[Asterisk-Users] IP PHONE with chip PA1688 and IAX2 Authentication

[Androtech]

Dear All,
I bought one IP PHONE from Integrated Networks which was showed to wiki too:
http://www.voip-info.org/tiki-index.php?page=Intergrated-Networks
I have problems with the Asterisk authentication. It does't want to LOG IN 
to Asterisk; it always says "LOG ON FAILED". I'm using the IAX2 protocol and 
all paramters seems to be correct.
Does somebody use the same IP PHONE with Asterisk and IAX2? Can someone tell 
me the right configuration for it?

My actual configuration is:

locale ip: 192.168.0.75
subnet mask: 255.255.255.0
router ip: 192.168.0.1
dns: 192.168.0.1

protocol: iax2
service type: common
use service marked
service address: 192.168.0.1:4569
nat trasversal: disabled
phone number: 103
account: ipphone
pin: test
register port: 4569
signal port:1701
control port:1721
rtp port:1721
local type: auto

the phone firmware is V.1.38.009

My Asterisk extension is:

[ipphone]
type=friend
username=ipphone
secret=test
auth=md5
host=dynamic
context=fullaccess
mailbox=103
callerid="ipphone"<103>

Thanks for any help
Regards,