diff -up iaxclient-2.1beta3/lib/ringbuffer.c.arm iaxclient-2.1beta3/lib/ringbuffer.c
--- iaxclient-2.1beta3/lib/ringbuffer.c.arm	2013-07-15 22:07:08.478680792 -0400
+++ iaxclient-2.1beta3/lib/ringbuffer.c	2013-07-15 22:07:36.449681212 -0400
@@ -104,6 +104,10 @@
 #      define rb_FullMemoryBarrier()  asm volatile("sync":::"memory")
 #      define rb_ReadMemoryBarrier()  asm volatile("sync":::"memory")
 #      define rb_WriteMemoryBarrier() asm volatile("sync":::"memory")
+#   elif defined( __arm__ )
+#	define rb_FullMemoryBarrier()  asm volatile("dmb":::"memory")
+#	define rb_ReadMemoryBarrier()  asm volatile("dmb":::"memory")
+#	define rb_WriteMemoryBarrier() asm volatile("dmb":::"memory")
 #   elif defined( __SSE2__ )
 #      define rb_FullMemoryBarrier()  asm volatile("mfence":::"memory")
 #      define rb_ReadMemoryBarrier()  asm volatile("lfence":::"memory")