diff --git a/config.h b/config.h
index 78924f5..e2ba1a4 100644
--- a/config.h
+++ b/config.h
@@ -4,10 +4,10 @@
 #define ETHERNET
 #define LINK_MTU 1536
 
-#define MAX_TCPSOCKETS 4
-#define MAX_UDPSOCKETS 2
-#define RXBUF_SIZE LINK_MTU * 8
-#define TXBUF_SIZE LINK_MTU * 2
+#define MAX_TCPSOCKETS 20
+#define MAX_UDPSOCKETS 1
+#define RXBUF_SIZE LINK_MTU * 4
+#define TXBUF_SIZE LINK_MTU * 16
 
 #define MAX_NEIGHBORS 16
 
diff --git a/femtotcp.h b/femtotcp.h
index 986859a..afc2d0d 100644
--- a/femtotcp.h
+++ b/femtotcp.h
@@ -98,7 +98,6 @@ void ipstack_ipconfig_set(struct ipstack *s, ip4 ip, ip4 mask, ip4 gw);
 void ipstack_ipconfig_get(struct ipstack *s, ip4 *ip, ip4 *mask, ip4 *gw);
 
 struct ll *ipstack_getdev(struct ipstack *s);
-ip4 atoip4(const char *ip);
 
 /* Callback flags */
 #define CB_EVENT_READABLE 0x01 /* Accepted connection or data available */
@@ -110,6 +109,43 @@ void ipstack_register_callback(struct ipstack *s, int sock_fd, void (*cb)(int so
 /* External requirements */
 uint32_t ipstack_getrandom(void);
 
+/* Inline utility functions */
+static inline uint32_t atou(const char *s)
+{
+    uint32_t ret = 0;
+    while (*s >= '0' && *s <= '9') {
+        ret = ret * 10 + (*s - '0');
+        s++;
+    }
+    return ret;
+}
 
+static inline ip4 atoip4(const char *ip)
+{
+    ip4 ret = 0;
+    int i = 0;
+    int j = 0;
+    for (i = 0; i < 4; i++) {
+        ret |= (atou(ip + j) << (24 - i * 8));
+        while (ip[j] != '.' && ip[j] != '\0') j++;
+        if (ip[j] == '\0') break;
+        j++;
+    }
+    return ret;
+}
+
+static inline void iptoa(ip4 ip, char *buf)
+{
+    int i, j = 0;
+    buf[0] = 0;
+    for (i = 0; i < 4; i++) {
+        uint8_t x = (ip >> (24 - i * 8)) & 0xFF;
+        if (x > 99) buf[j++] = x / 100 + '0';
+        if (x > 9) buf[j++] = (x / 10) % 10 + '0';
+        buf[j++] = x % 10 + '0';
+        if (i < 3) buf[j++] = '.';
+    }
+    buf[j] = 0;
+}
 
 #endif
diff --git a/src/femtotcp.c b/src/femtotcp.c
index a8bf2d3..1ebf0b4 100644
--- a/src/femtotcp.c
+++ b/src/femtotcp.c
@@ -2106,26 +2106,3 @@ void ipstack_ipconfig_get(struct ipstack *s, ip4 *ip, ip4 *mask, ip4 *gw)
     *gw = s->ipconf.gw;
 }
 
-static uint32_t atou(const char *s)
-{
-    uint32_t ret = 0;
-    while (*s >= '0' && *s <= '9') {
-        ret = ret * 10 + (*s - '0');
-        s++;
-    }
-    return ret;
-}
-
-ip4 atoip4(const char *ip)
-{
-    ip4 ret = 0;
-    int i = 0;
-    int j = 0;
-    for (i = 0; i < 4; i++) {
-        ret |= (atou(ip + j) << (24 - i * 8));
-        while (ip[j] != '.' && ip[j] != '\0') j++;
-        if (ip[j] == '\0') break;
-        j++;
-    }
-    return ret;
-}
diff --git a/src/port/posix/bsd_socket.c b/src/port/posix/bsd_socket.c
index 0e70d5e..6e3cd75 100644
--- a/src/port/posix/bsd_socket.c
+++ b/src/port/posix/bsd_socket.c
@@ -17,7 +17,7 @@
 
 static __thread int in_the_stack = 1;
 static struct ipstack *IPSTACK = NULL;
-pthread_mutex_t ipstack_mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t ipstack_mutex;
 
 /* host_ functions are the original functions from the libc */
 static int (*host_socket  ) (int domain, int type, int protocol) = NULL;
@@ -558,6 +558,7 @@ void __attribute__((constructor)) init_femto_posix() {
     swap_socketcall(select, "select");
     swap_socketcall(fcntl, "fcntl");
 
