All the configuration are made with this in mind:
0039 as Italy dialing code 
02 as Milan area code
XXXX 4 digits subscriber + XXX 3 digits DID 


Location: Datacenter Lab PC
Device:   Cisco 2821 E1 tandem
0039 + 02 + ---- +
                 |
Serial0/0/0:15   + 2000XXX => Routing to Leo's home via icE1usb/line 1 
Serial0/0/1:15   + 1000XXX => Routing to commander 2 lab
Serial0/1/0:15   + 4000 + 4000XXX => MAX 2000
Serial0/1/1:15   + Routing to 0049 + 30 via icE1usb/line 0
                 | Module 2 allocated to further E1 Mutiflex
      BRI0/3/0   + 3001 => Test only NT/TE
      BRI0/3/1   + 3002 => Test only NT/TE allocated for PSTN usage via Patton/SIP Asterisk SBC and C*NET                 
Internal Cisco   + 5000 => FAX to mail

Device:   Cisco 2901 E1 tandem
Serial0/0/0:15   + Disconnected
Serial0/0/1:15   + Disconnected
      BRI0/3/0   + Disconnected
      BRI0/3/1   + Disconnected

Device:   Commander Basic 2
0039 + 02 + 1000 +
                 |
   S0 Slot A/5   + 122 => LANCOM 1700 | LANCAPI Win NT4
   S0 Slot A/6   + 123 => LAB Phone
   S0 Slot A/7   + 124 => Cisco 1800
   S0 Slot A/8   + 125 => Gigaset Base
                 |
  a/b Slot E/1   + 131 => Multitech V.92 Modem
           E/2   + 132 => LAB Phone   

Location: Leo's Home
Device:   Commander Basic 2 
0039 + 02 + 2000 +
                 |
   S0 Slot A/5   + 222 => Phone 
           A/6   + 223 => Elsa 1100 Office
           A/7   + 224 => Zyxel 202H
           A/8   + 225 => Gigaset Base
                 |
  a/b Slot E/1   + 231 => GeoPort
           E/2   + 232 => 56k USR Modem
           E/3   + 233 => Thinkpad
           E/4   + 234 => Rotary Analog
           E/5   + 235 => Rotary Analog
           E/6   + 236 => USB 56k Modem Raspberry 
           E/7   + 237 => 
           E/8   + 238 =>