7.2. GS BT-100 behind NAT Router running Siproxd

Scenario:

private IP address range             :          Internet
10.0.0.x                             :          (public IP address range)
                                     :
                                     :         foo.bar.org
+-------------+               +--------------+
!             !.10         .1 ! masquerading ! publicIP
! SIP UA      !---------------! Firewall     !------------>>  
! BT-100      !               ! siproxd      !
+-------------+               +--------------+
                          eth0       :        ppp0

Siproxd is running on the same host as the masquerading firewall. The SIP phone is a Grandstream BudgeTone-100. In this example the external SIP registrar used is sipphone.com.

siproxd.conf:

if_inbound  = eth0
if_outbound = ppp0
hosts_allow_reg = 10.0.0.0/24
sip_listen_port = 5060
daemonize = 1
silence_log = 1
user = siproxd
registration_file = /var/lib/siproxd_registrations
pid_file = /var/run/siproxd/siproxd.pid
rtp_proxy_enable = 1
rtp_port_low  = 7070
rtp_port_high = 7089
rtp_timeout = 300
default_expires = 600
debug_level = 0
debug_port = 0

Firewall configuration (iptables):

# allow incoming SIP and RTP traffic
iptables -A INPUT -m udp -p udp -i ppp0 --dport 5060      -j ACCEPT
iptables -A INPUT -m udp -p udp -i ppp0 --dport 7070:7089 -j ACCEPT

Phone configuration (only the relevant items are listed):

IP Address:             10.0.0.10
Subnet Mask:            255.255.255.0
Default Router: 10.0.0.1
DNS Server 1:           <DNS Server of your Internet provider>
SIP Server:             proxy01.sipphone.com
Outbound Proxy: 10.0.0.1
SIP User ID:            1747669xxxx
Authenticate ID:        1747660xxxx
Authenticate Passwd:    *********
Name:                   Your Name Here
Use DNS SRV:            no
User ID is phone #:     no
Sip Registration:       yes
Unregister on reboot:no
Register expiration:    60
Early Dial:             no
local SIP port: 5060
local RTP port: 5004
Use random port:        yes
NAT traversal:  no
Use NAT IP:             <empty>
Subscribe for MWI:      No
Send DTMF:              via RTP (RFC2833)