diff --git a/external/mesytec-mvlc b/external/mesytec-mvlc
index 22b099f..10bdc1b 160000
--- a/external/mesytec-mvlc
+++ b/external/mesytec-mvlc
@@ -1 +1 @@
-Subproject commit 22b099f2f4785122086620d25c43060e78ef7e7a
+Subproject commit 10bdc1b16dc3c9f6bbb678009fa548dab4a104d5
diff --git a/include/mesytec-node/mesytec_node_nng.h b/include/mesytec-node/mesytec_node_nng.h
index 106676d..02e40f5 100644
--- a/include/mesytec-node/mesytec_node_nng.h
+++ b/include/mesytec-node/mesytec_node_nng.h
@@ -2,6 +2,14 @@
 #define B18E3651_CA9A_43BC_AA25_810EA16533CD
 
 #include <nng/nng.h>
+#include <nng/protocol/pair0/pair.h>
+#include <nng/protocol/pipeline0/pull.h>
+#include <nng/protocol/pipeline0/push.h>
+#include <nng/protocol/pubsub0/pub.h>
+#include <nng/protocol/pubsub0/sub.h>
+#include <nng/protocol/reqrep0/req.h>
+#include <nng/protocol/reqrep0/rep.h>
+
 #include <spdlog/spdlog.h>
 
 #include <optional>
@@ -70,7 +78,7 @@ inline size_t allocated_free_space(nng_msg *msg)
     return capacity - used;
 }
 
-static nng_duration DefaultTimeout = 16;
+static nng_duration DefaultTimeout = 250;
 
 inline int set_socket_timeouts(nng_socket socket, nng_duration timeout = DefaultTimeout)
 {
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 6cb72ee..35eda19 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -34,6 +34,10 @@ function(add_node_dev_executable name)
     target_compile_options(${name} PRIVATE ${MVLC_NNG_NODE_WARN_FLAGS})
 endfunction()
 
+function(add_node_proto_dev_executable name)
+    add_node_dev_executable(${name})
+    target_link_libraries(${name} PRIVATE mnode-proto mesytec-mvlc)
+endfunction()
 
 add_node_dev_executable(pair_producer)
 add_node_dev_executable(pair_consumer)
@@ -43,9 +47,10 @@ add_node_dev_executable(mesy_nng_pipeline_main)
 add_node_dev_executable(mesy_nng_push_pull_main)
 add_node_dev_executable(mesy_nng_pub_producer)
 add_node_dev_executable(mesy_nng_sub_consumer)
-add_node_dev_executable(mnode_proto_test1)
-target_sources(mnode_proto_test1 PRIVATE thread_name.cc)
-target_link_libraries(mnode_proto_test1 PRIVATE mnode-proto mesytec-mvlc)
+
+add_node_proto_dev_executable(mnode_proto_test1)
+add_node_proto_dev_executable(mnode_proto_ping_client)
+add_node_proto_dev_executable(mnode_proto_ping_server)
 
 #add_subdirectory(qt)
 
diff --git a/src/mesytec_node_nng.cc b/src/mesytec_node_nng.cc
index a20179a..8bedd41 100644
--- a/src/mesytec_node_nng.cc
+++ b/src/mesytec_node_nng.cc
@@ -1,13 +1,5 @@
 #include "mesytec-node/mesytec_node_nng.h"
 
-#include <nng/protocol/pair0/pair.h>
-#include <nng/protocol/pipeline0/pull.h>
-#include <nng/protocol/pipeline0/push.h>
-#include <nng/protocol/pubsub0/pub.h>
-#include <nng/protocol/pubsub0/sub.h>
-#include <nng/protocol/reqrep0/req.h>
-#include <nng/protocol/reqrep0/rep.h>
-
 namespace mesytec::nng
 {
 
