diff --git a/conf/stellar.toml b/conf/stellar.toml
index 5cf9e2e..95956c1 100644
--- a/conf/stellar.toml
+++ b/conf/stellar.toml
@@ -52,4 +52,4 @@ evicted_session_filter_error_rate = 0.00001 # range: [0.0, 1.0]
 # TCP reassembly (Per direction)
 tcp_reassembly_enable = 1
 tcp_reassembly_max_timeout = 10000 # range: [1, 60000] (ms)
-tcp_reassembly_max_segments = 32   # 0: unlimited
\ No newline at end of file
+tcp_reassembly_max_segments = 32   # range: [2, 32]
\ No newline at end of file
diff --git a/src/session/session.h b/src/session/session.h
index 953ed65..8d96d05 100644
--- a/src/session/session.h
+++ b/src/session/session.h
@@ -99,6 +99,7 @@ struct tcp_half
 // the TCP protocol control block
 struct tcp_pcb
 {
+    uint8_t tcp_reassembly_enable;
     struct tcp_half c2s;
     struct tcp_half s2c;
 };
diff --git a/src/session/session_manager.cpp b/src/session/session_manager.cpp
index 82edb81..ee9bc4e 100644
--- a/src/session/session_manager.cpp
+++ b/src/session/session_manager.cpp
@@ -30,8 +30,7 @@ struct session_manager
 
 #define EVICTE_SESSION_BURST (RX_BURST_MAX)
 
-// TODO
-int check_options(const struct session_manager_options *opts)
+static int check_options(const struct session_manager_options *opts)
 {
      if (opts == NULL)
      {
@@ -168,17 +167,23 @@ static inline bool before(uint32_t seq1, uint32_t seq2)
 
 static void tcp_pcb_clean(struct tcp_pcb *pcb)
 {
-     if (pcb)
+     if (pcb && pcb->tcp_reassembly_enable)
      {
           tcp_reassembly_free(pcb->c2s.assembler);
           tcp_reassembly_free(pcb->s2c.assembler);
      }
 }
 
-static int tcp_pcb_init(struct tcp_pcb *pcb, uint64_t max_timeout, uint64_t max_seg_num)
+static int tcp_pcb_init(struct tcp_pcb *pcb, uint8_t tcp_reassembly_enable, uint64_t tcp_reassembly_max_timeout, uint64_t tcp_reassembly_max_segments)
 {
-     pcb->c2s.assembler = tcp_reassembly_new(max_timeout, max_seg_num);
-     pcb->s2c.assembler = tcp_reassembly_new(max_timeout, max_seg_num);
+     pcb->tcp_reassembly_enable = tcp_reassembly_enable;
+     if (pcb->tcp_reassembly_enable == 0)
+     {
+          return 0;
+     }
+
+     pcb->c2s.assembler = tcp_reassembly_new(tcp_reassembly_max_timeout, tcp_reassembly_max_segments);
+     pcb->s2c.assembler = tcp_reassembly_new(tcp_reassembly_max_timeout, tcp_reassembly_max_segments);
      if (pcb->c2s.assembler == NULL || pcb->s2c.assembler == NULL)
      {
           tcp_pcb_clean(pcb);
@@ -199,6 +204,18 @@ static void tcp_pcb_update(struct tcp_pcb *pcb, enum session_dir dir, const stru
      half->seq = tcp_hdr_get_seq(hdr);
      half->ack = tcp_hdr_get_ack(hdr);
 
+     if (pcb->tcp_reassembly_enable == 0)
+     {
+          if (tcp_layer->pld_len)
+          {
+               half->nr_seg_received++;
+               half->nr_seg_inorder++;
+               half->order.data = tcp_layer->pld_ptr;
+               half->order.len = tcp_layer->pld_len;
+          }
+          return;
+     }
+
      if (flags & TH_SYN)
      {
           tcp_reassembly_set_recv_next(half->assembler, half->seq + 1);
@@ -215,6 +232,7 @@ static void tcp_pcb_update(struct tcp_pcb *pcb, enum session_dir dir, const stru
      if (tcp_layer->pld_len)
      {
           half->nr_seg_received++;
+
           uint32_t rcv_nxt = tcp_reassembly_get_recv_next(half->assembler);
           if (half->seq == rcv_nxt)
           {
@@ -607,7 +625,7 @@ static struct session *session_manager_new_tcp_session(struct session_manager *m
      session_init(sess);
      session_set_id(sess, id_generator_alloc());
 
-     if (tcp_pcb_init(&sess->tcp_pcb, mgr->opts.tcp_reassembly_max_timeout, mgr->opts.tcp_reassembly_max_segments) == -1)
+     if (tcp_pcb_init(&sess->tcp_pcb, mgr->opts.tcp_reassembly_enable, mgr->opts.tcp_reassembly_max_timeout, mgr->opts.tcp_reassembly_max_segments) == -1)
      {
           assert(0);
           session_pool_push(mgr->sess_pool, sess);
diff --git a/src/session/session_manager.h b/src/session/session_manager.h
index e480dca..533a781 100644
--- a/src/session/session_manager.h
+++ b/src/session/session_manager.h
@@ -46,7 +46,7 @@ struct session_manager_options
     double evicted_session_filter_error_rate; // range: [0.0, 1.0]
 
     // TCP reassembly
-    uint8_t tcp_reassembly_enable;        // TODO not support
+    uint8_t tcp_reassembly_enable;
     uint32_t tcp_reassembly_max_timeout;  // range: [1, 60000] (ms)
     uint32_t tcp_reassembly_max_segments; // range: [2, 32]
 };