[asterisk-users] Attended transfer problems

[James Lamanna]

Hi,
A couple of our customers are having issues with doing attended transfers.
What happens is Caller A receives a call, they transfer to Caller B,
tell Caller B who is calling, etc.. and then
hit the "Transfer" key again to transfer the call.
Caller A's side hangs up as expected, but the call is never completed
to Caller B, and the call is dropped.
Blind transfers at these couple companies work fine.
The transfers are occuring on Linksys 942/962 phones, and I have about
20 other customers using these same phones that
have no problems.

My only guess so far is that in both of these cases, the SOHO
firewalls that these companies are using (the * Box is on a public
internet IP),
is rewriting the VIA header to [firewall address]:[firewall port].
Could this be causing the issue?
I'm going to try replacing the firewall with ones I know don't do
packet rewriting, so maybe that is the answer,
but any additional insight would be of a big help!

Thanks.

-- James