diff --git a/extend.c b/extend.c
index 9c34c56..5ce77ad 100644
--- a/extend.c
+++ b/extend.c
@@ -212,6 +212,12 @@ static bool check_proto_tcp(int proto, char *buffer, ssize_t n)
 }
 
 
+static bool check_round(int nr[2], int r)
+{
+    return (!nr[1] && r <= 1) || (r >= nr[0] && r <= nr[1]);
+}
+
+
 static int on_trigger(int type, struct poolhd *pool, struct eval *val)
 {
     int m = val->pair->attempt + 1;
@@ -435,31 +441,35 @@ ssize_t tcp_send_hook(struct eval *remote,
         char *buffer, size_t bfsize, ssize_t n)
 {
     ssize_t sn = -1;
+    int skip = remote->flag != FLAG_CONN; 
     
-    if (remote->flag != FLAG_CONN 
-            || remote->pair->round_count > params.repeats) {
+    if (!skip) {
+        struct eval *client = remote->pair;
+    
+        if (client->recv_count == n 
+                && setup_conn(client, buffer, n) < 0) {
+            return -1;
+        }
+        int m = client->attempt, r = client->round_count;
+        if (!check_round(params.dp[m].rounds, r)) {
+            skip = 1;
+        }
+        else {
+            LOG((m ? LOG_S : LOG_L), "desync TCP, m=%d, r=%d\n", m, r);
+            
+            ssize_t offset = remote->pair->round_sent;
+            if (!offset && remote->round_count) offset = -1;
+            
+            sn = desync(remote->fd, buffer, bfsize, n,
+                offset, (struct sockaddr *)&remote->in6, m);
+        }
+    }
+    if (skip) {
         sn = send(remote->fd, buffer, n, 0);
         if (sn < 0 && get_e() == EAGAIN) {
             return 0;
         }
-        remote->pair->round_sent += sn;
-        return sn;
     }
-    struct eval *client = remote->pair;
-    
-    if (client->recv_count == n 
-            && setup_conn(client, buffer, n) < 0) {
-        return -1;
-    }
-    int m = client->attempt;
-    LOG((m ? LOG_S : LOG_L), "desync TCP, m=%d\n", m);
-    
-    ssize_t offset = client->round_sent;
-    if (!offset && remote->round_count) offset = -1;
-    
-    sn = desync(remote->fd, buffer, bfsize, n,
-        offset, (struct sockaddr *)&remote->in6, m);
-        
     remote->pair->round_sent += sn;
     return sn;
 }
@@ -497,7 +507,8 @@ ssize_t tcp_recv_hook(struct poolhd *pool, struct eval *val,
         val->pair->round_sent = 0;
     }
     if (val->flag == FLAG_CONN
-            && val->round_count >= params.repeats
+            && check_round(
+                params.dp[val->pair->attempt].rounds, val->round_count)
             && cancel_setup(val)) {
         return -1;
     }
@@ -510,10 +521,7 @@ ssize_t udp_hook(struct eval *val,
 {
     struct eval *pair = val->pair->pair;
     
-    if (pair->round_count > params.repeats) {
-        return send(val->fd, buffer, n, 0);
-    }
-    int m = val->attempt;
+    int m = pair->attempt, r = pair->round_count;
     if (!m) {
         for (; m < params.dp_count; m++) {
             struct desync_params *dp = &params.dp[m];
@@ -526,9 +534,12 @@ ssize_t udp_hook(struct eval *val,
         if (m >= params.dp_count) {
             return -1;
         }
-        val->attempt = m;
+        pair->attempt = m;
     }
-    LOG(LOG_S, "desync UDP, m=%d\n", m);
+    if (!check_round(params.dp[m].rounds, r)) {
+        return send(val->fd, buffer, n, 0);
+    }
+    LOG(LOG_S, "desync UDP, m=%d, r=%d\n", m, r);
     return desync_udp(val->fd, buffer, bfsize, n, &dst->sa, m);
 }
 
