call transfer

kyriakos · #1 (**permalink**) July 1st, 2007, 04:42 PM

Hello

I am trying to fix an IP PBX network in my small company
I have downloaded Brekeke software IP PBX and i am using 4 voip phones and three ATA devices. Everything works fine. i manage to do 3 way conference call forwarding but have problems with call transfer. When i try to transfer a call in case of a blind transfer i call to the number i need to transfer the call but have no response.i wait for almost half a minute and then i hear the busy tone.#

When i try the attended transfer, i dial the number where i want to transfer the call talk to that number, but when i try to finish the transfer of the call i get the same results as before.

Do you have any ideas where i should look in order to find the problem?
Please give me any hints you have.
thanks

humba3 · #2 (**permalink**) July 1st, 2007, 07:20 PM

Transferring is one of the basic (I'd say so coming from an enterprise telephony background) functions, yet unfortunately it's not part of the core SIP spec but is defined in an external RFC and it appears that different devices have different implementations - so it might be a conflict between the PBX and the devices you're using, and in case the problem arises when you have an external call coming in via VoIP, your IPTSP might also be part of the problem. Especially for external calls, I've found to get a lot more reliable results when I proxy the media in my PBX (so the audio always passes through my PBX.. that has the additional advantage that my QoS rule for the PBX also applies to every incoming and outgoing call and I don't have to add additional rules for each phone (my router doesn't support 802.1q and DSCP) - then the media flow between IPTSP and my PBX remains in place when I transfer the call around between my various phones.

Cybertoy · #3 (**permalink**) July 3rd, 2007, 06:37 PM

I don't know the PBX that you are using. I had transfer issues with asterisk though and it turned out that there is a seperate transfer context and if that's not defined to your usual context that you make phone calls with then you cannot transfer the call. What you describe is exactly what happened in my asterisk.