to work (I've tried different combinations of settings - with/without authentication, different proxy addresses etc).
The configuration details I got from the BT bbv configuration page are:
SIPTransportProtocol=UDP
SIPTransportPort=5060
SIPRegistrarAddress=bmnhb-03.bt.com
SIPRegistrarPort=5060
SIPOutboundProxyAddress=www.bbvservice-560346.bt.com
SIPOutboundProxyPort=5060
SIPProxyAddress=bmnhb-03.bt.com
SIPProxyPort=5060
SIPPhoneNumber1=056xxxxxxxx
SIPCallerName1=
SIPUsername1=056xxxxxxxx
SIPPassword1=xxxxx
SIPPhoneNumber2=
SIPCallerName2=
SIPUsername2=
SIPPassword2=
SIPHashB=xxxx
SIPHashC=xxxxx
SIPHashD=xxxx
SIPHash=xxxxx
When I try and dial out i get a "Failed Response" message on the phone. I have a non-voip phone plugged in to the back of the router via a filter which works ok. I have had a landline number ported across as a voip number on the line (which is the number that appears when using the non-voip phone handset).
My phone number starts 056 instead of 44 - does that mean I have to use 44056XXXXXX?
And does my username have to be 056XXXXX or 44056XXXXX@btsip.bt.com?
Should I be using bmnhb-03.bt.com or btsip.bt.com or sip.bt.com as the server?
Help is very appreciated!
Thanks
From what I know, SIP connection must be peered from end to end. Looks like intensive troubleshooting is needed for this issue. Have you contacted support? Usually, they will replicate the issue on their end and check the logs at the same time. 
