Index: channels/chan_ooh323.c
===================================================================
--- channels/chan_ooh323.c	(revision 1112)
+++ channels/chan_ooh323.c	(working copy)
@@ -887,6 +887,9 @@
 	static struct ast_frame null_frame = { AST_FRAME_NULL, };
 	struct ooh323_pvt *p = ast->tech_pvt;
 
+	if (!p)
+		return &null_frame;
+
 	ast_mutex_lock(&p->lock);
 	if (p->rtp)
 		fr = ooh323_rtp_read(ast, p);