[asterisk-users] sip_write warning when executing Pickup of CAPI

[Armin Schindler]

On Tue, 5 Dec 2006, Tom Fanning wrote:
> I'm trying to pick up a ringing SIP phone (203) across the office with
> exten => *9,1,Pickup(783743)
>
> where 783743 is the local part of the number that our ISDN works on.
> 
> I tried all of these first:
> 
> exten => *9,1,Pickup(203)
> 
> exten => *9,1,Pickup(SIP/203)
> 
> exten => *9,1,Pickup(203 at internal)
> 
> and got a "declined" message back from my phone (snom 300), so I then
> switched to picking up the ringing ISDN line (it's BT ISDN2e on a pair of
> Eicon Diva BRI-2M cards)
> 
> The Pickup(783743) works (the phone across the room stops ringing), but the
> calling party gets a nasty distorted noise back down the phone, and I get
> dozens of these messages:
> 
> Dec  5 11:37:50 WARNING[26972]: chan_sip.c:2561 sip_write: Asked to transmit
> frame type 64, while native formats is 4 (read/write = 64/64)

This sounds like a bug in Asterisk. chan-capi only accepts one format (alaw 
or ulaw), which is configured as native format.
Asterisk here sends frames of type 64 (SLINEAR), which is wrong and not 
accepted by chan-capi.
I cannot tell why Asterisk is doing that.

Armin