Redundancy in dial pattern CUCM 8.6 using SRST and Extension Mobility

[Kleber Rodrigues]

Hi,

I have a cluster with 3 CUCM 8.6 using SRST to many sites and extension mobility for users in each site.

So, i just configure to use Call Forward when unregistered to dial through PSTN, so when CUCM can´t see a station online will try alternate way to reach this station.

If a user is logged off, his station will be unregistered and CUCM will try to conect by PSTN, even if it could make this call by low cost voip dialpeer.

So, how can i configure to do this call forward and test if local router could make this call by wan and if the wan is down, make this call by pstn?

[mgbrown007]

Hello Kleber, Can you clarify some details of your design please?

1. Do you have 3 CUCM clusters, or 3 servers in a single cluster?

2. You mentioned "even if it could make this call by low cost voip dialpeer." How are calls being routed between sites with dialpeers?  Are all IP phones on the same cluster or do you have multiple registration points?

-mb

[Kleber Rodrigues]

Hi mb,

We have 1 cluster with 3 cucm(1 Pub and 2 subs).

We have central location and multiple routers in many sites. In remote site, phones are registered to CUCM in Headquarter and when wan link is down, these phones register at remote router with SRST fallback mode.

At headquarter, we dial station number in 4 digits format.

When remote phones are in SRST fallback mode, we have CFUR change the 4 digits format to output to PSTN using external digits format. But, also, when WAN link is up and a user profile is logged off and his station is unregistered, a call to this station is forwaded to PSTN and external digits format, with high cost.

We need a way to identify if the wan is up and phone is unregistered because the user doesn´t log on and sent this call by voip and if the wan is really down, sent by pstn, changing the output to external digits format.

I have an idea to use this by dialpeer at HQ router, after CFUR sending this call to the router, but i don´t know how to see if the remote router is accessible by wan or not.

Thank you...

[Ayodeji Okanlawon]

Kerber,

What you can do is thiss..

1. Add a prefix to all yur CFUR calls..eg 55, so if the destination is 7775000, yur CFUR will be 557775000

2. Create a new Route group, add the remote gateway and the PSTN gateway. Set the algorithm to to down

3. Create a new RL and add this RG to it

4. Create a new route pattern eg 55.! assign this route pattern to the new RL

5. on the SRST gateway cnfigure translation rules t strip the prefix 55 and then route ithe call as you  like

6. Do the same as 5 above on the PSTN gateway

Now when the user logs off, CUCM will send the call first to the WAN gateway, when the WAN gateway is down, CUCM will know and send the call to the PSTN gateway...You may need to change some parameters on cucm if you are using ISDN link on the remote router so that CUCM will route the call t the PSTN gateway when the ISDN goes down..If you CUCM looses ip connectivity to the remote gateway, this will work as it is

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[Kleber Rodrigues]

Hi aokanlawon,

I´ll do this config next friday, because we have a holiday and post a response here after this

Thank you!