[asterisk-users] SIP/2.0 403 Relaying denied

[Rene]

Hi all,

I am trying to register myself to my VOIP provider (budgetphone.nl) so I
can accept inbound calls. However, using "sip debug" I get the following
error:

<-- SIP read from 81.23.228.150:5060:
SIP/2.0 403 Relaying denied
Via: SIP/2.0/UDP 192.168.0.3:5060;branch=z9hG4bK65bc02f0;rport=1048
From: "asterisk" <sip:asterisk at 192.168.0.3>;tag=as67980981
To: <sip:sip.budgetphone.nl>;tag=48cd709ae35c71b0e4d33846252f55ea.b365
Call-ID: 709ffae32f15f8f26cb0a5243acf38af at 192.168.0.3
CSeq: 102 OPTIONS
Server: OpenSer (1.0.2-tls (i386/linux))
Content-Length: 0

I am behind a NAT device which forwards port 5060 to my asterisk server.
Outgoing calls do work OK.

This is what I have in my sip.conf:
register => 3172xxxxxx:password at budgetphone.nl

When I do "sip show registry" I do not see anything registered.
Does someone know what "SIP/2.0 403 Relaying denied" means?

Thanks,
Rene