diff --git a/include/utils/sequencer.h b/include/com/sequencer.h
similarity index 94%
rename from include/utils/sequencer.h
rename to include/com/sequencer.h
index 3f4ac6c..8e15918 100644
--- a/include/utils/sequencer.h
+++ b/include/com/sequencer.h
@@ -1,7 +1,7 @@
 /*!
- * \file utils/sequencer.h
+ * \file com/sequencer.h
  * \brief
- *      A terminal-like device communication automation tool
+ *      A script based automation tool for send/receive communications
  *
  * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
  *
@@ -28,8 +28,8 @@
  * </dd></dl>
  */
 
-#ifndef TBX_UTILS_SEQUENCER_H_
-#define TBX_UTILS_SEQUENCER_H_
+#ifndef TBX_COM_SEQUENCER_H_
+#define TBX_COM_SEQUENCER_H_
 
 
 #include <core/core.h>
@@ -147,14 +147,19 @@ class sequencer {
             size_t value;   //!< Used by \c GOTO to indicate the next sequencer's step.
         };
 
+        //! A no_action action_t
         static constexpr action_t no_action  = {action_t::NO, 0};
+        //! A next action_t
         static constexpr action_t next       = {action_t::NEXT, 0};
-
+        //! A goto action_t template
         template <size_t GOTO>
         static constexpr action_t go_to      = {action_t::GOTO, static_cast<size_t>(GOTO)};
 
+        //! An exit ok action_t
         static constexpr action_t exit_ok    = {action_t::EXIT, 0};
+        //! An exit error action_t
         static constexpr action_t exit_error = {action_t::EXIT, static_cast<size_t>(-1)};
+        //! A generic exit action_t template
         template <size_t Status>
         static constexpr action_t exit       = {action_t::EXIT, static_cast<size_t>(Status)};
 
@@ -421,6 +426,8 @@ class sequencer {
            clock_t mark = clock_();
 
            seq_status_t status{seq_status_t::CONTINUE}; do {
+               if (step >= Steps)
+                   return exit_error.value;
                const record_t& record = script[step];   // get reference ot current line
 
                if (step != p_step) {                    // renew time marker in each step
@@ -452,7 +459,7 @@ class sequencer {
                                    std::tie(step, status) = action_ (script, s);
                                    break;
                                }
-                           } while (script[++s].control == control_t::OR_EXPECT);
+                           } while ((++s < Steps) && (script[s].control == control_t::OR_EXPECT));
                        }
                        if (record.timeout && (clock_() - mark) >= record.timeout)
                            return exit_error.value;
@@ -468,7 +475,7 @@ class sequencer {
                                    std::tie(step, status) = action_ (script, s);
                                    break;
                                }
-                           } while (script[++s].control == control_t::OR_DETECT);
+                           } while ((++s < Steps) && (script[s].control == control_t::OR_DETECT));
                        }
                        if (record.timeout && (clock_() - mark) >= record.timeout)
                            return exit_error.value;
@@ -484,4 +491,4 @@ class sequencer {
 
 
 }
-#endif /* TBX_UTILS_SEQUENCER_H_ */
+#endif /* TBX_COM_SEQUENCER_H_ */
diff --git a/include/drv/BG95_base.h b/include/drv/ATmodem.h
similarity index 76%
rename from include/drv/BG95_base.h
rename to include/drv/ATmodem.h
index f29400a..5c3d2f1 100644
--- a/include/drv/BG95_base.h
+++ b/include/drv/ATmodem.h
@@ -1,7 +1,7 @@
 /*!
- * \file cont/BG95_base.h
+ * \file drv/ATmodem.h
  * \brief
- *      BG95 driver functionality as CRTP base class
+ *      ATmodem driver functionality as CRTP base class
  *
  * \copyright Copyright (C) 2021 Christos Choutouridis <christos@choutouridis.net>
  *
@@ -28,8 +28,8 @@
  * </dd></dl>
  */
 
-#ifndef TBX_DRV_BG95_base_H_
-#define TBX_DRV_BG95_base_H_
+#ifndef TBX_DRV_ATmodem_H_
+#define TBX_DRV_ATmodem_H_
 
 #define __cplusplus 201703L
 
@@ -37,7 +37,7 @@
 #include <core/crtp.h>
 #include <cont/equeue.h>
 #include <cont/range.h>
-#include <utils/sequencer.h>
+#include <com/sequencer.h>
 
