Update IPv6 demo ReadMe (#1004)

* Update ReadMe

* Update setup requirement

* Update UDP demo info

* Update comment

2 files changed, 87 insertions, 51 deletions

diff --git a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/FreeRTOSConfig.h b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/FreeRTOSConfig.h
index af07060b7..18ae8ae50 100644
--- a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/FreeRTOSConfig.h
+++ b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/FreeRTOSConfig.h
@@ -42,17 +42,12 @@
 * the demo) are contained in FreeRTOSIPConfig.h.
 *----------------------------------------------------------*/
 
-#define NETCAT_PORT_NR                             5555
-#define AMAZON_GO_SERVER                           9000
-#define XILINX_ZYNQ                                7
-
 /* Used for IPv6 validation */
-#define configECHO_SERVER_ADDR_STRING             "fe80::a53b:3371:d92f:970b"
-
+#define configECHO_SERVER_ADDR_STRING              "fe80::a53b:3371:d92f:970b"
 /* Used for IPv4 validation */
-/* #define configECHO_SERVER_ADDR_STRING              "192.168.1.3" */
+/* #define configECHO_SERVER_ADDR_STRING           "192.168.1.3" */
 
-#define configECHO_SERVER_PORT                     AMAZON_GO_SERVER
+#define configECHO_SERVER_PORT                     7
 
 
 #define configENABLE_BACKWARD_COMPATIBILITY        1
diff --git a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/ReadMe.md b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/ReadMe.md
index 61020507b..5b968de23 100644
--- a/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/ReadMe.md
+++ b/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_IPv6_Demo/IPv6_Multi_WinSim_demo/ReadMe.md
@@ -1,11 +1,14 @@
-# FreeRTOS+TCP IPv6 Demo
+# FreeRTOS+TCP IPv6 Multi-Endpoint Demo
 
-The FreeRTOS+TCP IPv6/multiple-interface source code and example projects are
-currently provided in the FreeRTOS+TCP repository's "feature/ipv6_multi_beta"
-branch. These demos only require the FreeRTOS+TCP IPv6/multiple Interface
-source code and the FreeRTOS-Kernel.
+The IPv6_Multi_WinSim Visual studio demo showcases the Multiple Interfaces (or
+rather the multiple endpoints) functionality of the FreeRTOS+TCP library.
+The Windows Simulator environment doesn't actually have multiple
+interfaces which can be used by FreeRTOS and thus, this demo shows
+the use of different endpoints which will be resolved by the OS having multiple
+interfaces. It shows that the library will use different endpoints (IP-addresses)
+to connect to IP-addresses on different subnets (or using different netmasks).
 
-## Setting up the workspace:
+## Setting up the workspace
 
 Clone the submodules used in the FreeRTOS repo:
 
