Delay in grandstream transfer

[hoosier1077]

Hello,
I have about 60 grandstream gxp1450's running newest firmware, and a grandstream 2120 at reception desk running newest firmware. Also have paid version of 3cx with sp4 update installed, waiting to do sp5 this weekend. When I make a call from any of the 1450's, sound quality is fine and there is no delay. However when a call is blind transfered from the reception 2120 to any of the 1450's, the user experiences a bad delay on the call, where they may not hear for first few seconds, and then hear a bad echo of themselves after talking. Im using broadvox siptrunk service, and reading their setup has me use pbx delivers audio, and support reinvite. On the extensions setup on the 3cx server I have the extensions setup to NOT use the pbx to deliver audio, and to support reinvites as well. Can anyone please help me determine if its just a incorrect setup with those mentioned above. Again, this only happens when reception transfers a call to the extension. If the ext just calls out on their own, call quality is fine. Thanks in advance...

 

[GSsupport]

Hello,

Could you please confirm which firmware exactly is loaded to your phones?
You mentionned that the issue is only when transferring the call from receptionist's phone, did you make any test using another GXP1450? What's the results?
Can you also run a test using attended transfer and see the results?
Are you connecting an EXT module to the receptionist's phone or configuring BLFs on the phone?
Can you tell us which codec you are using?
What is the occurence of the issue?

I would suggest you to open a ticket using Grandstream website to get support :
http://www.grandstream.com/support/submit-a-ticket

(Please copy the posts in the ticket and your answers)

Best regards,
GSsupport