 #include <cstring>
 #include <cstdlib>
@@ -63,12 +63,12 @@ namespace tbx {
  * \tparam Delimiter
  */
 template<typename Impl_t, size_t N, char Delimiter ='\n'>
-class BG95_base
-        : public sequencer<BG95_base<Impl_t, N, Delimiter>, char, N>{
+class ATmodem
+        : public sequencer<ATmodem<Impl_t, N, Delimiter>, char, N>{
         _CRTP_IMPL(Impl_t);
 
         // local type dispatch
-        using base_type     = sequencer<BG95_base, char, N>;
+        using base_type     = sequencer<ATmodem, char, N>;
 
     //! \name Public types
     //! @{
@@ -106,10 +106,10 @@ class BG95_base
     //!@{
     protected:
         //!< \brief A default constructor from derived only
-        BG95_base() = default;
-        ~BG95_base () = default;                            //!< \brief Allow destructor from derived only
-        BG95_base(const BG95_base&) = delete;               //!< No copies
-        BG95_base& operator= (const BG95_base&) = delete;   //!< No copy assignments
+        ATmodem() noexcept = default;
+        ~ATmodem () = default;                          //!< \brief Allow destructor from derived only
+        ATmodem(const ATmodem&) = delete;               //!< No copies
+        ATmodem& operator= (const ATmodem&) = delete;   //!< No copy assignments
     //!@}
 
     //! \name Sequencer interface requirements
@@ -139,6 +139,28 @@ class BG95_base
     //! \name Private functionality
     //! @{
     private:
+
+        template <typename... Ts>
+        struct typelist {
+            using type = typelist;   //!< act as identity
+        };
+
+        template <typename L>
+        struct front_impl {
+            using type = void;
+        };
+
+        template <typename Head, typename... Tail>
+        struct front_impl<typelist<Head, Tail...>> {
+            using type = Head;
+        };
+
+        //! Return the first element in \c meta::typelist \c List.
+        //!
+        //! Complexity \f$ O(1) \f$.
+        template <typename List>
+        using front = typename front_impl<List>::type;
+
         template<typename T>
         void extract (const char* str, T* value) {
             static_assert (
@@ -154,6 +176,9 @@ class BG95_base
                 std::strcpy(value, str);
             }
         }
+        void extract (const char* str, void* value) {
+            (void)*str; (void)value;
+        }
 
         template <char Marker = '%'>
         std::pair<size_t, bool> parse (const char* expected, const string_view buffer, char* token) {
@@ -253,29 +278,45 @@ class BG95_base
          *    if (done && status == 1)
          *       std::cout << "Connected to home network\n"
          * \endcode
+         * element_type (&arr)[N]
          */
-        template <typename T, char Marker = '%'>
-        bool command (const string_view cmd, const string_view expected, T* value, clock_t timeout =0) {
-            char buffer[N];
-            char token[N];
+        template<char Marker = '%', typename ...Ts>
+        bool command (const string_view cmd, const string_view expected, clock_t timeout, Ts* ...values) {
+
+            constexpr size_t Nr = sizeof...(Ts);
+            front<typelist<Ts...>>* vargs[Nr] = {values...};
+
+            if constexpr (Nr == 0) { (void)vargs; }
+
+            char buffer[N], token[N];
+            size_t v =0;
 
-            transmit(cmd.data());                       // send command
+            transmit(cmd.data());                           // send command
 
             for (auto ex = expected.begin() ; ex != expected.end() ;  ) {
-                clock_t mark = clock();                 // load the answer with timeout
+                clock_t mark = clock();                     // load the answer with timeout
                 size_t sz =0;
-                do {
-                    sz = receive(buffer);
-                	if ((timeout != 0 )&& ((clock() - mark) >= timeout))
-                	    return false;
-                } while (!sz);
-
-                for (size_t i=0 ; i<sz ; ) {            // parse buffer based on expected
-                    auto [step, marker] = parse<Marker> (ex++, {&buffer[i], sz-i}, token);
-                    if (!step)      return false;
-                    if (marker)     extract(token, value);
-                    i += step;
-                }
+                bool redo = false; do {
+                    do {
+                        sz = receive(buffer);
+                        if ((timeout != 0 )&& ((clock() - mark) >= timeout))
+                            return false;
+                    } while (!sz);
+
+                    redo = false;                           // have faith to parse successfully
+                    for (size_t i=0 ; i<sz ; ) {            // parse buffer based on expected
+                        auto [step, marker] = parse<Marker> (ex++, {&buffer[i], sz-i}, token);
+                        if (!step) {
+                            redo = true;                    // fail to parse, reload and retry
+                            break;
+                        }
+                        if constexpr (Nr > 0) {
+                            if (marker && v< Nr)
+                                extract(token, vargs[v++]);
+                        }
+                        i += step;
+                    }
+                } while (redo);
             }
             return true;
         }
@@ -324,4 +365,4 @@ class BG95_base
 
