Two Asterisk servers on the same LAN

Is it possible to put two Asterisk servers on the same LAN and have them
handle external calls from different numbers?

I would have thought it would just be a matter of using a different SIP
port and different RTP ranges for each box and arrange port forwarding
on my router to each one. My ITSP is listening for registers on 5060,
so I figured I’d have to use that port with the register command, but I
figured my box could listen on another port say 5070. It didn’t work
though.

Here’s my set up:
SuSE 10.2
Asterisk 1.4.17
I’m port forwarding 5060 & 10000-20000 to BOX A (192.168.2.160)
I’m port forwarding 5070 & 20001-25000 to BOX B (192.168.2.170)

BOX B below didn’t work. BOX A works fine. Any pointers?

Thanks,
Hugh

BOX A - 192.168.2.160

rtp.conf


rtpstart=10000
rtpend=20000

sip.conf


[general]
;
context=incoming-sip

bindport=5060
bindaddr=0.0.0.0
maxexpirey=3600
defaultexpirey=3600
notifymimetype=text/plain
rtptimeout=60
rtpholdtimeout=300
disallow=all
allow=ulaw
canreinvite=no

;
register=>6479999999:@:5060/6479999999
;
externip= ;Outside address
localnet=192.168.0.160/255.255.255.0 ;Inside Network
;
[6479999999]
type=peer
auth=md5
username=6479999999
fromuser=6479999999
fromdomain=
secret=
host=sip.
port=5060
nat=yes
canreinvite=no
qualify=no
disallow=all
allow=ulaw
dtmfmode=rfc2833
insecure=port,invite
context=incoming-sip

BOX B - 192.168.2.170

rtp.conf


rtpstart=20001
rtpend=25000

sip.conf


[general]
;
context=incoming-sip
bindport=5070
bindaddr=0.0.0.0
maxexpirey=3600
defaultexpirey=3600
notifymimetype=text/plain
rtptimeout=60
rtpholdtimeout=300
disallow=all
allow=ulaw
canreinvite=no
;
register=>6139999999:@:5060/6139999999
;
externip= ;Outside address
localnet=192.168.0.170/255.255.255.0 ;Inside Network
;
[6139999999]
type=peer
auth=md5
username=6139999999
fromuser=6139999999
fromdomain=
secret=
host=sip.
port=5070
nat=yes
canreinvite=no
qualify=no
disallow=all
allow=ulaw
dtmfmode=rfc2833
insecure=port,invite
context=incoming-sip