diff --git a/src/mnode_proto_ping_client.cc b/src/mnode_proto_ping_client.cc
new file mode 100644
index 0000000..16c52f3
--- /dev/null
+++ b/src/mnode_proto_ping_client.cc
@@ -0,0 +1,151 @@
+#include <memory>
+
+#include <mesytec-mvlc/mesytec-mvlc.h>
+#include <mesytec-mvlc/util/signal_handling.h>
+#include "proto/service.pb.h"
+#include <mesytec-node/mesytec_node_nng.h>
+
+using namespace mesytec;
+using namespace std::literals;
+
+void client_cb(void *arg);
+
+class Work
+{
+  public:
+    explicit Work(nng_socket socket)
+        : socket(socket)
+    {
+    }
+
+    ~Work()
+    {
+        nng_ctx_close(ctx);
+        nng_aio_free(aio);
+    }
+
+    void work()
+    {
+        switch (state)
+        {
+        case INIT:
+            nng_aio_alloc(&aio, client_cb, this);
+            nng_ctx_open(&ctx, socket);
+
+            state = SEND;
+            nng_aio_set_msg(aio, make_request().release());
+            nng_ctx_send(ctx, aio);
+            break;
+
+        case SEND:
+            if (auto rv = nng_aio_result(aio))
+            {
+                nng::mesy_nng_error("nng_ctx_send", rv);
+                nng::make_unique_msg(nng_aio_get_msg(aio)).reset();
+                state = SEND;
+                nng_aio_set_msg(aio, make_request().release());
+                nng_ctx_send(ctx, aio);
+            }
+            else
+            {
+                state = RECEIVE;
+                nng_ctx_recv(ctx, aio);
+            }
+            break;
+
+        case RECEIVE:
+            if (auto rv = nng_aio_result(aio))
+            {
+                nng::mesy_nng_error("nng_ctx_recv", rv);
+                state = SEND;
+                nng_aio_set_msg(aio, make_request().release());
+                nng_ctx_send(ctx, aio);
+            }
+            else
+            {
+                auto reply = nng::make_unique_msg(nng_aio_get_msg(aio));
+                handle_reply(std::move(reply));
+                state = SEND;
+                nng_aio_set_msg(aio, make_request().release());
+                nng_ctx_send(ctx, aio);
+            }
+
+            break;
+        }
+
+    }
+
+    nng::unique_msg make_request()
+    {
+        mnode::Ping ping;
+        ping.set_peer_id(42);
+        ping.set_sequence_number(++sequence_number);
+        return nng::make_message(ping.SerializeAsString());
+    }
+
+    void handle_reply(nng::unique_msg &&msg)
+    {
+        mnode::Pong pong;
+        pong.ParseFromArray(nng_msg_body(msg.get()), nng_msg_len(msg.get()));
+        if (pong.peer_id() != 42 || pong.sequence_number() != sequence_number)
+        {
+            spdlog::error("received pong with unexpected values: {}", pong.ShortDebugString());
+        }
+    }
+
+    void report()
+    {
+        spdlog::info("Work: state={}, sequence_number={}", static_cast<int>(state), sequence_number);
+    }
+
+  private:
+    enum State
+    {
+        INIT,    // allocate aio, open ctx, send first request
+        SEND,    // send request
+        RECEIVE, // receive response
+    };
+
+    mnode::Ping ping;
+    mnode::Pong pong;
+    size_t sequence_number = 0;
+    State state = INIT;
+    nng_socket socket;
+    nng_aio *aio = nullptr;
+    nng_ctx ctx;
+};
+
+void client_cb(void *arg)
+{
+    auto work = static_cast<Work *>(arg);
+    work->work();
+}
+
+int main()
+{
+    spdlog::set_level(spdlog::level::info);
+
+    auto socket = nng::make_req_socket();
+
+    if (int res = nng_dial(socket, "tcp://localhost:5555", nullptr, 0))
+    {
+        nng::mesy_nng_error("nng_dial", res);
+        return res;
+    }
+
+    mvlc::util::Stopwatch sw;
+    Work work(socket);
+    work.work();
+
+    for (;;)
+    {
+        nng_msleep(100);
+        if (sw.get_interval() >= 1s)
+        {
+            work.report();
+            sw.interval();
+        }
+    }
+
+    return 0;
+}
diff --git a/src/mnode_proto_ping_server.cc b/src/mnode_proto_ping_server.cc
new file mode 100644
index 0000000..fd75ff6
--- /dev/null
+++ b/src/mnode_proto_ping_server.cc
@@ -0,0 +1,139 @@
+#include <memory>
+
+#include <mesytec-mvlc/mesytec-mvlc.h>
+#include <mesytec-mvlc/util/signal_handling.h>
+#include "proto/service.pb.h"
+#include <mesytec-node/mesytec_node_nng.h>
+
+using namespace mesytec;
+using namespace std::literals;
+
+void server_cb(void *arg);
+
+class Work
+{
+  public:
+    explicit Work(nng_socket socket)
+        : socket(socket)
+    {