 } // namespace tbx;
 
-#endif /* TBX_DRV_BG95_base_H_ */
+#endif /* #ifndef TBX_DRV_ATmodem_H_ */
diff --git a/test/tests/BG95_base.cpp b/test/tests/ATmodem.cpp
similarity index 68%
rename from test/tests/BG95_base.cpp
rename to test/tests/ATmodem.cpp
index f0f0574..3436fd2 100644
--- a/test/tests/BG95_base.cpp
+++ b/test/tests/ATmodem.cpp
@@ -1,5 +1,5 @@
 /*!
- * \file sequencer.cpp
+ * \file ATmodem.cpp
  *
  * \copyright Copyright (C) 2020 Christos Choutouridis <christos@choutouridis.net>
  *
@@ -26,15 +26,14 @@
  * </dd></dl>
  *
  */
-#include <drv/BG95_base.h>
+#include <drv/ATmodem.h>
 #include <gtest/gtest.h>
+
 #include <cont/equeue.h>
-//#include <map>
 
-//#include <iostream>
 #include <cstring>
 #include <utility>
-
+#include <type_traits>
 #ifndef WIN_TRHEADS
 #include <mutex>
 #include <thread>
@@ -43,17 +42,18 @@
 #include <mingw.mutex.h>
 #endif
 
-namespace test_bg95_base {
+namespace test_ATmodem {
    using namespace tbx;
 
-
+   // test settings
+   constexpr size_t Size  = 128;
+   using data_type        = char;
 
    // BG95 implementer mock
    template<size_t N>
-   class BG95 : public BG95_base<BG95<N>, N> {
-
-	   using Q = equeue<char, N, true>;
-	   using base_type = BG95_base<BG95<N>, N>;
+   class BG95 : public ATmodem<BG95<N>, N> {
+	   using base_type = ATmodem<BG95<N>, N>;
+	   using Queue     = equeue<typename base_type::value_type, N, true>;
 
        public:
            enum class event {
@@ -114,15 +114,13 @@ namespace test_bg95_base {
            }
 
            // data
-           Q rx_q{};
+           Queue rx_q{};
            std::atomic<size_t> lines{};
-       public:
-           using range_t = typename Q::range_t;
 
        public:
-           // BG95_base driver requirements
-           BG95() :
-               rx_q(Q::data_match::MATCH_PUSH, base_type::delimiter, [&](){
+           // ATmodem driver requirements
+           BG95() noexcept :
+               rx_q(Queue::data_match::MATCH_PUSH, base_type::delimiter, [&](){
                    lines.fetch_add(1, std::memory_order_acq_rel);
                }), lines(0) { }
 
@@ -146,7 +144,6 @@ namespace test_bg95_base {
                return nullpos - data;
            }
            size_t put (const char* data, size_t n) {
-               std::cerr << " ";
                const char* reply = cmd_responce (data);
                while (*reply)
                    rx_q << *reply++;
@@ -168,28 +165,43 @@ namespace test_bg95_base {
    void handler (const char* data, size_t n) {
        (void)*data;
        (void)n;
-//       std::cout << "* handler called\n";
        handler_flag = true;
    }
    void clear_flag () {
        handler_flag = false;
    }
+
+   TEST(TATmodem, traits) {
+       EXPECT_EQ ( std::is_default_constructible<BG95<Size>>::value, true);
+       EXPECT_EQ ( std::is_nothrow_default_constructible<BG95<Size>>::value, true);
+       EXPECT_EQ (!std::is_copy_constructible<BG95<Size>>::value, true);
+       EXPECT_EQ (!std::is_copy_assignable<BG95<Size>>::value, true);
+
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::value_type, data_type>), true);
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::pointer_type, data_type*>), true);
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::size_type, size_t>), true);
+       EXPECT_EQ ((std::is_same_v<BG95<Size>::string_view, std::basic_string_view<data_type>>), true);
+
+       BG95<Size> m;
+       EXPECT_EQ (m.size(), Size);
+   }
+
    /*
     * Test inetd in non blocking mode
     */
-   TEST(TBG95_base, inetd_non_blocking) {
-       BG95<256> modem;
-       char buffer[256];
+   TEST(TATmodem, inetd_non_blocking) {
+       BG95<Size> modem;
+       char buffer[Size];
 
