[asterisk-users] weird caller ID addition when no caller id is received for incoming call

[ilker Aktuna]

Hi,

I am using a SPA 3000 as a PSTN gateway. Incoming PSTN calls are connected 
to Asterisk through SPA 3000 (it has a fxo port) via SIP.
Everything is fine with this call scenario, but if the incoming PSTN call 
has no caller ID, then Asterisk receives the call with contact header and 
from header as "sip:192.168.254.5"
When it sends the same call to an internal extension Asterisk adds a caller 
ID "192168254254" to both from and contact fields. 
"sip:192168254254 at 192.168.254.5"

I  checked all configuration files but couldn't find anything similar to 
this additional caller ID.
Is it a default string ? How can I remove it ?

If anyone is interested in analyzing the network trace I can send it to a 
given email address.

Thanks