Extension mobility redundancy in CUCM 8.5

[baskaranm]

                   Hi ,

I have a doubt in cucm 8.5 extension mobility redundancy.

I have 3 call managers in cluster.

1. X.X.X.1 - punlisher

2. X.X.X.2 - sub1

3. X.x.X.3 -  sub3

i have configured CUCM X.X.X.2 (sub 1) for extension mobility URL and in exterprise parameter configuration also (service URL). all phones are subscribed this URL and users login.

my schenerio is,

if SUB1 goes down, i change enterprise parameter service URL IP to punblisher. is that enough for users to login to extension mobility?

my doubt is,

in the above schenerio,

users press services button, request will go to enterprise parameter URL> enterprise URL will check for subscribed services> and route the request to the subscribed services for the phones . but here i have subscribed only EM service which has sub1 IP address.

how user can login?

if users can login meas, how that works.

or do i need to create 2 EM service (one for SUB1 IP, another one for PUB IP) and subscribe all the phones with both the services?

so that if subscriber fails user will login another service with has publisher IP?

I have activated EM service in all call managers inthe cluster.

please clarify my doubts.

thanks

[Anas Abueideh]

Hi,

you need to a load balancer to configure redanduncy for EM. you need to activate the EM on all nodes and create virtual IP in the enterprise parameter.

HTH

Anas

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[baskaranm]

I;m not saying for automatic failover redundancy. I want for manual change in EM login.

[islam.kamal]

Hi

Yes , the extension mobilty HA is avilable starting from V8 .On earlier verions as v 7 is not supported, Please find the below link:-

http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/8x/cmapps.html#wp1189079

I think you have to deploy SLB (server load balancer) to distribute requests through servers . You can use load balancer as  (F5 , or DNS round robin).

Note:The problem , is that the "Login" and "Logout" service URLs can really only point to one IP address. Please find the below solution based on DNS:-

- create multiple DNS records for the same name which will point to two CCM servers running the EM service

- point your  EM service URL at that hostname which you have created on 1 step.

- ensure your phones have valid DNS servers assigned to resolve the above

Note: the problem on the DNS is the delay between requests.

Thank you

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[baskaranm]

Yes as you said we can point only one IP in the EM service URL. that why i configure 2 EM service wih different IPs(one with Pub IP  and another with sub IP,) . when sub fails I change IP in enterprise parameter ip to pub.

user will login by selecting another pub IP URL and login

[Anas Abueideh]

Hi,

the question is, what you will do if the pub fails and you want to change the enterprise paratmeters it will not changed

HTH

Anas

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[Aman Soi]

Hi ,

You can do EM redundancy by configuring SLB , below commands on Core Switch.

a. ip SLB probe TEST http

  request url /ccmcip/getservicesmenu.jsp

port 8080

b. ip slb serverfarm CUCM

probe TEST

c. real PUBIP

weight

inservice

d. real SUBIP

weight

inservice

e. ip slb vserver CCM-EM

virtual IP for EM tcp

serverfarm  CUCM

inservice

regds

aman

[Robert Thomas]

Baskaranm,

So you could remedy the issue changing the IP Address in case you have one of your SUB fail.

But if your PUB were to fail, and also any other SUB you loose the ability to make changes. Keep in mind your PUB is the only master/slave version of the Database.

Also on firmware 8.X I don't think a load balancer is that necesary anymore. If you use your service provisioning set to internal the phone will construct dynamic URLs pointing to the CUCM that you are registered at that time, if the EM service also runs in that server and it's accesible then you are able to login.

[baskaranm]

Hi Robert,

thnaks for your reply.

you mean to say if services provisioning parameter is set to internal and phones are subscribed with only one EM service,

if particular call manager (EM service URL IP - call manager) goes down, wothout changing anything still users can login?

services provisioning parameter is set to internal phones will get dynamic URL for which call manager the phone is registered and user can login is it?

[Anas Abueideh]

Hi Robert,

can you calrify more about

"Also on firmware 8.X I don't think a load balancer is that necesary anymore. If you use your service provisioning set to internal the phone will construct dynamic URLs pointing to the CUCM that you are registered at that time, if the EM service also runs in that server and it's accesible then you are able to login."

what do you mean by provisioning set to internal and how phone will construct dynamic URLs ?

regards

Anas

[Robert Thomas]

Anas,

Internal provisioning for EM will mean the URL will be dinamically set to the SUB you are registered. If your SUB goes down, the phone will failover and construct a new internal URL pointed to that specific SUB. Meaning your EM URL will always point to the SUB you are registered (which has to be online)

If the EM service is running on that same node, you will be able to login.

[baskaranm]

HI Robert,

I understand,

for extension mobility redundancy,

If we have call manager 8.X and extension mobility service running on all nodes, service provisioning is set to internal, we canlogin in case of any node failure .

My understanding is correct?

[Ayodeji Okanlawon]

I doubt if this will work,

Internal services  provisioning only applies to URLs that look like "Application:Cisco/"  such as "Application:Cisco/Directories" for corporate directory.  This  format tells the phone to contact the node which the phone is registered  to for load balancing/redundancy.  If the services provisioning is set  to internal but the URL is in the format http://.... then the phone will contact the server listed in the URL.

Please refer to similar threads here

https://supportforums.cisco.com/thread/2182810

https://supportforums.cisco.com/thread/2164102

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[baskaranm]

HI aokanlawon

SO I create EM URL service for all node IP address. I mean,

URL 1: with PUB IP address.

URL 2 : with SUB1 IPaddress

URL3: with SUB2 IP address.

and subscribe  phones with all 3 EM services. when one node goes down user will another node EM service and login.

with this I need to have Publisher online to change the Enterprise service parameter whenever reuired.

is that right?

[amansin74]

Hi Baskaranm,

I understood that you want to manually change URL in enterprise parameter.

For that to work You need to restart all IP Phones using that URL. This way IP Phones will download the latest URL from the enterprise parameters and work accordingly.

I do not think it will work without an IP Phone restart. Are you willing to go for that ? If not, you can go for Load Balancing as suggested above.

--

Aman

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