diff --git a/main.c b/main.c
index 3a8bb90..f38db60 100644
--- a/main.c
+++ b/main.c
@@ -54,7 +54,6 @@ struct params params = {
     .laddr = {
         .sin6_family = AF_INET
     },
-    .repeats = 1,
     .debug = 0,
     .auto_level = AUTO_NOBUFF
 };
@@ -81,13 +80,13 @@ const char help_text[] = {
     "                              Detect: torst,redirect,ssl_err,none\n"
     "    -L, --auto-mode <0|1>     1 - handle trigger after several packets\n"
     "    -u, --cache-ttl <sec>     Lifetime of cached desync params for IP\n"
-    "    -R, --repeats <num>       Number of requests to which desync will be applied\n"
     #ifdef TIMEOUT_SUPPORT
     "    -T, --timeout <sec>       Timeout waiting for response, after which trigger auto\n"
     #endif
     "    -K, --proto <t,h,u>       Protocol whitelist: tls,http,udp\n"
     "    -H, --hosts <file|:str>   Hosts whitelist, filename or :string\n"
     "    -V, --pf <port[-portr]>   Ports range whitelist\n"
+    "    -R, --round <num[-numr>   Number of request to which desync will be applied\n"
     "    -s, --split <pos_t>       Position format: offset[:repeats:skip][+flag1[flag2]]\n"
     "                              Flags: +s - SNI offset, +h - HTTP host offset\n"
     "                              Additional flags: +e - end, +m - middle, +r - random\n"
@@ -136,7 +135,6 @@ const struct option options[] = {
     #endif
     {"auto",          1, 0, 'A'},
     {"auto-mode",     1, 0, 'L'},
-    {"repeats",       1, 0, 'R'},
     {"cache-ttl",     1, 0, 'u'},
     #ifdef TIMEOUT_SUPPORT
     {"timeout",       1, 0, 'T'},
@@ -144,6 +142,7 @@ const struct option options[] = {
     {"proto",         1, 0, 'K'},
     {"hosts",         1, 0, 'H'},
     {"pf",            1, 0, 'V'},
+    {"repeats",       1, 0, 'R'},
     {"split",         1, 0, 's'},
     {"disorder",      1, 0, 'd'},
     {"oob",           1, 0, 'o'},
@@ -620,14 +619,6 @@ int main(int argc, char **argv)
                 params.auto_level = val;
             break;
             
-        case 'R':
-            val = strtol(optarg, &end, 0);
-            if (val < 1 || val > INT_MAX || *end)
-                invalid = 1;
-            else
-                params.repeats = val;
-            break;
-            
         case 'A':
             if (!(dp->hosts || dp->proto || dp->pf[0] || dp->detect)) {
                 all_limited = 0;
@@ -881,6 +872,24 @@ int main(int argc, char **argv)
             }
             break;
             
+        case 'R':
+            val = strtol(optarg, &end, 0);
+            if (val <= 0 || val > INT_MAX)
+                invalid = 1;
+            else {
+                dp->rounds[0] = val;
+                if (*end == '-') {
+                    val = strtol(end + 1, &end, 0);
+                    if (val <= 0 || val > INT_MAX)
+                        invalid = 1;
+                }
+                if (*end)
+                    invalid = 1;
+                else
+                    dp->rounds[1] = val;
+            }
+            break;
+            
         case 'g':
             val = strtol(optarg, &end, 0);
             if (val <= 0 || val > 255 || *end)
diff --git a/params.h b/params.h
index 1fdade9..c30d857 100644
--- a/params.h
+++ b/params.h
@@ -89,6 +89,7 @@ struct desync_params {
     int detect;
     struct mphdr *hosts;
     uint16_t pf[2];
+    int rounds[2];
     
     char *file_ptr;
     ssize_t file_size;
@@ -118,8 +119,6 @@ struct params {
     struct mphdr *mempool;
     
     char *protect_path;
-    
-    int repeats;
 };
 
 extern struct params params;