Problem : I am using kcp, after sending few packets ikcp_send fails. data is not getting transmitted

sending  10bytes of data + 24 bytes kcp header  = 34 bytes 
             `// flash remain 
                    size = (int)(ptr - buffer);
                if (size > 0) {
	          ikcp_output(kcp, buffer, size);
                }`
         In the above code while data is sent correctly size is always 34 bytes. after some time  no data is send size is 0.
         so no ikcp_output happening.

            `int needsend = 0;
	if (segment->xmit == 0) {
		needsend = 1;
		segment->xmit++;
		segment->rto = kcp->rx_rto;
		segment->resendts = current + segment->rto + rtomin;
	}`

1. in correct case when data is getting send ,needsend is set to 1 in above condition.
2. in Error case needsend is always 0.

-> kcp create :
auto *ptr = ikcp_create(unique_id, reinterpret_cast<void *>(user_pointer)); ptr->output = callback_handler; ikcp_nodelay(ptr, 1, 10, 2, 1); // Turbo mode
-> using ikcp_send
int sent = ikcp_send(kcp_ptr, payload_buffer, payload_len); // kcp_ptr from ikcp_create call above ikcp_flush(kcp_ptr); ikcp_update(kcp_ptr, 10);