+    pthread_mutex_init(&ipstack_mutex, NULL);
     ipstack_init_static(&IPSTACK);
     tapdev = ipstack_getdev(IPSTACK);
     if (tap_init(tapdev, "femt0", linux_ip.s_addr) < 0) {
diff --git a/src/port/raspberry-pico-usb-server/CMakeLists.txt b/src/port/raspberry-pico-usb-server/CMakeLists.txt
index f977e47..603cfe2 100644
--- a/src/port/raspberry-pico-usb-server/CMakeLists.txt
+++ b/src/port/raspberry-pico-usb-server/CMakeLists.txt
@@ -18,6 +18,7 @@ add_executable(${PROJECT})
 target_sources(${PROJECT} PUBLIC
   ${CMAKE_CURRENT_LIST_DIR}/src/main.c
   ${CMAKE_CURRENT_LIST_DIR}/src/rand.c
+  ${CMAKE_CURRENT_LIST_DIR}/src/motd.c
   ${CMAKE_CURRENT_LIST_DIR}/src/usb_descriptors.c
   ${CMAKE_CURRENT_LIST_DIR}/../../femtotcp.c
   )
diff --git a/src/port/raspberry-pico-usb-server/Makefile b/src/port/raspberry-pico-usb-server/Makefile
index 3aeaf01..7d3fd1b 100644
--- a/src/port/raspberry-pico-usb-server/Makefile
+++ b/src/port/raspberry-pico-usb-server/Makefile
@@ -1964,6 +1964,30 @@ src/main.c.s:
 	$(MAKE) $(MAKESILENT) -f CMakeFiles/raspberry-pico-usb-server.dir/build.make CMakeFiles/raspberry-pico-usb-server.dir/src/main.c.s
 .PHONY : src/main.c.s
 
+src/motd.obj: src/motd.c.obj
+.PHONY : src/motd.obj
+
+# target to build an object file
+src/motd.c.obj:
+	$(MAKE) $(MAKESILENT) -f CMakeFiles/raspberry-pico-usb-server.dir/build.make CMakeFiles/raspberry-pico-usb-server.dir/src/motd.c.obj
+.PHONY : src/motd.c.obj
+
+src/motd.i: src/motd.c.i
+.PHONY : src/motd.i
+
+# target to preprocess a source file
+src/motd.c.i:
+	$(MAKE) $(MAKESILENT) -f CMakeFiles/raspberry-pico-usb-server.dir/build.make CMakeFiles/raspberry-pico-usb-server.dir/src/motd.c.i
+.PHONY : src/motd.c.i
+
+src/motd.s: src/motd.c.s
+.PHONY : src/motd.s
+
+# target to generate assembly for a file
+src/motd.c.s:
+	$(MAKE) $(MAKESILENT) -f CMakeFiles/raspberry-pico-usb-server.dir/build.make CMakeFiles/raspberry-pico-usb-server.dir/src/motd.c.s
+.PHONY : src/motd.c.s
+
 src/rand.obj: src/rand.c.obj
 .PHONY : src/rand.obj
 
@@ -2246,6 +2270,9 @@ help:
 	@echo "... src/main.obj"
 	@echo "... src/main.i"
 	@echo "... src/main.s"
+	@echo "... src/motd.obj"
+	@echo "... src/motd.i"
+	@echo "... src/motd.s"
 	@echo "... src/rand.obj"
 	@echo "... src/rand.i"
 	@echo "... src/rand.s"
diff --git a/src/port/raspberry-pico-usb-server/src/main.c b/src/port/raspberry-pico-usb-server/src/main.c
index 0303a3b..23730b5 100644
--- a/src/port/raspberry-pico-usb-server/src/main.c
+++ b/src/port/raspberry-pico-usb-server/src/main.c
@@ -18,7 +18,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
  *
  * *****
- * 
+ *
  * Based on LwIP drivers for TinyUSB,
  * Copyright (c) 2020 Peter Lawrence (MIT Licensed),
  * which was also influenced by lrndis https://github.com/fetisov/lrndis
@@ -44,6 +44,7 @@
 #include "config.h"
 #include "femtotcp.h"
 
+extern char MOTD[];
 
 /* Our globals */
 static struct ipstack *IPStack = NULL;
@@ -56,7 +57,7 @@ uint8_t tusb_net_rxbuf_used[2] =  {0, 0};
 uint8_t tusb_net_txbuf[LINK_MTU][2];
 uint16_t tusb_net_txbuf_sz[2] = {0, 0};
 
