diff --git a/tuic/src/protocol/authenticate.rs b/tuic/src/protocol/authenticate.rs
index 988230d..ba016da 100644
--- a/tuic/src/protocol/authenticate.rs
+++ b/tuic/src/protocol/authenticate.rs
@@ -7,7 +7,7 @@ use super::Command;
 // +-------+
 #[derive(Clone, Debug)]
 pub struct Authenticate {
-    pub token: [u8; 8],
+    token: [u8; 8],
 }
 
 impl Authenticate {
@@ -16,6 +16,10 @@ impl Authenticate {
     pub const fn new(token: [u8; 8]) -> Self {
         Self { token }
     }
+
+    pub fn token(&self) -> &[u8; 8] {
+        &self.token
+    }
 }
 
 impl Command for Authenticate {
diff --git a/tuic/src/protocol/connect.rs b/tuic/src/protocol/connect.rs
index db57013..f32c6e7 100644
--- a/tuic/src/protocol/connect.rs
+++ b/tuic/src/protocol/connect.rs
@@ -7,7 +7,7 @@ use super::{Address, Command};
 // +----------+
 #[derive(Clone, Debug)]
 pub struct Connect {
-    pub addr: Address,
+    addr: Address,
 }
 
 impl Connect {
@@ -16,6 +16,10 @@ impl Connect {
     pub const fn new(addr: Address) -> Self {
         Self { addr }
     }
+
+    pub fn addr(&self) -> &Address {
+        &self.addr
+    }
 }
 
 impl Command for Connect {
diff --git a/tuic/src/protocol/dissociate.rs b/tuic/src/protocol/dissociate.rs
index d931d13..dc4dcf3 100644
--- a/tuic/src/protocol/dissociate.rs
+++ b/tuic/src/protocol/dissociate.rs
@@ -7,7 +7,7 @@ use super::Command;
 // +----------+
 #[derive(Clone, Debug)]
 pub struct Dissociate {
-    pub assoc_id: u16,
+    assoc_id: u16,
 }
 
 impl Dissociate {
@@ -16,6 +16,10 @@ impl Dissociate {
     pub const fn new(assoc_id: u16) -> Self {
         Self { assoc_id }
     }
+
+    pub fn assoc_id(&self) -> u16 {
+        self.assoc_id
+    }
 }
 
 impl Command for Dissociate {
diff --git a/tuic/src/protocol/packet.rs b/tuic/src/protocol/packet.rs
index 62a8219..c4d2a2b 100644
--- a/tuic/src/protocol/packet.rs
+++ b/tuic/src/protocol/packet.rs
@@ -1,18 +1,18 @@
 use super::{Address, Command};
 
-// +----------+--------+------------+---------+-----+----------+
-// | ASSOC_ID | PKT_ID | FRAG_TOTAL | FRAG_ID | LEN |   ADDR   |
-// +----------+--------+------------+---------+-----+----------+
-// |    2     |   2    |     1      |    1    |  2  | Variable |
-// +----------+--------+------------+---------+-----+----------+
+// +----------+--------+------------+---------+------+----------+
+// | ASSOC_ID | PKT_ID | FRAG_TOTAL | FRAG_ID | SIZE |   ADDR   |
+// +----------+--------+------------+---------+------+----------+
+// |    2     |   2    |     1      |    1    |  2   | Variable |
+// +----------+--------+------------+---------+------+----------+
 #[derive(Clone, Debug)]
 pub struct Packet {
-    pub assoc_id: u16,
-    pub pkt_id: u16,
-    pub frag_total: u8,
-    pub frag_id: u8,
-    pub len: u16,
-    pub addr: Address,
+    assoc_id: u16,
+    pkt_id: u16,
+    frag_total: u8,
+    frag_id: u8,
+    size: u16,
+    addr: Address,
 }
 
 impl Packet {
@@ -23,7 +23,7 @@ impl Packet {
         pkt_id: u16,
         frag_total: u8,
         frag_id: u8,
-        len: u16,
+        size: u16,
         addr: Address,
     ) -> Self {
         Self {
@@ -31,11 +31,35 @@ impl Packet {
             pkt_id,
             frag_total,
             frag_id,
-            len,
+            size,
             addr,
         }
     }
 
+    pub fn assoc_id(&self) -> u16 {
+        self.assoc_id
+    }
+
+    pub fn pkt_id(&self) -> u16 {
+        self.pkt_id
+    }
+
+    pub fn frag_total(&self) -> u8 {
+        self.frag_total
+    }
+
+    pub fn frag_id(&self) -> u8 {
+        self.frag_id
+    }
+
+    pub fn size(&self) -> u16 {
+        self.size
+    }
+
+    pub fn addr(&self) -> &Address {
+        &self.addr
+    }
+
     pub const fn len_without_addr() -> usize {
         2 + 2 + 1 + 1 + 2
     }