Provider perspective: missing feature?

The Guide (<URL:
http://siproxd.sourceforge.net/siproxd_guide/siproxd_guide_c7s3.html>)
describes the setup '7.3. GS BT-100 with Siproxd running "in front of" a
NAT router'.

I have the reverse situation: 'Asterisk with Siproxd running "in front
of" of NAT router', where there is no external registrar. In other
words, I'm building this setup:


   +-----------+
   | SIP Phone |
   +-----+-----+
         |
     ____|________
  __(             )__
 (    Public IP      )
  (_________________)
         |
         | abc.myhome.net:5060
      +--+--+
      | NAT |
      +--+--+
         |
         | 192.168.100.202:5061
    +----+----+
    | siproxd |
    +----+----+
         |
         | 192.168.100.202:5060
    +----+-----+
    | asterisk |
    +----------+

I can't seem to find a configuration parameter that would make siproxd
advertise abc.company.com:5060 instead of 192.168.100.202:5061.

Running siproxd on the NAT would solve the problem but is not an option
for me.

My current siproxd.conf is enclosed.


Marko

===siproxd begin========================================================
if_inbound  = eth4
if_outbound = eth4
hosts_allow_reg = 0.0.0.0/0
sip_listen_port = 5061
daemonize = 0
silence_log = 0
user = nobody
registration_file = /var/lib/siproxd/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
outbound_proxy_host = 192.168.100.202
outbound_proxy_port = 5060
===siproxd end==========================================================

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