[Asterisk-Users] Asterisk, Configuration of SDP in SIP messages

2004-05-13 Thread Alexander Simeonidis

Hello everybody,
I'm newto Asterisk and I'm trying to configure the SIP side.
I use Asterisk under the following configuration:
SIP Proxy  INTERNET  | NAT FIREWALL |  Asterisk  SIP Phone A
I'm trying to put a call from SIP Phone A through Asterisk to the SIP Proxy. I'm able to deliver messages to SIP Proxy. However, I have noticed that the port used to deliver the audio changes randomly. I would like to fix that to a specific range of ports so that I can tell to NAT Firewall to port forward these particalar ports to Asterisk. I have searched on documentation and the only thing that I found was how to change the SIP port but not the media port. Has anybody any ideas on how to solve that problem or where to look for a solution?
Regards,
Alex.Help STOP spam with the new MSN 8  and get 2 months FREE*
___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users


RE: [Asterisk-Users] Asterisk, Configuration of SDP in SIP messages

2004-05-13 Thread Leif Madsen
This is done in the rtp.conf file.  You specify the port range with a start
and end number.  By default the range is 1 through 2.

Leif.

 -Original Message-
 From: [EMAIL PROTECTED] [mailto:asterisk-users-
 [EMAIL PROTECTED] On Behalf Of Alexander Simeonidis
 Sent: Thursday, May 13, 2004 10:36 PM
 To: [EMAIL PROTECTED]
 Subject: [Asterisk-Users] Asterisk, Configuration of SDP in SIP messages
 
 Hello everybody,
 
 I'm new to Asterisk and I'm trying to configure the SIP side.
 
 I use Asterisk under the following configuration:
 
 SIP Proxy  INTERNET  | NAT FIREWALL |  Asterisk  SIP Phone
 A
 
 I'm trying to put a call from SIP Phone A through Asterisk to the SIP
 Proxy. I'm able to deliver messages to SIP Proxy. However, I have noticed
 that the port used to deliver the audio changes randomly. I would like to
 fix that to a specific range of ports so that I can tell to NAT Firewall
 to port forward these particalar ports to Asterisk. I have searched on
 documentation and the only thing that I found was how to change the SIP
 port but not the media port. Has anybody any ideas on how to solve that
 problem or where to look for a solution?
 
 Regards,
 
 Alex.
 
 
 
 
 Help STOP spam with the new MSN 8 http://g.msn.com/8HMAEN/2731??PS=47575
 and get 2 months FREE*
 ___ Asterisk-Users mailing
 list [EMAIL PROTECTED]
 http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or
 update options visit: http://lists.digium.com/mailman/listinfo/asterisk-
 users

___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
   http://lists.digium.com/mailman/listinfo/asterisk-users


Re: [Asterisk-Users] Asterisk, Configuration of SDP in SIP messages

2004-05-13 Thread Brian Cuthie
Alex,

The media ports are configured in rtp.conf.  Also, note that Asterisk 
sends RTP packets out the same ports it expects them to return on. This 
has the effect of creating a NAT mapping for that 5-tuple, as well as 
opening a hole in your firewall (naturally, YMMV depending on exactly 
what you're running for a firewall).

One interesting consequence of the way Asterisk works is that if you 
don't have anything behind the NAT/Firewall that's generating RTP 
packets (ie, no audio) no hole gets made and incoming packets will get 
rejected.  I recently ran into an interesting problem with two SIP 
phones trying to talk through Asterisk behind a (non-NAT) firewall. 

The problem was both phones were sending RTP to the Asterisk box but the 
firewall was blocking both RTP streams because Asterisk never sent any 
RTP out those ports. And the reason Asterisk hadn't sent RTP out those 
ports was because it was waiting for RTP from each of the two SIP 
phones. This was the classic chicken-and-egg scenario. 

I resolved it by opening up the firewall for the range of ports I had 
configured Asterisk to use for RTP.  A better solution would be fore 
Asterisk to always send a starter RTP packet so that it can ensure 
that the firewall opens up.

-brian

Alexander Simeonidis wrote:

Hello everybody,

I'm new to Asterisk and I'm trying to configure the SIP side.

I use Asterisk under the following configuration:

SIP Proxy  INTERNET  | NAT FIREWALL |  Asterisk  SIP 
Phone A

I'm trying to put a call from SIP Phone A through Asterisk to the SIP 
Proxy. I'm able to deliver messages to SIP Proxy. However, I have 
noticed that the port used to deliver the audio changes randomly. I 
would like to fix that to a specific range of ports so that I can tell 
to NAT Firewall to port forward these particalar ports to Asterisk. I 
have searched on documentation and the only thing that I found was how 
to change the SIP port but not the media port. Has anybody any ideas 
on how to solve that problem or where to look for a solution?

Regards,

Alex.


Help STOP spam with the new MSN 8 
http://g.msn.com/8HMAEN/2731??PS=47575 and get 2 months 
FREE*___ Asterisk-Users 
mailing list [EMAIL PROTECTED] 
http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE 
or update options visit: 
http://lists.digium.com/mailman/listinfo/asterisk-users 


___
Asterisk-Users mailing list
[EMAIL PROTECTED]
http://lists.digium.com/mailman/listinfo/asterisk-users
To UNSUBSCRIBE or update options visit:
  http://lists.digium.com/mailman/listinfo/asterisk-users