CUCM Licensing DLUs

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Dec 23rd, 2007
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Cisco seem to sell two different types of device license units with one being for Cisco devices (e.g. LIC-CM-DL-100

) and the other being for third party SIP phones (e.g. LIC-3PTY-DL-100=


In the CUCM6.0 System > Licensing > License Unit Report window the system does not seem to differentiate between the two types but just lists Phone License Feature units.

My question is therefore is it important which type of DLUs I buy and, if I buy the one for Cisco devices, are they usable with third party SIP phones and vice-versa?


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Rob Huffman Sun, 12/23/2007 - 10:49
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Hi James,

Excellent question! I have spent many hours trying to decipher this whole licensing maze :) You are correct that all DLU's are lumped together at the end of the day, but the documentation does differenciate between the two license types. It seems like a "one way" street in that Cisco IP Phones can use the Third Party SIP licenses but not vice-versa. Have a look at the clips below;

Device licenses are required for Cisco devices and for third-party devices,*** with the flexibility to replace third-party devices with Cisco devices. Device licenses are sold in increments of device-license units (DLU's). Device-license units are assigned to each device connected to Cisco Unified CallManager 5.0. Each device is assigned a unit number based on the type and capabilities of the device. Devices with more complex and high-end capabilities are assigned a higher number of units compared to devices with basic capabilities,

From this good Q & A doc;


Application and phone software licenses are enforced. The system manages the maximum number of devices that can be provisioned.

• Each device (Cisco Unified IP phones, third-party devices, and video devices) provisioned in the system corresponds to a number of device license units (DLUs), depending on its capabilities; the total number of units is managed in Cisco Unified CallManager to determine capacity.

• DLUs must be purchased to cover the number of devices connected to Cisco Unified CallManager.

• Third-party SIP devices require DLUs for operation with Cisco Unified CallManager.

Hope this helps!



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