[Asterisk-Users] Announced Call Transfer

[Rich Adamson]

> > Michael T Farnworth wrote:
> > 
> > >more expensive phone in reception but leave the other people on the cheap 
> > >Grandstream phones?
> > >
> > Yes, I have found the Snom200 does consultative transfers well..
> > 
> > >Couldn't this problem be solved with an asterisk upgrade?
> > >
> > No, Its an issue that is handled on the phone..
> 
> Perhaps I am confused, but I tend to believe that Asterisk sits in the
> middle of all these calls.  So when I press the # key for transfer it

In many cases, that's a bad assumption, but it depends on your config.

Unless you've purposefully configured something different, asterisk is
"not" in the middle. Once a call is established, the communications
(packet flows) happen directly between the two sip phones and does not
pass through asterisk. So the problem becomes an issue of the phone
itself. What has the phone been programmed to do when "any" key has
been pressed (regardless of whether its the # key or something else)?

The discussion suggests the Grandstream phones have not been programmed
to handle transfers. (I don't have one therefore I don't have a clue as
to whether that happens to be the result of the vendor, or the person
that has implemented the phone doesn't have the knowledge or documentation
to do it.)

If one purposefully configures asterisk to force all packet flows through
asterisk (instead of allowing two phones to communicate directly), then
you're burning asterisk cycles handling every single packet and that
certainly has an impact on how many simultanous calls can be handled by
the system. Your milage may vary.