[Asterisk-Users] Cannot use # key to transfer calls

[Barton Hodges]

asterisk-users-admin at lists.digium.com wrote:
> I cannot use the # key to transfer a call. I have two kinds of SIP
> phones, Grandstream and IpDialog, and the # key cannot be used to
> transfer on either one. If I press the # key during a call, I hear
> the touchtone for it, but Asterisk does nothing.
> The documentation for parking a call says that I must first transfer
> the call using #, so that's why I need this feature to work. Thanks
> for any pointers.
> 
> -Ron Dutt

Make sure your Dial() line contains the 'T' and/or 't' options.

Also make sure that your DTMF entries in sip.conf match the phones.

I've found that with Grandstream HandyTones, the only reliable method
of using '#' to transfer is by using inband DTMF, which means using
ULAW/ALAW as well.