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CM 5 & 6 difference



does CM 6.1 have all features of CM 5.1 with same scalability?

i heard that CM6.1 is not for enterprise while CM5.1 is. is that correct? i want to buy Call Manager and don't know which version i have to buy.


S. Zamani.

5 Replies 5

Rob Huffman
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Hall of Fame Community Legend

Hi Saeed,

Good question! In fact CUCM 6.x is more Feature rich than the 5.x versions. CUCM 6.x was built based on CCM 4.2 and CUCM 5.x was built based on CCM 4.1 and thus the features carry across as such. Most people who are building new CUCM deployments these days are skipping directly to CUCM 7.x which has proven to be an excellent build. My vote would be to definitely skip 5.x

here is the related CCM 5.x and CCM 6.x info :)

Cisco CallManager 5.x Features

Call Forwarding Enhancements

Call Park

Call Pickup Group

CTI and CTI Super Provider

Dynamic Host Control Protocol (DHCP)

International Dial Plans

LDAP Directory Enhancements


Personal Directory Enhancements

Phone NTP References for SIP Phones


Roles and User Groups


Service Enhancements

SIP Line Side (Endpoints) Support

SIP Route Pattern

SIP Third-Party Phones

SIP Trunk Enhancements

TFTP Enhancements

URL Dialing

Video Telephony Enhancements

Voice Quality Metrics

Cisco Unified Communications Manager 6.0 feature enhancements:

•AAC/iLBC Voice Codec Support

•Advanced Ad Hoc Conference

•Audible Message Waiting Indicator

•Barge Enhancements

•Call Diagnostics and Voice Quality Metrics

•Call Forward Enhancements

•Call Forward All Calling Search Space Backward Compatibility

•Call Forward Overriding

•Call Pickup Notification

•Cisco Messaging Interface Enhancements

•Cisco Unified Communications Manager T1 CAS Hookflash Transfer Support

•Connected Number Display

•Credential Policy and User Authentication

•CTI Enhancements

•Device Mobility

•Directed Call Park

•Do Not Disturb

•Hold Reversion


•Licensing Enhancements

•Log Out of Hunt Groups

•Overlap Sending and Receiving for H.323 Gateways

•MGCP T.38 Enhancements

•Privacy on Hold

•Programmable Line Keys

•SCCP Optimization

•SDL Traces

•SIP Endpoints Support

•SIP Third-Party Phones Enhancements

•SIP Trunk Enhancements

Release Notes for Cisco Unified Communication Manager Release 6.1(3a)

Here is the latest and greatest:)

Release Notes for Cisco Unified Communications Manager Release 7.0(1)

Hope this helps!


Also, another great enhancement that was added in version 6 is database resiliency, meaning that if your Pub goes down user features such as call forward All, MWI, extension mobility, etc will continue to operate.



CUCM 6 is considered much more stable. CUCM 5 was the first release with the linux appliance, and as such there are a host of issues with the database and other various things. Now this will vary depending on your exact version, but from a general standpoint that is how it can be viewed.


You also have to consider 5 is based upon 4.1 so if you upgrade from 4.2, 4.3 to 5.x you lose some features- Common profiles is one of them - if yo use then at 4.2,3

There is no upgrade path from 4.2 or 4.3 to 5, you need to go to 6.


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