diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 358ba65ac6bd81780637dc4ab7ed1db256080c9b..8370af33f6fa0b639376f1dc04bb89b8c74a2274 100755
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -9617,10 +9617,10 @@ static int handle_request(struct sip_pvt *p, struct sip_request *req, struct soc
 	if (option_debug > 2)
 		ast_log(LOG_DEBUG, "**** Received %s (%d) - Command in SIP %s\n", sip_methods[p->method].text, sip_methods[p->method].id, cmd); 
 
-	if (p->icseq && (p->icseq > seqno)) {
+	if (p->icseq && (p->icseq > seqno) && req->method != SIP_ACK) {
 		ast_log(LOG_DEBUG, "Ignoring too old SIP packet packet %d (expecting >= %d)\n", seqno, p->icseq);
 		return -1;
-	} else if (p->icseq && (p->icseq == seqno) && (p->method != SIP_CANCEL|| ast_test_flag(p, SIP_ALREADYGONE))) {
+	} else if (p->icseq && (p->icseq == seqno) && req->method != SIP_ACK &&(p->method != SIP_CANCEL|| ast_test_flag(p, SIP_ALREADYGONE))) {
 		/* ignore means "don't do anything with it" but still have to 
 		   respond appropriately.  We do this if we receive a repeat of
 		   the last sequence number  */