[Serusers] Nat Helper + Media Proxy

[Greger V. Teigre]

nat_uac_test("19") will add an extra test where srcip:port is compared to contactip:port. If they differ, you can add force proxing as stun failed. (BTW, STUN clients SHOULD not try to replace contact and sdp when symmetric nat is detected, but many uacs do.)
Also, investigate active media, force_nated_sdp("3"). Many gateways support active media and some user agents.
g-)
  ----- Original Message ----- 
  From: Darren Sessions 
  To: brettlist at nemeroff.com 
  Cc: serusers at lists.iptel.org 
  Sent: Tuesday, March 14, 2006 3:58 PM
  Subject: Re: [Serusers] Nat Helper + Media Proxy


  I appreciate the insight, but let me clarify.

  Today, we use stun + nathelper with over 6000 customers - and it works well. We have a relatively small percentage of customers that have, thus far, unsolvable issues (mostly symmetric nats). Having implemented the ser media proxy software about 2 years ago, I am familiar with the general principle behind the module (although the media proxy of today is far more advanced). Mediaproxy seems to work wonders for our customers that have problems and/or just don't work with our primary stun + nathelper methods.

  What I meant to explain is that I wanted to utilize each of the modules specific functionality in a staged approach on one server. One of our primary concerns is local bandwidth consumption (we're a small outfit). To keep that to a minimum, we don't want to just use media proxy instead of nathelper to solve our problems. We'd prefer to use nathelper where it fits with the 90%+ of the customer base, and use mediaproxy with the rest , based on an analysis done on the call (e.g. all calls routing through one server and based on results from the previously mentioned nat testing functions (or something similar), would process a particular call with the appropriate module (nathelper or mediaproxy) and functions).

  I hope I've better explained the situation.

  Thanks again for your comments,

   - Darren



  Brett N wrote: 
Look, think of it this way..

When a NATTED phone makes a sip call, it places it's NATTED address in the
header information of the call.. Making the far end phone send audio to
this UNREACHABLE ip address.. Nathelper will assist you in REWRITING the
SIP message such that you REMOVE the private addresses your NATTED phone
has put in the SIP message and instead places the actual IP/port your
phone uses to talk to SER with into the message. This in itself for most
people will allow a natted phone to make phone calls..

Now if you are going from nat to nat or having trouble  with one way calls
or the like, or if you just want more control over the audio path, you can
try mediaproxy. Chances are that you'll either need something like
nathelper to fix the SIP messaging OR  your proxy will need to be able to
ping and be ping the proxy. OR your media proxy module will need to be
able to do this rewriting for you.

Hope that helps.
-Brett

On Mon, March 13, 2006 10:44 am, Darren Sessions wrote:
  I've been reading the docs on nathelper and mediaproxy and am curious
about the possibility of implementing both modules/functionalities on
the same proxy (with the dispatcher and media proxy scripts running
on separate boxes).

The scenario would be to use either nathelper functionality or
mediaproxy functionality based on results from something like
client_nat_test, nat_uac_test, or another function like these. This
would prevent unnecessary local bandwidth consumption by providing
the correct nat transversal mechanism.

After extensive googling, I still haven't been able to find a working/
semi-working example on this type of combination.

Does anyone have any good pointers, example configs / basic configs,
or ideas?

Thanks in advance,

  - Darren

CALL
    |
    |->  Analysis
		|
		|-> NATHELPER
                or
                 |-> MEDIAPROXY


_______________________________________________
Serusers mailing list
serusers at lists.iptel.org
http://lists.iptel.org/mailman/listinfo/serusers


    


  

------------------------------------------------------------------------------


  _______________________________________________
  Serusers mailing list
  serusers at lists.iptel.org
  http://lists.iptel.org/mailman/listinfo/serusers
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-users/attachments/20060315/fad86be2/attachment.htm>