Hi Mark,
Good question
The number 4 is really 4 DLU's (Device License Units) for CUCM 5.x, 6.x and 7.x
set ups.
DLU's are related to Phone Licenses and are weighted
based upon the IP Phone model being utilised. The higher the model the higher the number
of DLU's.
The table below shows how to identify how many DLU's are required per phone model.
Device Type - Cost in DLUs
Cisco VGC Phone (Voice Gateway Controlled, e.g. behind VG248)
Cisco VGC Virtual Phone (Voice Gateway Controlled, e.g. behind VG248)
Analog Phone
CTI Port
0 -DLU's
Cisco Unified IP Phone 7902
Cisco Unified Mobile Communicator
Cisco Unified Presence user
1 -DLU's
Cisco Unified IP Phone 7905, 7906G, 7910, _12_S, 12 SP, 12 SP Plus, 30 SP Plus ATA 186, 3911
Cisco Unified Mobility user (hardphone + mobile device) H.323 Client
2 -DLU's
Cisco Unified IP Phone 7911G, 7912, 7937
Cisco IP Communicator
Cisco Unified Personal Communicator
3 -DLU's
Cisco Unified IP Phone 7920, 7921, 7925, 7931G
Cisco Unifed Mobility user (MobileConnect only - no hardphone)
4 -DLU's
Cisco Unified IP Phone 7935, 7936
3 -DLU's
Cisco Unified IP Phone 7940, 7941, 7941G-GE, 7942G, 7945G, 7960, 7961, 7961GGE,
7962G, 7965G
4 -DLU's
Cisco Unified IP Phone 7970, 7971, 7975G 5 -DLU's
Cisco Unified IP Phone 7985
TelePresence endpoints: CTS 1000, CTS 3000
IP-STE (Secure Terminal Equipment) Endpoint
6 -DLU's
Third-party SIP Device (Basic) 3 -DLU's
Third-party SIP Device (Advanced)6 -DLU's
Third-party Dual-mode Mobile Device 6-DLU's
Other Phone 5 -DLU's
Hope this helps!
Rob