@@ -31,7 +34,7 @@ git submodule update --checkout
 ```
 
 The FreeRTOS+TCP Multiple Interface Visual Studio project file is in the following
-directory: `FreeRTOS-Plus\Demo\FreeRTOS_Plus_TCP_IPv6_Demo\IPv6_Multi_WinSim_dem`
+directory: `FreeRTOS-Plus\Demo\FreeRTOS_Plus_TCP_IPv6_Demo\IPv6_Multi_WinSim_demo`
 
 In FreeRTOS_Plus_TCP_IPv6_Multi.props, you will find a couple of macros that indicate
 the location of source files:
@@ -43,24 +46,72 @@ the location of source files:
 - PLUS_TCP_INCLUDE_DIR>  The FreeRTOS+TCP header files
 - UTILITIES_SOURCE_DIR   The location of the tcp_utilities directory
 
-You can changes these directory to let the proyejct work with a different
+You can changes these directory to let the project work with a different
 source tree.
 
-The Multiple Interface Visual studio demo showcases the Multiple Interfaces (or
-rather the multiple endpoints) functionality of the FreeRTOS+TCP
-IPv6/multi-interface library. The Windows Simulator environment doesn't actually
-have multiple interfaces which can be used by FreeRTOS and thus, this demo shows
-the use of different endpoints which will be resolved by the OS having multiple
-interfaces. It shows that the library will use different endpoints (IP-addresses)
-to connect to IP-addresses on different subnets (or using different netmasks).
-The instructions for the full Windows demo are still relevant though as they
-describe how to set up the WinPCap development environment, how to set the IP
-address, and other such items. Note that, as delivered, configUSE_DHCP is set to 0,
-so a static IP address is used. The instructions are provided on the following URL,
-see the "Hardware Setup" section:
-http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/examples_FreeRTOS_simulator.html
+## Prerequisites
+
+[Optional] Running IPv4 demo [FreeRTOS_Plus_TCP_Minimal_Windows_Simulator](https://github.com/FreeRTOS/FreeRTOS/tree/main/FreeRTOS-Plus/Demo/FreeRTOS_Plus_TCP_Minimal_Windows_Simulator)
+The instructions are provided on the following URL, see the ["Hardware Setup" and "Software Setup"](http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/examples_FreeRTOS_simulator.html).
+This will give more hands on experience of running Echo server and client.
+
+For this demo, FreeRTOS configuration file *FreeRTOSConfig.h* needs to be updated as shown below :
+
+*Client Configuration* :
+1. `configIP_ADDR0/3`         : Setup with client IP address, when DHCP is disabled.
+2. `configNET_MASK0/3`        : Setup with the appropriate network mask.
+3. `configGATEWAY_ADDR0/3 `   : Setup with Default Gateway address of Client IP.
+4. `configDNS_SERVER_ADDR0/3` : Setup wit DNS Server address of Client IP.
+
+*Server Configuration :*
+1. `configECHO_SERVER_ADDR_STRING` as an IPv6 Server IP address for IPv6
+    validation, it can be updated to IPv4 address for IPv4 validations.
+2. `configECHO_SERVER_PORT` Needs to be setup for the Server port number.
+
+Note that, as delivered, configUSE_DHCPv6 is set to 0, so a static IP address is used.
+
+## Selecting the Examples to Run
+
+### The TCP client example:
+
+This example can be enabled by setting the `mainCREATE_TCP_ECHO_TASKS_SINGLE`
+macro to 1 at the top of the project's main.c source file.
+
+The example creates two RTOS tasks that send TCP echo requests to an external
+echo server using the echo port set in FreeRTOSConfig.h, then wait to receive
+the echo reply within the same RTOS task.
+
+The IP address of the echo server must be configured by updating the `configECHO_SERVER_ADDR_STRING`
+as IPv4 or IPv6 address and server port number must be updated as `configECHO_SERVER_PORT` in FreeRTOSConfig.h.
+The echo server must be enabled and not blocked by a firewall.
+
+### The TCP server example:
+
+This example can be enabled by setting the `mainCREATE_TCP_ECHO_SERVER_TASK`
+macro to 1 at the top of the project's main.c source file.
+
+This example creates an echo server that listens for echo requests on
+the standard echo protocol port number 7. It then echos back any data
+received on that connection.
+
+### The UDP Echo Client example
+
+The demo also demonstrates a IPv4/IPv6 UDP echo client which can be enabled by
+setting the `mainCREATE_UDP_ECHO_TASKS_SINGLE` macro to 1 in the main file.
 
-The IPv6_Multi_WinSim_demo demo performs some basic network activities:
+The UDP Echo Client creates a task and sends messages to the IP address and port
+defined as `configECHO_SERVER_ADDR_STRING` (either v4 or v6 address) 
+and configECHO_SERVER_PORT respectively in the FreeRTOSConfig.h file and expect to
+get echo of the messages back. There should be a UDP echo server running in the 
+given IP and port.
+
+These RTOS tasks are self checking and will trigger a configASSERT() failure if they
+detect a difference in the data that is received from that which was sent. As these
+RTOS tasks use UDP, which can legitimately loose packets, they can cause configASSERT()
+failures when they are executed in a less than perfect networking environment.
+
+#### *Note* Sample TCP and UDP echo server can be found at the last section of ReadME.
+### The IPv6_Multi_WinSim_demo demo also performs some basic network activities:
 
 - ARP address resolution for IPv4 addresses on the LAN
 - Neighbour Discovery for IPv6 addresses on the LAN
@@ -71,10 +122,11 @@ The IPv6_Multi_WinSim_demo demo performs some basic network activities:
 - Ping any server on the web or on the LAN, , with IPv4 or IPv6
 
 The demo can be easily adapted to your own needs. It works like a command line
-interface ( CLI ) that performs the above tasks.
+interface ( CLI ) that performs the above tasks. Although it is called a CLI,
+the demo does not have a STDIN. The commands are hard-coded in main.c pcCommandList.
 
-Here are some examples of valid command lines, using the keywords “http”, “ping”,
-“dnsq”, and “ntp:
+The pcCommandList options can be uncommented to run the commands. Here are some examples of
+valid command lines, using the keywords “http”, “ping”, “dnsq”, and “ntp:
 
     "http4 google.co.uk /index.html",
     "http6 amazon.com /index.html",
@@ -87,27 +139,13 @@ Here are some examples of valid command lines, using the keywords “http”, �
 The last line will first lookup the mentioned NTP server, send a request, and wait
 for a reply. The time will be printed in the logging.
 
-Although it is called a CLI, the demo does not have a STDIN. The commands are
-hard-coded in main.c
-
 The keywords can have some single-letter suffices: 4 or 6 ( for IPv4/6 ), “a” to do
 an asynchronous DNS lookup, and “c” to clear all caches before starting the task.
 
+## Sample Echo server
+##### Prerequisites : [Install go](https://go.dev/doc/install)
 
-## Using the UDP Echo Client
-
-The demo also demonstrates a IPv4/IPv6 UDP echo client which can be enabled by
-setting the `mainCREATE_UDP_ECHO_TASKS_SINGLE` macro to 1 in the main file.
-
-The UDP Echo Client creates a task and sends messages to the IP address and port
-defined as `configECHO_SERVER_ADDR_STRING` (either v4 or v6 address) 
-and configECHO_SERVER_PORT respectively in the FreeRTOSConfig.h file and expect to
-get echo of the messages back. There should be a UDP echo server running in the 
-given IP and port.
-
-
-#### Sample UDP echo server in Go: 
-
+#### Sample UDP server in Go:
 ``` go
 
 // Filename: echo_server.go 
@@ -165,4 +203,7 @@ func main() {
 
 The UDP Echo Client demo also demonstrates the UDP zero copy for both IPv4 and IPv6
 (based on the IP type), it can be enabled by setting `USE_ZERO_COPY` macro of the
-UDPEchoClient_SingleTasks.c file to 1.
\ No newline at end of file
+UDPEchoClient_SingleTasks.c file to 1.
+
+#### Sample TCP server in Go:
+[TCP Echo Server](https://github.com/aws/amazon-freertos/tree/main/tools/echo_server)