how to test remote loop back in bluetooth

[samprat]

I have small in-house device running on linux platform with bluez libraries.

I have created a sco connection with Jaber Easygo device and everything works as expected. I mean I can play music on my linux machine using aplay and I can successfully hear on jabber. similarly I can record voice from jabber to linux machine using arecord.

Now I want to do testing using remote loopback, so that I send packets from Jabber to Linux machine and receive same packet back into Jabber.

After trying and spending days I couldn't able to crack it, so I am requesting you guys to please give some advice.

Below are the following things I tried.

1) Load kernel module snd-bt-sco 2) Ran btsco -v -r
o/p : successfully created the link and can play or record music . so far so good
Now for remote testing

i) open a terminal and type

hcitool cmd 0x06 0x002 0x02

o/p : sometimes
HCI Event : 0xff plen 7 CD 03 00 44 00 00 00

ii) In another terminal I use hcidump

hcidump -X sco -w test_remote_loop_log

iii) In another terminal I record so that packest goes from jabber to Linux box

arecord -B 1000000 _D plughw:Headset /home/my_place/test_remote_loop_1.wav

then I speak something on Jabber and close the above recording

iv) Using Wireshark and filter type "bthci_sco" all I have noticed is Rcvd SCO DATA has data in it ( which is obviously expected) example

0000 03 31 00 30 bf ff bb ff e4 etc

But Sent SCO DATA has no data in it example

0000 03 31 00 30 00 00 00 00 00 ..till end

Can some please guide me what I am doing wrong

thansk in advance