-       const BG95<256>::inetd_handlers<2> async = {{
-           {"+QMTOPEN:", BG95<256>::starts_with, handler},
-           {"+QMT",      BG95<256>::starts_with, handler},
+       const BG95<Size>::inetd_handlers<2> async = {{
+           {"+QMTSTAT:", BG95<Size>::starts_with, handler},
+           {"+QMTRECV",  BG95<Size>::contains,    handler},
        }};
 
        clear_flag();
        modem.inetd(false, &async);
        EXPECT_EQ (handler_flag, false);
-       modem.async(BG95<256>::event::MQTT_DISCONNECT);
+       modem.async(BG95<Size>::event::MQTT_DISCONNECT);
        modem.inetd(false, &async);     // parse "\r\n"
        EXPECT_EQ (handler_flag, false);
        modem.inetd(false, &async);      // parse "+QMT*\r\n"  and dispatch to handler()
@@ -225,41 +237,37 @@ namespace test_bg95_base {
        EXPECT_EQ (modem.receive(buffer), 0UL);
    }
 
-//   TEST(TBG95_base, run) {
-//	   BG95<256> modem;
-//
-//	   using Control = BG95<256>::control_t;
-//	   using Action  = BG95<256>::action_t;
-//
-//	   const BG95<256>::inetd_handlers<2> async = {{
-//           {"+QMTOPEN:", BG95<256>::starts_with, handler},
-//           {"+QMT",      BG95<256>::starts_with, handler},
-//	   }};
-//       const BG95<256>::script_t<7> script = {{
-//           {Control::NOP,      "",          BG95<256>::nil,         BG95<256>::nil,  {Action::GOTO, 1},       1000},
-//           {Control::SEND,     "ATE0\r\n",  BG95<256>::nil,         BG95<256>::nil,  {Action::NEXT, 0},       0},
-//           {Control::EXPECT,   "OK\r\n",    BG95<256>::ends_with,   BG95<256>::nil,  {Action::NEXT, 0},       1000},
-//           {Control::OR_EXPECT,"ERROR",     BG95<256>::contains,    BG95<256>::nil,  {Action::EXIT_ERROR, 0}, 0},
-//           {Control::SEND,     "AT+CSQ\r\n",BG95<256>::nil,         BG95<256>::nil,  {Action::NEXT, 0},       0},
-//           {Control::EXPECT,   "OK\r\n",    BG95<256>::ends_with,   BG95<256>::nil,  {Action::EXIT_OK, 0},    1000},
-//           {Control::OR_EXPECT,"ERROR",     BG95<256>::contains,    BG95<256>::nil,  {Action::EXIT_ERROR, 0}, 0},
-//       }};
-//
-//       std::mutex m;
-//       m.lock();
-//       std::thread th1 ([&](){
-//           do
-//               modem.inetd(false, &async);
-//           while (!m.try_lock());
-//           m.unlock();
-//       });
-//       EXPECT_EQ (modem.run(script), true);
-//       m.unlock();    // stop and join inetd
-//       th1.join();
-//   }
-
-   TEST(TBG95_base, command) {
-       BG95<256> modem;
+   TEST(TATmodem, run) {
+       BG95<Size> modem;
+
+       using Control = BG95<Size>::control_t;
+
+       const BG95<Size>::script_t<4> script = {{
+           {Control::NOP,      "",          BG95<Size>::nil,         BG95<Size>::nil,  BG95<Size>::go_to<1>,   1000},
+           {Control::SEND,     "ATE0\r\n",  BG95<Size>::nil,         BG95<Size>::nil,  BG95<Size>::next,       0},
+           {Control::EXPECT,   "OK\r\n",    BG95<Size>::ends_with,   BG95<Size>::nil,  BG95<Size>::exit_ok,    1000},
+           {Control::OR_EXPECT,"ERROR",     BG95<Size>::contains,    BG95<Size>::nil,  BG95<Size>::exit_error, 0}
+       }};
+
+       std::mutex m;
+       m.lock();
+       std::thread th1 ([&](){
+           do
+               modem.inetd(false);
+           while (!m.try_lock());
+           m.unlock();
+       });
+       EXPECT_EQ (modem.run(script), BG95<Size>::exit_ok.value);
+       m.unlock();    // stop and join inetd
+       th1.join();
+   }
+
+   TEST(TATmodem, transmit) {
+
+   }
+
+   TEST(TATmodem, command) {
+       BG95<Size> modem;
 
        std::mutex m;
        m.lock();
@@ -269,13 +277,25 @@ namespace test_bg95_base {
            while (!m.try_lock());
            m.unlock();
        });
-       int status;
-       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n+CREG: 0,%\r\n\r\nOK\r\n", &status), true);
-       EXPECT_EQ (status, 5);
 
