CUCM 8.6 Redundancy doubts

[etmarcof]

Hi,

If i have one CUCM 8.6 cluster  with two servers (on LAN)  and  let's say 200 ip phones (7960 and 7940 with Extension Mobility) and one Cisco  Gateway to PSTN in "H323 mode"  all registered with Subscriber.  Also one Business Attendant Console Server and one Client.

If CUCM publisher Fails:

- Regarding Extension Mobility if the EM service active was on publisher,  and if i don't have redundancy of ip phone services (DNS or SLB)

, can i logout loggedin profiles? (I suppose i can login new profiles using ip phone service link pointing to subscriber)

- Can i change configurations of  call forwards all/no answer /busy destinations?

If subscriber fails:

- If i have a call established from PSTN to ip phone  through  cisco H323 gateway  can i transfer that call after subscriber failed? Or  ip phone will only register on Publisher after call disconnects?

Regarding Business Attendant Console if publisher or subscriber goes down  Its necessary to login again or its "transparent"?

Best Regards

MC                

[Jaime Valencia]

No, you cannot logout phones without sending the request to the EM service.

You can only do CFA FROM the phone, no CCMAdmin nor CCMuser changes allowed.

Assuming you have the H323 GW with a CCMgroup with both servers, and the dial-peers pointing to both servers on the actual GW, you can still make/receive calls.

HTH

java

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[etmarcof]

Hi,

But if ip phones have to services of EM if use link of IP phone service that point to EM service in subscriber can i logout profile even if i logged in profile with  EM service of Publisher?

I know that i can make/receive calls from PSTN, i 'm talking about calls that are connected when subscriber goes down. It's possible in that calls for exampe make transfers?

Thanks

Best Regards

MC

[Ayodeji Okanlawon]

Hi,

The active call will stay connected because CUCM is not involved in streaming of RTP between end devices. Once the call setup is complete, CUCM is kind of out of the picture until the call is disconnected etc.

Once the call is completed, the ip phone can then re-register to its secondary server is there is any otherwise it will go to SRST.

Because supplementary services like transfer will involve signalling which cucm is responsible for, you may not be able to perform that while the active server to which the phone is registered to is down.

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"'Nature is too thin a screen, the glory of the omnipresent God bursts through it everywhere"-Ralph Waldo Emerson

[Gordon Ross]

Anything that involves a database change (e.g. EM Login/Logout) cannot be done whilst the publisher is down. All database changes have to go through the publisher.

There are some workarounds for minor things like setting CFwdAll, but that is the exception, rather than the rule.

Call handling should not be affected when the publisher goes down, providing the call doesn't need the publisher (e.g. an MTP or gateway that run exclusively on the publisher)

GTG

[etmarcof]

Hi Gordon,

I'm confused now, i suppose that from CUCM 6.x  and later i can activate EM service in Pub and also in Sub for redundancy.  so that i can login EM profiles in phone when pub is down isn't that true?

Best Regards

MC

[Ayodeji Okanlawon · Accepted solution]

Yes you can.

For EM services to achive resiliency, it is advised that you use some form of SLB (server load balancing) for both the IP phone service and the EM service. This usually will use a virtual ip for the services so that when one server is down, the other can take over automatically. This way your services will not be pointing to a fixed server ip but a virtual IP and through SLB, an available server will be selected.

You cannot use one server ip for login and another for logout.

Please refer to SRND for EM resiliecy configuration and desgin

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"'Nature is too thin a screen, the glory of the omnipresent God bursts through it everywhere"-Ralph Waldo Emerson