diff --git a/src/smf/gx-path.c b/src/smf/gx-path.c
index 96c9311a4..5ffeddb5f 100644
--- a/src/smf/gx-path.c
+++ b/src/smf/gx-path.c
@@ -28,9 +28,12 @@ struct sess_state {
 
     os0_t       peer_host;          /* Peer Host */
 
-#define MAX_CC_REQUEST_NUMBER 64
+#define NUM_CC_REQUEST_SLOT 4
     smf_sess_t *sess;
-    ogs_gtp_xact_t *xact[MAX_CC_REQUEST_NUMBER];
+    struct {
+        uint32_t cc_req_no;
+        ogs_gtp_xact_t *ptr;
+    } xact_data[NUM_CC_REQUEST_SLOT];
 
     uint32_t cc_request_type;
     uint32_t cc_request_number;
@@ -103,6 +106,7 @@ void smf_gx_send_ccr(smf_sess_t *sess, ogs_gtp_xact_t *xact,
     struct sockaddr_in sin;
     struct sockaddr_in6 sin6;
     uint32_t charging_id;
+    uint32_t req_slot;
 
     ogs_assert(sess);
 
@@ -191,11 +195,12 @@ void smf_gx_send_ccr(smf_sess_t *sess, ogs_gtp_xact_t *xact,
 
     ogs_debug("    CC Request Type[%d] Number[%d]",
         sess_data->cc_request_type, sess_data->cc_request_number);
-    ogs_assert(sess_data->cc_request_number <= MAX_CC_REQUEST_NUMBER);
 
     /* Update session state */
     sess_data->sess = sess;
-    sess_data->xact[sess_data->cc_request_number] = xact;
+    req_slot = sess_data->cc_request_number % NUM_CC_REQUEST_SLOT;
+    sess_data->xact_data[req_slot].ptr = xact;
+    sess_data->xact_data[req_slot].cc_req_no = sess_data->cc_request_number;
 
     /* Set Origin-Host & Origin-Realm */
     ret = fd_msg_add_origin(req, 0);
@@ -713,7 +718,7 @@ static void smf_gx_cca_cb(void *data, struct msg **msg)
     ogs_gtp_xact_t *xact = NULL;
     smf_sess_t *sess = NULL;
     ogs_diam_gx_message_t *gx_message = NULL;
-    uint32_t cc_request_number = 0;
+    uint32_t req_slot, cc_request_number = 0;
 
     ogs_debug("[Credit-Control-Answer]");
 
@@ -755,11 +760,13 @@ static void smf_gx_cca_cb(void *data, struct msg **msg)
     ret = fd_msg_avp_hdr(avp, &hdr);
     ogs_assert(ret == 0);
     cc_request_number = hdr->avp_value->i32;
+    req_slot = cc_request_number % NUM_CC_REQUEST_SLOT;
 
     ogs_debug("    CC-Request-Number[%d]", cc_request_number);
 
-    xact = sess_data->xact[cc_request_number];
+    xact = sess_data->xact_data[req_slot].ptr;
     sess = sess_data->sess;
+    ogs_assert(sess_data->xact_data[req_slot].cc_req_no == cc_request_number);
     ogs_assert(sess);
 
     gx_message = ogs_calloc(1, sizeof(ogs_diam_gx_message_t));
diff --git a/src/smf/gy-path.c b/src/smf/gy-path.c
index 0c2d56298..fce830994 100644
--- a/src/smf/gy-path.c
+++ b/src/smf/gy-path.c
@@ -29,12 +29,14 @@ struct sess_state {
 
     os0_t       peer_host;          /* Peer Host */
 
-#define MAX_CC_REQUEST_NUMBER 64
+#define NUM_CC_REQUEST_SLOT 4
+
     smf_sess_t *sess;
     struct {
+        uint32_t cc_req_no;
         bool pfcp;
         void *ptr; /* INITIAL: ogs_gtp_xact_t, UPDATE: ogs_pfcp_xact_t */
-    } xact_data[MAX_CC_REQUEST_NUMBER];
+    } xact_data[NUM_CC_REQUEST_SLOT];
     uint32_t cc_request_type;
     uint32_t cc_request_number;
 
