Problem with bidirectional audio

Hello,

Im new to the Asterisk World. I have set up asterisk successfully on a machine running Linux . And i also installed the X-Lite softphone on the same machine.
Then for test purposes i just installed the X-Lite softphone on a Windows machine which i connected to my Linux machine running Asterisk.

For testing, i made a call from the softphone on the windows machine to the softphone on the Linux machine, and the call went through successfully.
Also, im able to call the softphone on the Windows machine using the softphone on Linux.

The problem is whenever i make a call, i can hear the voice of the person ive called, but that person cannot hear me. This happens irrespective of whether i place the call from the Linux or Windows machine.

Below is a snippet of the code i use in extensions.conf

[testcontext] exten => 1234,1,Dial(SIP/ivan) exten => 4321,1,Dial(SIP/test)

Ive defined the users in sip.conf as follows :

[code][ivan]
type=friend
username=ivan
secret=pwd_ivan
host=dynamic
context=testcontext

[test]
type=friend
username=test
secret=pwd_test
host=dynamic
context=testcontext[/code]

What could be the problem ?

Please help.
Thank You.

One way audio is almost always the result of a firewall issue. What is the topography of the network where you asterisk server and softphones are?

Thanks for the reply Bruce . Well, i think i have checked that there is no firewall running on both the computers . Also, i think the fact that when A calls B, then A can hear B but not vice versa (where A is either Windows or Linux),shows that there is no firewall blocking the voice transfer.
As for the network topology, i have directly connected the two computers using a cable whose one end is plugged into the ethernet port of the windows machine and the other end plugged into the ethernet port of the Linux machine.

What else could be going wrong here ?

Thanks.

Are you sure that IPTables is not running on the asterisk server?

How many NICs do you have one both computers? Is this cable the only network your computers have?

@Bruce
Thanks for the reply Bruce . Well, i havent set up iptables on the Linux machine , and im the only one who uses it . It has the Fedora 10 distro running on it.
Is there a way to check if some important ports required by SIP or RTP are being blocked ?

@Wowks
Thanks for the reply Wowks . There is a single NIC in each computer. Also, since ive set this up at my home so this cable is the only network the two computers have.

In many cases, IPTables are installed by default and you don’t even know it. So even if you haven’t set them up, they might still be running.

An easy way to check is to run the “setup” command on your linux box and look at the firewall section. If they are running, you should either set them up properly of disable.