[SR-Users] Increasing MAX_RECV_BUFFER_SIZE

Dear Kamailio'ns I am working on Kamailio (V 4.0)+ Mediaproxy server (2.5.2) running on Ubuntu 12.04. I am experiencing some Latency, jitter, pixelled, choppy video errors in my set-up. So i wanted to increase buffer sizes of my kamailio server , Mediaproxy server and Ubuntu also. In that regards i have increased Shared memory value to 512 MB and Package memory value 16 MB. BUFFER SIZE value to 8 MB in *config.h* file, But where can i change the value for 'MAX_RECV_BUFFER_SIZE' of kamailio? And are there any settings to increase Buffer Size of Mediaproxy server ? Is this changes will affect on my issues ? PS: I even changed ubuntu settings also : net.core.rmem_max= 8388608 net.core.wmem_max= 8388608 (but these values reset to default values again when i restarted system.) Please help me in resolving this issues. Any help will appreciate. Regards, Ravi