So the question becomes simpler when think of Roles as being relative entity a performs a role in relation to entity b. Your Customer consider's themselves to be a User and their Customer's are Customers to them. The only person who cares about your Customer as a Customer is you. You have two roles in the system as an Administrator and as a User.

I saw the explanation that you have Employees who interact with the End Customers through your chat software (let's call this role Agent). For clarification, does the Agent represent himself as an employee of your User?

I would argue that the role is still Agent, User, Customer. Referring to your User as a customer just confuses things. (As you can see).

I've had it worse...I had to work on three levels of indirection. There was a Company entity which in some cases were direct Users of our application. They had Accounts that they sold various packages from our offerings to and they tracked Customers for those Accounts. 

What do you call a customer's customer in a specification document, use case, or scenario?
I'm using a WIFI USB adapter : TP-Link TL-WN725N Nano Adaptateur USB wireless N 150 Mbps. I plug it to my raspberry and configured it in /etc/network/interfaces . I added this :

allow-hotplug wlan0 
iface wlan0 inet dhcp 
wpa-ssid "MY NETWORK SSID"


I dont need password to connect.

then sudo reboot

when I launch ifconfig I got this (no wlan detected).

eth0      Link encap:Ethernet  HWaddr b8:27:eb:d5:44:b8  
          inet addr:192.168.0.2  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:53 errors:0 dropped:0 overruns:0 frame:0
          TX packets:90 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:7022 (6.8 KiB)  TX bytes:9278 (9.0 KiB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:14 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1330 (1.2 KiB)  TX bytes:1330 (1.2 KiB)