-/* Fixed mac-address for the raspberry side of the link. 
+/* Fixed mac-address for the raspberry side of the link.
  * it is suggested that the first byte is 0x02 to indicate a link-local address
  */
 uint8_t tud_network_mac_address[6] = {0x02, 0x02, 0x84, 0x6A, 0x96, 0x00};
@@ -170,6 +171,64 @@ void tud_network_init_cb(void)
 {
 }
 
+/* Telnet server (telnetd) initialization */
+static int tel_s = -1;
+static int tel_c = -1;
+
+static void telnet_cb(int fd, uint16_t event, void *arg)
+{
+    struct ipstack_sockaddr_in addr;
+    uint32_t socklen = sizeof(addr);
+    (void)arg;
+    if ((fd == tel_s) && (event & CB_EVENT_READABLE) && (tel_c == -1)) {
+        char ipaddr[16];
+        char welcome_msg[32];
+        tel_c = ft_accept(IPStack, tel_s, (struct ipstack_sockaddr*)&addr, &socklen);
+        if (tel_c > 0) {
+            iptoa(ee32(addr.sin_addr.s_addr), ipaddr);
+            snprintf(welcome_msg, sizeof(welcome_msg), "Welcome %s!\n", ipaddr);
+            ft_write(IPStack, tel_c, MOTD, strlen(MOTD));
+            ft_write(IPStack, tel_c, welcome_msg, strlen(welcome_msg));
+        }
+    }
+#if 0
+    else if ((fd == tel_c) && (event & CB_EVENT_READABLE  )) {
+        int ret;
+        ret = ft_recv((struct ipstack *)arg, tel_c, buf, sizeof(buf), 0);
+        if (ret != -11) {
+            if (ret < 0) {
+                printf("Recv error: %d\n", ret);
+                ft_close((struct ipstack *)arg, tel_c);
+            } else if (ret == 0) {
+                printf("Client side closed the connection.\n");
+                ft_close((struct ipstack *)arg, tel_c);
+                printf("Server: Exiting.\n");
+                exit_ok = 1;
+            } else if (ret > 0) {
+                printf("recv: %d, echoing back\n", ret);
+                tot_recv += ret;
+            }
+        }
+    }
+#endif
+}
+
+
+static void telnetd_init(void)
+{
+    struct ipstack_sockaddr_in addr;
+    if (tel_s < 0)
+        tel_s = ft_socket(IPStack, AF_INET, IPSTACK_SOCK_STREAM, 0);
+    ipstack_register_callback(IPStack, tel_s, telnet_cb, NULL);
+
+    addr.sin_family = AF_INET;
+    addr.sin_port = ee16(23);
+    addr.sin_addr.s_addr = 0;
+
+    ft_bind(IPStack, tel_s, (struct ipstack_sockaddr *)&addr, sizeof(addr));
+    ft_listen(IPStack, tel_s, 1);
+}
+
 int main(void)
 {
     struct ll *tusb_netdev;
@@ -197,6 +256,8 @@ int main(void)
     ipstack_ipconfig_set(IPStack, atoip4("192.168.7.2"),
             atoip4("255.255.255.0"), atoip4("192.168.7.1"));
 
+    telnetd_init();
+
     board_led_off();
     while (1) {
         tud_task();
diff --git a/src/port/raspberry-pico-usb-server/src/motd.c b/src/port/raspberry-pico-usb-server/src/motd.c
new file mode 100644
index 0000000..a8ff5c6
--- /dev/null
+++ b/src/port/raspberry-pico-usb-server/src/motd.c
@@ -0,0 +1,13 @@
+const char MOTD[] = 
+"         \n"
+"   /\\_/\\ \n"
+"  ( o.o )\n"
+"   > ^ <                          ⭐️                  ⭐️       ⭐️              \n"
+"                                                                            \n"
+"  🟪🟪🟪🟪  ⭐️                 ⭐️  🟪            🟪🟪🟪🟪🟪   🟪🟪🟪 🟪🟪🟪    \n"
+"⭐️🟪       🟪🟪   🟪🟪🟪🟪🟪🟪   🟪🟪🟪🟪   🟪🟪     🟪     🟪       🟪    🟪  \n"
+"  🟪🟪🟪 🟪🟪🟪🟪 🟪    🟪    🟪   🟪     🟪    🟪   🟪 ⭐️  🟪       🟪🟪🟪    \n"
+"  🟪     🟪       🟪    🟪    🟪   🟪     🟪    🟪   🟪     🟪       🟪  ⭐️    \n"
+"  🟪       🟪🟪🟪 🟪    🟪    🟪     🟪🟪   🟪🟪     🟪       🟪🟪🟪 🟪        \n"
+"                                  ⭐️                             by Danielinux \n"
+"Best viewed in (80 x 30)\n";