Asterisk with Snom Interface call redirect

Hi.
I try to redirect a call to an extern phone from Snom Interface, the connection is ok. but i have no sound on both devices.
Can you help me.

Sip.conf

[code][general]
port=5060
bindaddr=0.0.0.0
context=sonstiges
allow=ulaw
encryption=no

register => 4144xxxxx8:123456@pro2.voipgateway.org/4144xxxxx8
register => 4144xxxxx7:123456@pro2.voipgateway.org/4144xxxxx7

[2001] ; maloc Festnetz
type=peer
context=maloc-telefon
secret=1234
host=dynamic

[2002] ; roler Festnetz
type=peer
context=roler-telefon
secret=1234
host=dynamic

[2003] ; roler Handy
type=peer
context=roler-handy
secret=1234
host=dynamic

[roler-sip-account]
type=friend
context=incomming
username=4144xxxxx8
fromuser=4144xxxxx8
secret=unvf9jys
host=pro2.voipgateway.org
fromdomain=pro2.voipgateway.org
qualify=yes
insecure=port,invite
nat=yes

[maloc-sip-account]
type=friend
context=incomming
username=4144xxxxx7
fromuser=4144xxxxx7
secret=thwx2qtc
host=pro2.voipgateway.org
insecure=port,invite
fromdomain=pro2.voipgateway.org
qualify=yes
nat=yes[/code]

Extensions.conf

[code][sonstige]

[roler-telefon]
exten => 2002,1,Dial(SIP/2002,60)
exten => _0[1-9].,1,Dial(SIP/${EXTEN}@roler-sip-account)
include=>internal

[roler-handy]
exten => 2003,1,Dial(SIP/2003,60)
exten => _0[1-9].,1,Dial(SIP/${EXTEN}@roler-sip-account)
include=>internal

[maloc-telefon]
exten => 2001,1,Dial(SIP/2001,60)
exten => _0[1-9].,1,Dial(SIP/${EXTEN}@maloc-sip-account)
include=>internal

[internal]
exten => _XXXX,1,Dial(SIP/${EXTEN})

[incomming]
exten => 4144xxxxxx8,1,Dial(SIP/2002&SIP/2003)
exten => 4144xxxxxx7,1,Dial(SIP/2001)[/code]

Faults