asterisk users - Apr 2005 - prevent callerid spoofing between asterisks

Hi all

For example here is asterisk-A sip.conf:
[123456]
type=friend
secret=xxyyzz
nat=1
qualify=100
host=dynamic
canreinvite=no
callerid="" <123456>
context=sipphone
dtmfmode=rfc2833

Sip-phone can make and receive calls and callerid 
value overrides phones config here, thats nice.

OK, lets set up an Asterisk-B as sip peer and also send all our
outgoing traffic to Asterisk-A, useing same the sip account.

#Asterisk-B sip.conf:
register => 123456:xxyyzz@ip.adr.of.asteriskA
[asteriskA]
type=friend
username=123456
secret=xxyyzz
host=ip.adr.of.asteriskA

#Asterisk-B extensions.conf:
exten => _XXX.,1,Dial(SIP/asteriskA/${EXTEN})


Now if I make a call from asterisk-B to asterisk-A, I'm able 
to spoof callerid, because in this case asterisk-A doesn't 
override callerid. How to prevent that?

Thanks.
Elkur

elkur wrote:
>Hi all
>
>For example here is asterisk-A sip.conf:
>[123456]
>type=friend
>secret=xxyyzz
>nat=1
>qualify=100
>host=dynamic
>canreinvite=no
>callerid="" <123456>
>context=sipphone
>dtmfmode=rfc2833
>
>Sip-phone can make and receive calls and callerid 
>value overrides phones config here, thats nice.
>
>OK, lets set up an Asterisk-B as sip peer and also send all our
>outgoing traffic to Asterisk-A, useing same the sip account.
>
>#Asterisk-B sip.conf:
>register => 123456:xxyyzz@ip.adr.of.asteriskA
>[asteriskA]
>type=friend
>username=123456
>secret=xxyyzz
>host=ip.adr.of.asteriskA
>
>#Asterisk-B extensions.conf:
>exten => _XXX.,1,Dial(SIP/asteriskA/${EXTEN})
>
>
>Now if I make a call from asterisk-B to asterisk-A, I'm able 
>to spoof callerid, because in this case asterisk-A doesn't 
>override callerid. How to prevent that?
>
>Thanks.
>Elku
>
Setup the dialplan on the "protected" * server to manually set the 
callerid.  That will over ride any value sent to it by the remote * server.