diff --git a/net/adc_net_concepts.h b/net/adc_net_concepts.h
index 42b09bc..46c45a8 100644
--- a/net/adc_net_concepts.h
+++ b/net/adc_net_concepts.h
@@ -11,8 +11,41 @@ ABSTRACT DEVICE COMPONENTS LIBRARY
 
 #include "../common/adc_traits.h"
 
-/*  DEFINITIONS OF NETWORK CONPONENTS INTERFACES  */
+/*  DEFINITIONS OF NETWORK COMPONENTS INTERFACES  */
 
+
+/*
+    struct NetService {
+        typedef ImplementationDependentT netservice_ident_t;
+        typedef ImplementationDependentT async_ctx_t;
+        typedef ImplementationDependentT endpoint_t;
+
+        template<typename Rep, typename Period>
+        auto asyncAccept(const endpoint_t&, const async_ctx_t&, const std::chrono::duration<Rep, Period>&)
+
+        template<typename Rep, typename Period>
+        auto asyncConnect(const endpoint_t&, const async_ctx_t&, const std::chrono::duration<Rep, Period>&)
+
+        template<typename Rep, typename Period, adc::traits::adc_input_char_range R>
+        auto asyncSend(const R&, const async_ctx_t&, const std::chrono::duration<Rep, Period>&)
+
+        template<typename Rep, typename Period>
+        auto asyncReceived(const async_ctx_t&, const std::chrono::duration<Rep, Period>&)
+
+        template<typename Rep, typename Period>
+        auto accept(const endpoint_t&, const async_ctx_t&, const std::chrono::duration<Rep, Period>&)
+
+        template<typename Rep, typename Period>
+        auto connect(const endpoint_t&, const async_ctx_t&, const std::chrono::duration<Rep, Period>&)
+
+        template<typename Rep, typename Period, adc::traits::adc_input_char_range R>
+        auto send(const R&, const std::chrono::duration<Rep, Period>&)
+
+        template<adc::traits::adc_output_char_range R, typename Rep, typename Period>
+        R received(const std::chrono::duration<Rep, Period>&)
+
+    }
+*/
 template <typename SRVT>
 concept adc_netservice_c = requires(SRVT srv, const SRVT srv_const) {
     typename SRVT::netservice_ident_t;
@@ -49,3 +82,39 @@ concept adc_netservice_c = requires(SRVT srv, const SRVT srv_const) {
         }(srv, std::string(), typename SRVT::async_ctx_t(), std::chrono::seconds(1));
     };
 };
+
+
+/*  NETWORK SESSION  */
+
+template<typename SESST>
+concept adc_netsession_c = std::derived_from<SESST, std::enable_shared_from_this<SESST>>
+                           && requires(SESST sess, const SESST sess_const) {
+                                  typename SESST::netsession_ident_t;
+
+                                  // netsession_ident_t ident() const
+                                  { sess_const.ident() } -> std::same_as<typename SESST::netsession_ident_t>;
+
+                                  sess.start();
+                                  sess.stop();
+                              };
+
+
+
+/*  NETWORK SESSION-LEVEL PROTOCOL  */
+
+template<typename SESS_PROTOT>
+concept adc_netsession_proto_c = requires(SESS_PROTOT proto, const SESS_PROTOT proto_const) {
+    typename SESS_PROTOT::proto_ident_t;
+
+    // proto_ident_t ident() const (const method)
+    { proto_const.ident() } -> std::same_as<typename SESS_PROTOT::proto_ident_t>;
+
+    []<std::input_iterator IT>(const SESS_PROTOT &proto, IT begin, IT end) -> std::tuple<IT, IT, bool> {
+        return proto.parse(begin, end);
+    };
+
+    // must return a view of R-range!
+    []<std::ranges::range R>(SESS_PROTOT obj, const R &r) -> std::ranges::view auto {
+        return obj.from(r);
+    }(proto, std::string());
+};