[asterisk-users] WiFi SIP phones

[Anselm Martin Hoffmeister]

Am Donnerstag, den 24.05.2007, 08:23 +0300 schrieb Cosmin Prund:
> > -----Original Message-----
> > From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-
> > bounces at lists.digium.com] On Behalf Of Remco Post
> > Sent: Wednesday, May 23, 2007 10:47 PM
> > To: Asterisk Users Mailing List - Non-Commercial Discussion
> > Subject: Re: [asterisk-users] WiFi SIP phones
> > 
> > Tony Plack wrote:
> > > Are the DECT phones two channel or do they share a channel like most
> > > other portable phones?
> > 
> > DECT is a digital standard, quite distantly comparable to GSM. There
> > are
> > multiple channels (I believe the standard allows for 12 channels, but
> > the last time I actually worked on DECT is ages ago). A siemens S450IP
> > can have up two 6 handsets with 2 'external' (SIP or POTS) phonecalls
> > concurently. You cannot decline a phonecall, but you can ignore it.
> 
> I'm curious: is the impossibility of declining an call a DECT limitation
> or is it that "agest ago" DECT phones were backed by POTS line and
> declining a call would make no sense since the POTS doesn't support it? 

For ISDN DECT phones (like the Siemens Gigaset S100isdn), there is very
well the option to reject a call. Mine displays "reject" on the left
button and "stop ringing" on the right button. Pressing "reject" will
immediately give busy to the opposite side.

So: No, it is not a DECT limitation, but handsets that are made for
analog base stations probably do not have that button, and it might be a
Siemens propriatory addition.

BTW I use that DECT phone behind a Fritz!Box, which serves as ISDN ATA
on my *, and pressing "reject" yields

    -- Executing Dial("...") in new stack
    -- Called sip501
    -- SIP/sip501-08459061 is ringing
[...]
    -- Got SIP response 486 "Busy Here" back from 80.136.199.41
    -- SIP/sip501-08459061 is busy

BR
Anselm