-       char substr[32];
-       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n%\r\n\r\nOK\r\n", substr), true);
-       EXPECT_EQ (strcmp("+CREG: 0,5", substr), 0);
+       EXPECT_EQ (modem.command("AT\r\n", "Something else", 1000), false);
+       EXPECT_EQ (modem.command("AT\r\n", "\r\nOK\r\n", 1000), true);
+
+       EXPECT_EQ (modem.command("AT\r\n", "%OK\r\n", 1000), true);
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "%OK\r\n", 1000), false);
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "%%%OK\r\n", 1000), true);
+
+       int status1, status2;
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n+CREG: 0,%\r\n\r\nOK\r\n", 1000, &status1), true);
+       EXPECT_EQ (status1, 5);
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n+CREG: %,%\r\n\r\nOK\r\n", 1000, &status1, &status2), true);
+       EXPECT_EQ (status1, 0);
+       EXPECT_EQ (status2, 5);
+
+       char substr1[32], substr2[32];
+       EXPECT_EQ (modem.command("AT+CREG?\r\n", "\r\n%\r\n\r\n%\r\n", 1000, substr1, substr2), true);
+       EXPECT_EQ (strcmp("+CREG: 0,5", substr1), 0);
+       EXPECT_EQ (strcmp("OK", substr2), 0);
 
        m.unlock();    // stop and join inetd
        th1.join();
diff --git a/test/tests/deque.cpp b/test/tests/deque.cpp
index bf7310a..9bc9516 100644
--- a/test/tests/deque.cpp
+++ b/test/tests/deque.cpp
@@ -62,6 +62,11 @@ namespace Tdeque {
     TEST(Tdeque, concept) {
         using deque_t = deque<int, 8>;
 
+        EXPECT_EQ ( std::is_default_constructible<deque_t>::value, true);
+        EXPECT_EQ ( std::is_nothrow_default_constructible<deque_t>::value, true);
+        EXPECT_EQ (!std::is_copy_constructible<deque_t>::value, true);
+        EXPECT_EQ (!std::is_copy_assignable<deque_t>::value, true);
+
         EXPECT_EQ (true, !is_span<deque_t>::value);
         EXPECT_EQ (true, !is_std_array<deque_t>::value);
         EXPECT_EQ (true, !std::is_array<deque_t>::value);
diff --git a/test/tests/sequencer.cpp b/test/tests/sequencer.cpp
index 8c92c54..8a5a03c 100644
--- a/test/tests/sequencer.cpp
+++ b/test/tests/sequencer.cpp
@@ -26,7 +26,7 @@
  * </dd></dl>
  *
  */
-#include <utils/sequencer.h>
+#include <com/sequencer.h>
 #include <gtest/gtest.h>
 
 #include <type_traits>
@@ -422,4 +422,30 @@ namespace test_sequencer {
        EXPECT_EQ (s.run(script4), Seq::exit_ok.value);
        EXPECT_EQ (handler_flag, true);
    }
+
+   TEST(Tsequencer, run_boundaries) {
+       Seq s;
+
+       const Seq::script_t<1> script1 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::next, 0},
+       }};
+       EXPECT_EQ (s.run(script1), Seq::exit_error.value);
+
+       const Seq::script_t<1> script2 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::go_to<1>, 0},
+       }};
+       EXPECT_EQ (s.run(script2), Seq::exit_error.value);
+
+       const Seq::script_t<1> script3 = {{
+           {Seq::control_t::NOP,  "", Seq::nil, Seq::nil, Seq::go_to<(size_t)-1>, 0},
+       }};
+       EXPECT_EQ (s.run(script3), Seq::exit_error.value);
+
+       const Seq::script_t<1> script4 = {{
+           {Seq::control_t::EXPECT,  "abc", Seq::nil, Seq::nil, Seq::next, 1000},
+       }};
+       s.clear_clock();
+       EXPECT_EQ (s.run(script4), Seq::exit_error.value);
+       EXPECT_GT (s.clock(), (clock_t)1000);
+   }
 }