CUCM Cluster implementation

[jones.jack]

Hello experts

i have a big customer who have (one pub and one sub) one unity conn and one CUP , all version are v8.6  . All systems are working so well.

The customer asked us for a cluster for 10,000 phones , so our presales team helped him for a solution which will be like as the below:-

1-CUCM Pub.

1-CUCM TFTP.

3- 5* CUCM sub.

all these servers are the same version of the old.

My questions are:-

1-What is the perfect plan to backup configuration from the running system  to the new system ?.

2-What is the most perfect solution to configure  new cluster?.This is my first time to configure some thing like that , some friends told me that only backup from the old solution and restore to the new system , after that all will be ok , but i do not understand how can i divide my configuration through t7 servers.

Thanks

[Aman Soi]

Hi Jack,

a. You need to use any sftp software to take the backup of existing cluster by using DRS .

b. Build the new servers on same version first.

c. Check for DB-replication on new cluster so that DB is in SYNC .

d. There is no point of restoring since the new servers [TFTP and SUB]  would be on same version

e. If PUB and Old SUB  is build on new hardware , then, u need to restore the backup.

regds,

aman

[jones.jack]

thanks for help , i know all of backup and restore no problem . Firstly , i will have new h/w for the new cluster UCS servers ok , my questions are

How can i configure 7 servers , in my cluster ?. I will restore backup configuration for the old system and restore to the new for pub , what about other 6 servers and in setup as you know it asked about the role, for TFTP (i will configure it as pub or sub ) , i need your help please ?.

Thanks

[Chris Deren]

Restore publisher only, add all additional servers as new nodes and start appropriate services per your design.

Build CUCM Groups appropriately to utilize either 1:1 or 2:1 redundancy model as descried in SRND (no other model is supported even though many, many folks do it). Decide which site will use which CUCM group and assign properly to Device pools.  Dont forget other apps, such as UCXN, voice GWs, etc to reference these server's in their configuration.

HTH,

Chris

[jones.jack]

Chris

help me please , thanks for your post. My design will be for new 7 servers , i will use the configuration from the running system then  i will then restore configuration to my new pub , what about other six servers as you knew max number of serversin the cluster now are up to 8 servers . My issue after i add conf to pub , the other 6 servers what can i do for these?. I have one tftp server and other 5 servers , please guide me .

[jones.jack]

in your post you mentioned that group will be 1:1 or 2:1  , what can i do for other servers or what will be the role for the other servers?.

Thanks

[Chris Deren]

1:1 merely means that for each primary call processor you have dedicated backup.

2:1 means that a single backup server is designated as backup to 2 primary servers.

Lets assume you have 6 call processing servers all in single location, you would end up with following groups for example for 1:1 model:

Group 1: CM1, CM4, CM6

Group 2: CM2, CM5, CM4

Group 3: CM3, CM6, CM5

This all changes if your cluster is split between 2 data centers, where if you have 3 subs at each location you would probably go with 2:1 model such as:

Group 1: CM1, CM3, CM6

Group 2: CM2, CM3, CM6

Group 3: CM4, CM6, CM3

Group 4: CM5, CM6, CM3

HTH,

Chris

[jones.jack]

Very helpfull , what can we do without  chris!. For my case i have 7 servers in the same datacenter , so i will use as below 1:1, please advise

Group 1 : CM1(pub for call processing) ,CM2(sub for phone regiteration 7,500),CM3(sub for phone registeration,7500).

for the other 4 servers how can i use them?.

Thanks

[Chris Deren · Accepted solution]

I am assuming one of the 7 servers is the Pub, in which case I would not turn on CM service on it as for such large deployments it is not recommended/supported, thus the pub would not participate in call processing, hence no worry about CUCM groups for it.

The remaining 6 servers can be configured as following to get full usage of call processing/media recources/tftp/etc:

CM1 - Pub

CM2 - Sub primary call processor

CM3 - Sub primary call processor

CM4 - Sub backup call processor

CM5 - Sub backup call processor

CM6 - primary TFTP/backup media resource

CM7 - backup TFTP/primary media resource

Where your CUCM groups would look like this:

Group 1 - CM2, CM4, CM5

Group 2 - CM3, CM5, CM4

CM1, 6,7 would not have CM service running, hence would not be assigned as call processors.

HTH,

Chris

[jones.jack]

Hi Chris

that is what i need exactly . I need your help for the below

1- CCM 1 ,6 and 7 , no services (you means that the services will be deactivated , that do not access servicability for the both servers)?.

2- Can you give more details about configuration on  CCM6 and CCM7 ?.

3- For pub , i will only configure  my gateways , device pools , locations ,..... ?.

4- For my Cisco IP phones , which group will be join?. based on what

thanks alot

[Chris Deren · Accepted solution]

 1- CCM 1 ,6 and 7 , no services (you means that the services will be deactivated , that do not access servicability for the both servers)?.

Correct, do not activate the CM service, the CM service is responsible for call processing/registration, other service such as TFTP would be activated as normally

 2- Can you give more details about configuration on  CCM6 and CCM7 ?.

Server 6, 7 would have TFTP service activated and be referred to by your DHCP scopes under option 150, they would also have the IP Media Streaming App service started allowing software media resources such as MOH, Annunciator, Software CFB, MTP to be enabled. In your MRG/MRGL configuration you could prioritize server 7 over server 6  or load balance the load across them.

3- For pub , i will only configure  my gateways , device pools , locations ,..... ?.

You do not configure anything for Pub, Pub would be responsible for database processing, you could enable things like DNA, Extension Mobility, DirSync, etc on it.

 4- For my Cisco IP phones , which group will be join?. based on what

You load balance your devices which would include phones/GWs/media resrouces/etc between the 2 CUCM groups.

HTH,

Chris

[jones.jack]

Hello

Great thanks for you , i hope to summarize  what i will do :-

1-Create two froups.

2-Divide phones between two groups.

3-On pub (there is no conf , it will be for sync and DB replication).

so when i will take my backup conf , i will restore these conf on CCM2 or CCM3 . Please advise.

last question :

what about ccm 7 , if ccm 6 down ? how can ccm 7 be as backup and at the same time , it is not in the same group.

Thanks

[Chris Deren · Accepted solution]

Your summary is correct, when you will perform a restore you will need to reconfigure things. Here are the steps for that process:

1. Restore CUCM pub from backup

2. Add all subscribers to the cluster

3. Activate/deactivate services on all servers as outlined

4. Configure/change CUCM groups appropriately

5. Update device pools to reference proper CUCM groups

6. Update Voice GWs, other apps to reference new servers

7. Update DHCP scopes to point to new TFTPs

HTH,

Chris

[jones.jack]

Hello

last question :

what about ccm 7 , if ccm 6 down ? how can ccm 7 be as backup and at the same time , it is not in the same group. Backup configuration will restore on subscriber severs only or PUB also , please advise

Thanks

[Chris Deren]

CUCM 6 and 7 are not call processors, they are not part of any CUCM group.  They would have TFTP service running for pushing load/config files to phones and media resources such as MOH, so if one of them fails the other one can still provide TFTP services and media resources.

Remember a CUCM cluster can have up to 20 servers, but only 8 of those servers can be call processors, the remeining 12 could be Pub, TFTP, media, etc.

Chris