I am trying to enable modem on ANDROID ICS 4.o.3

I am able to get PPP interface in netcfg with IP
If I launch the ping www.google.com from terminal I am able to get continuous resoponse
but if I launch the browser the ping is giving the error

ping: sendmsg: No buffer space available

and browser also not loading more than one page for the second page it is keep on loading
and at the end it is saying a network has occurred
ping: sendmsg: No buffer space available
and some times browser is trying for long time and it is giving a pop-up window saying A network error occured

In ppp_async.c OBUFFSIZE is 4096 I tried with 10240 also but it didn't worked

and I tried echo 83886080 > /proc/sys/net/core/wmem_max then also same problem

the tcp buffer sizes in init.rc are

setprop net.tcp.buffersize.default 4096,87380,110208,4096,16384,

110208
    setprop net.tcp.buffersize.wifi    524288,1048576,2097152,262144,524288,1048576
    setprop net.tcp.buffersize.lte     524288,1048576,2097152,262144,524288,1048576
    setprop net.tcp.buffersize.umts    4094,87380,110208,4096,16384,110208
    setprop net.tcp.buffersize.hspa    4094,87380,262144,4096,16384,262144
    setprop net.tcp.buffersize.edge    4093,26280,35040,4096,16384,35040
    setprop net.tcp.buffersize.gprs    4092,8760,11680,4096,8760,11680

* My board is having 512MB RAM is it ok for ICS or it can be cause for this problem

Did anybody faced this problem any suggestions to debug this

Thanks & Regards

O S L Reddy