diff --git a/trunk/src/kernel/srs_kernel_rtc_rtcp.hpp b/trunk/src/kernel/srs_kernel_rtc_rtcp.hpp
index 8192d1894..4b215aee4 100644
--- a/trunk/src/kernel/srs_kernel_rtc_rtcp.hpp
+++ b/trunk/src/kernel/srs_kernel_rtc_rtcp.hpp
@@ -62,7 +62,7 @@ struct SrsRtcpHeader
 
 struct SrsSeqCompareLess {
     bool operator()(const uint16_t &lhs, const uint16_t &rhs) const {
-        return SnCompare(rhs, lhs);
+        return SrsSeqIsNewer(rhs, lhs);
     }
 };
 
diff --git a/trunk/src/kernel/srs_kernel_rtc_rtp.cpp b/trunk/src/kernel/srs_kernel_rtc_rtp.cpp
index ade0add7b..5a1a6ebbd 100644
--- a/trunk/src/kernel/srs_kernel_rtc_rtp.cpp
+++ b/trunk/src/kernel/srs_kernel_rtc_rtp.cpp
@@ -33,8 +33,8 @@ using namespace std;
 #include <srs_kernel_utility.hpp>
 #include <srs_kernel_flv.hpp>
 
-//sn comparison，if current_sn is more than last_sn，return true，else return false
-bool SnCompare(uint16_t current_sn, uint16_t last_sn) {
+//sn comparison，if current_sn is more(newer) than last_sn，return true，else return false
+bool SrsSeqIsNewer(uint16_t current_sn, uint16_t last_sn) {
    if(current_sn > last_sn) {
        //current_sn 65533   last_sn 5
        if(current_sn - last_sn > 0x8000) {
@@ -52,9 +52,9 @@ bool SnCompare(uint16_t current_sn, uint16_t last_sn) {
    }
 }
 
-bool SnRollback(uint16_t current_sn, uint16_t last_sn)
+bool SrsSeqIsRoolback(uint16_t current_sn, uint16_t last_sn)
 {
-    if(SnCompare(current_sn, last_sn)) {
+    if(SrsSeqIsNewer(current_sn, last_sn)) {
         if((last_sn > current_sn)) {
             return true;
         }
@@ -63,7 +63,7 @@ bool SnRollback(uint16_t current_sn, uint16_t last_sn)
 }
 
 // caculate the difference between sn. If current_sn is more then last_sn, return positive difference, else return negative difference.
-int32_t SnDiff(uint16_t current_sn, uint16_t last_sn) {
+int32_t SrsSeqDistance(uint16_t current_sn, uint16_t last_sn) {
     if(current_sn > last_sn) {
         //current_sn 65535   last_sn 0
         if(current_sn - last_sn > 0x8000) {
diff --git a/trunk/src/kernel/srs_kernel_rtc_rtp.hpp b/trunk/src/kernel/srs_kernel_rtc_rtp.hpp
index d2a74a039..b84a5531c 100644
--- a/trunk/src/kernel/srs_kernel_rtc_rtp.hpp
+++ b/trunk/src/kernel/srs_kernel_rtc_rtp.hpp
@@ -59,9 +59,9 @@ class SrsRtpFUAPayload2;
 class SrsSharedPtrMessage;
 
 // TODO: FIXME: Merge with srs_rtp_seq_distance
-bool SnCompare(uint16_t current_sn, uint16_t last_sn);
-bool SnRollback(uint16_t current_sn, uint16_t last_sn);
-int32_t SnDiff(uint16_t current_sn, uint16_t last_sn);
+bool SrsSeqIsNewer(uint16_t current_sn, uint16_t last_sn);
+bool SrsSeqIsRoolback(uint16_t current_sn, uint16_t last_sn);
+int32_t SrsSeqDistance(uint16_t current_sn, uint16_t last_sn);
 
 class SrsRtpHeader
 {