[asterisk-users] Question about PLC of Asterisk

[nakaji at 02.246.ne.jp]

Hi,I want to know how to do to work PLC of Asterisk.
Anyone plz help me.

PLC (Packet Loss Concealment) is included in Asterisk,I read at voip-info.org or release note.
And I see in codecs.conf, "genelicplc" setting.

So I put codecs.conf in '/etc/asterisk' ,and wrote "genericplc => true".
And I worked Asterisk and tested.

I think PLC like this. 
When I send 3 packet (1,2,3), and caused loss (if No.2 is lossed),
then receive-packet after PLC should be same number 3 packet(1,2,3).
No.2 is new one. I don't know 2 is same sound to old 2,or is zero level sound.
But same number packets should be resend from Asterisk to receiver.

But when I send 3 packet, received-packet is 2 packet(1,3).
No.2 has lossed.
No interpolation has been done.

So I can't understand how to do to work PLC of Asterisk.

Please help me.

I tested Asterisk 1.4.* and 1.6.0.
Use uLaw to send and receive on SIP/RTP.
And caused 5-20% loss from send-packet and through Asterisk ,I checked receive-packet.
 
Is there another things to do without "to put codecs.conf in /etc/asterisk" ?
Or Asterisk has no PLC on uLaw ?