Update WifiInterface.md

Make changes from #472 after reviewing on test site.

Author: Amanda Butler

docs/reference/api/connectivity/networksocket/WifiInterface.md

@@ -4,23 +4,32 @@
 
 The WifiInterface provides a simple C++ API for connecting to the internet over a Wi-Fi device.
 
-There are multiple [Wi-Fi components](https://os.mbed.com/components/cat/wifi/) that implement the WiFiInterface class. The example below uses the [ESP8266Interface](https://github.com/armmbed/esp8266-driver).
-
 ### Wi-Fi class reference
 
 [![View code](https://www.mbed.com/embed/?type=library)](https://os.mbed.com/docs/v5.8/mbed-os-api-doxy/class_wi_fi_interface.html)
 
 ### Usage
 
-To bring up the network interface:
+To bring up the network interface of an external Wi-Fi device (for example, the ESP8266Interface):
 
-1. Instantiate an implementation of the WiFiInterface class (for example, the ESP8266Interface).
+1. Instantiate an implementation of the WiFiInterface class.
+    1. Initialize the AT command parser.
 1. Call the `connect` function with an SSID and password for the Wi-Fi network.
-1. Once connected, the WiFiInterface can be used as a target for opening [network sockets](/docs/v5.8/reference/network-socket.html).
+    1. Command the Wi-Fi device to connect to network.
+1. Once connected, you can use the WiFiInterface as a target for opening [network sockets](/docs/v5.8/reference/network-socket.html).
+
+### Troubleshooting information
+
+Network interface `connect` failure reasons:
+
+1. Check that the SSID and password are correct.
+1. Check that the IP address configuration service is working.
 
 ### Wi-Fi example
 
-Here is an example of an HTTP client program. The program brings up an ESP8266 as the underlying network interface, and uses it to perform an HTTP transaction over a TCPSocket:
+Here is an example of an HTTP client program. The program brings up an ESP8266 as the underlying network interface, and uses it to perform an HTTP transaction over a TCPSocket. There are multiple [Wi-Fi components](https://os.mbed.com/components/cat/wifi/) that implement the WiFiInterface class. The example below uses the [ESP8266Interface](https://github.com/armmbed/esp8266-driver) and [OdinWiFiInterface](https://github.com/u-blox/ublox-odin-w2-drivers-docs-mbed-5). 
+
+The ESP8266Interface uses AT commands over serial interface to connect to an external Wi-Fi device. The OdinWiFiInterface provides an Ethernet-like driver to the Mbed OS network stack. The network stack uses the driver to connect to Wi-Fi:
 
 [![View code](https://www.mbed.com/embed/?url=https://os.mbed.com/teams/mbed_example/code/TCPSocketWiFi_Example/)](https://os.mbed.com/teams/mbed_example/code/TCPSocketWiFi_Example/file/6a4e57edc2b2/main.cpp)