@@ -567,7 +569,7 @@ void smf_gy_send_ccr(smf_sess_t *sess, void *xact,
     struct session *session = NULL;
     int new;
     const char *service_context_id = "32251@3gpp.org";
-    uint32_t timestamp;
+    uint32_t timestamp, req_slot;
 
     ogs_assert(xact);
     ogs_assert(sess);
@@ -657,15 +659,16 @@ void smf_gy_send_ccr(smf_sess_t *sess, void *xact,
 
     ogs_debug("    CC Request Type[%d] Number[%d]",
         sess_data->cc_request_type, sess_data->cc_request_number);
-    ogs_assert(sess_data->cc_request_number <= MAX_CC_REQUEST_NUMBER);
 
     /* Update session state */
     sess_data->sess = sess;
+    req_slot = sess_data->cc_request_number % NUM_CC_REQUEST_SLOT;
     if (cc_request_type == OGS_DIAM_GY_CC_REQUEST_TYPE_UPDATE_REQUEST)
-        sess_data->xact_data[sess_data->cc_request_number].pfcp = true;
+        sess_data->xact_data[req_slot].pfcp = true;
     else
-        sess_data->xact_data[sess_data->cc_request_number].pfcp = false;
-    sess_data->xact_data[sess_data->cc_request_number].ptr = xact;
+        sess_data->xact_data[req_slot].pfcp = false;
+    sess_data->xact_data[req_slot].cc_req_no = sess_data->cc_request_number;
+    sess_data->xact_data[req_slot].ptr = xact;
 
     /* Origin-Host & Origin-Realm */
     ret = fd_msg_add_origin(req, 0);
@@ -902,7 +905,7 @@ static void smf_gy_cca_cb(void *data, struct msg **msg)
     void *xact = NULL;
     smf_sess_t *sess = NULL;
     ogs_diam_gy_message_t *gy_message = NULL;
-    uint32_t cc_request_number = 0;
+    uint32_t req_slot, cc_request_number = 0;
 
     ogs_debug("[Gy][Credit-Control-Answer]");
 
@@ -944,11 +947,12 @@ static void smf_gy_cca_cb(void *data, struct msg **msg)
     ret = fd_msg_avp_hdr(avp, &hdr);
     ogs_assert(ret == 0);
     cc_request_number = hdr->avp_value->i32;
+    req_slot = cc_request_number % NUM_CC_REQUEST_SLOT;
 
     ogs_debug("    CC-Request-Number[%d]", cc_request_number);
 
-    xact = sess_data->xact_data[cc_request_number].ptr;
-    ogs_assert(xact);
+    xact = sess_data->xact_data[req_slot].ptr;
+    ogs_assert(sess_data->xact_data[req_slot].cc_req_no == cc_request_number);
     sess = sess_data->sess;
     ogs_assert(sess);
 
@@ -1106,10 +1110,10 @@ out:
         e->sess = sess;
         e->gy_message = gy_message;
         if (gy_message->cc_request_type == OGS_DIAM_GY_CC_REQUEST_TYPE_UPDATE_REQUEST) {
-            ogs_assert(sess_data->xact_data[sess_data->cc_request_number].pfcp == true);
+            ogs_assert(sess_data->xact_data[req_slot].pfcp == true);
             e->pfcp_xact = xact;
         } else {
-            ogs_assert(sess_data->xact_data[sess_data->cc_request_number].pfcp == false);
+            ogs_assert(sess_data->xact_data[req_slot].pfcp == false);
             e->gtp_xact = xact;
         }
         rv = ogs_queue_push(ogs_app()->queue, e);