running siproxd "in front" of a NAT router

Hi there,

A number of people have asked if it is not possible to run siproxd
on a host *inside* the private network and *not* of the NAT router
itself. The reason for these requests is, most of home users use some
out-of-the-box ADSL router that can not run any additional software.

I'm currently working to implement such functionality into siproxd,
so it can be run "in front" (or behind - depends on the point of view)
of an NAT router:

  local (private)
  network
                       +-------------+
-----+------------+----| ADSL router |------------>> Internet
     |            |    +-------------+
     |            |
  +------+    +-------+
  | SIP  |    |siproxd|
  |client|    +-------+
  +------+


Anyone looking for this feature is encouraged to download the latest
snapshot. Currently no documentation exists, but following I include
a short list of things to consider.


On your Router:
- forward incoming data for UDP/5060 to the siproxd host
- forward incoming data for UDP/7070-7079 to the siproxd host

Siproxd config:
- set both, 'if_inbound' and 'if_outbound' to the inbound interface
  (usually the only network interface on that box)
- additionally define 'host_outbound' with the IP address (or 
  hostname) of your public IP. You may want use a DYNDNS hostname
  to be able to deal with dynamically changing IP addresses.

I was able to place an outgoing call via sipphone.com to my normal
telephone line and got two way audio - it can't be that bad then :-)

Something that currently will fail is using symmetric RTP. If you can
configure this in your SIP client, disable it.

/Thomas


-- 
GnuPG: pub  1024D/87BCDC94 2000-03-19 Thomas Ries <[email protected]>
-      Fingerprint = 13D1 19F5 77D0 4CEC 8D3F  A24E 09FC C18A 87BC DC94
-      Key via pgp.openpkg.org / http://www.ries.ch.vu/87BCDC94.pub
VoIP:  sip:17476691342-rne+wJe3e/u3Jhga2bR/9VaTQe2KTcn/@public.gmane.org | sip:[email protected]

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (GNU/Linux)

iD8DBQBCJN+5CfzBioe83JQRAsn4AJ4pnXiu9E21DYk5usmYDTR57O/NkACfXTaA
DVQmxsE4PbQJy+nlf4DrrBA=
=+r7B
-----END PGP SIGNATURE-----