asterisk users - Apr 2004 - * behind NAT - FWD or ICH but not both

Hi,

I just got FWD and ICH behind a Linux NAT firewall working. The funny 
thing is that I cannot get them to _both_ work at the same time. Its 
either one or the other.

The setup is using a local Sipura and the standard extension setup 
(ICH=6, FWD=7) as documented on some sample * configs. The firewall 
forwards 5060:5070 ports and the rtp port range udp/tcp to the * server.

I can use FWD (time service, echo server without problems when I add 
this to sip.conf:

;
localnet=192.168.1.0            ; address space for local (natted) network
localmask=255.255.255.0         ; netmask for local (natted) network
externip=a.b.c.d    ; for a.b.c.d I substitute the domain name of my router
outside_addr=a.b.c.d; as above
bindaddr=192.168.1.2            ; where 192.168.0.2 is the IP address of  *
;

ICH however now responds with:

-- Got SIP response 481 "Call Leg/Transaction Does Not Exist" back
from
213.137.73.140


If I leave the above section out, ICH works fine (i.e. outbound to my 
answering machine) but I do not hear anything from FWDs time service 
anymore.


Any suggestions? - I use asterisk compiled from todays CVS.

bye
Andreas