+        recvErrors_.fill(0);
+        sendErrors_.fill(0);
+    }
+
+    ~Work()
+    {
+        nng_ctx_close(ctx);
+        nng_aio_free(aio);
+    }
+
+    void work()
+    {
+        switch (state)
+        {
+        case INIT:
+            nng_aio_alloc(&aio, server_cb, this);
+            nng_ctx_open(&ctx, socket);
+            state = RECEIVE;
+            nng_ctx_recv(ctx, aio);
+            break;
+
+        case RECEIVE:
+            if (auto rv = nng_aio_result(aio))
+            {
+                if (rv != NNG_ETIMEDOUT)
+                    nng::mesy_nng_error("nng_ctx_recv", rv);
+                if (rv < static_cast<int>(recvErrors_.size()))
+                    ++recvErrors_[rv];
+                state = RECEIVE;
+                nng_ctx_recv(ctx, aio);
+                break;
+            }
+            else
+            {
+                auto reply = handle_request(nng::make_unique_msg(nng_aio_get_msg(aio)));
+                nng_aio_set_msg(aio, reply.release());
+                state = SEND;
+                nng_ctx_send(ctx, aio);
+            }
+            break;
+
+        case SEND:
+            if (auto rv = nng_aio_result(aio))
+            {
+                nng::mesy_nng_error("nng_ctx_send", rv);
+                if (rv < static_cast<int>(sendErrors_.size()))
+                    ++sendErrors_[rv];
+                nng::make_unique_msg(nng_aio_get_msg(aio)).reset();
+            }
+            state = RECEIVE;
+            nng_ctx_recv(ctx, aio);
+            break;
+        }
+    }
+
+    nng::unique_msg handle_request(nng::unique_msg &&msg)
+    {
+        ping_.ParseFromArray(nng_msg_body(msg.get()), nng_msg_len(msg.get()));
+        pong_.set_peer_id(ping_.peer_id());
+        pong_.set_sequence_number(ping_.sequence_number());
+        sequence_number = ping_.sequence_number();
+        return nng::make_message(ping_.SerializeAsString());
+    }
+
+    void report()
+    {
+        spdlog::info("Work: state={}, sequence_number={}", static_cast<int>(state), sequence_number);
+    }
+
+  private:
+    enum State
+    {
+        INIT,    // allocate aio, open ctx, receive first request
+        RECEIVE, // receive request
+        SEND,    // send response
+    };
+
+    mnode::Ping ping_;
+    mnode::Pong pong_;
+    std::uint32_t sequence_number = 0;
+    State state = INIT;
+    nng_socket socket;
+    nng_aio *aio = nullptr;
+    nng_ctx ctx;
+    std::array<size_t, 64> recvErrors_;
+    std::array<size_t, 64> sendErrors_;
+
+};
+
+void server_cb(void *arg)
+{
+    auto work = static_cast<Work *>(arg);
+    work->work();
+}
+
+int main()
+{
+    spdlog::set_level(spdlog::level::debug);
+
+    auto socket = nng::make_rep_socket();
+
+    if (int res = nng_listen(socket, "tcp://localhost:5555", nullptr, 0))
+    {
+        nng::mesy_nng_error("nng_listen", res);
+        return res;
+    }
+
+    mvlc::util::Stopwatch sw;
+    Work work(socket);
+    work.work();
+
+    for (;;)
+    {
+        nng_msleep(100);
+        if (sw.get_interval() >= 1s)
+        {
+            work.report();
+            sw.interval();
+        }
+    }
+}
diff --git a/src/mnode_proto_test1.cc b/src/mnode_proto_test1.cc
index cab5b50..c829352 100644
--- a/src/mnode_proto_test1.cc
+++ b/src/mnode_proto_test1.cc
@@ -83,14 +83,6 @@ void responder(nng_socket socket, unsigned id)
     }
 }
 
-void client_aio(nng_socket socket, unsigned id)
-{
-}
-
-void server_aio(nng_socket socket, unsigned id)
-{
-}
-
 int main()
 {
     spdlog::set_level(spdlog::level::info);
@@ -98,8 +90,6 @@ int main()
     unsigned peerId = 0;
     std::vector<std::thread> threads;
 
-    #if 1
-    {
     auto reqSocket = nng::make_req_socket();
     auto repSocket = nng::make_rep_socket();
 
@@ -108,21 +98,6 @@ int main()
 
     threads.emplace_back(std::thread(requester, reqSocket, peerId++));
     threads.emplace_back(std::thread(responder, repSocket, peerId++));
-    }
-    #endif
-
-    #if 1
-    {
-    auto reqSocket = nng::make_req_socket();
-    auto repSocket = nng::make_rep_socket();
-
-    if (int rc = nng::marry_listen_dial(reqSocket, repSocket, fmt::format("inproc://test{}", peerId).c_str()))
-        return rc;
-
-    threads.emplace_back(std::thread(client_aio, reqSocket, peerId++));
-    threads.emplace_back(std::thread(server_aio, repSocket, peerId++));
-    }
-    #endif
 
     for (auto &t: threads)
         if (t.joinable()) t.join();