4.13 to 8.*
Basically what I want to do is build 8.* new CSS/PT use local RG's add some new features that this place has been lacking etcc....
So build the new cluster but I want to run it in pralell with the current cluster and migrate phones by building/site
Weekend 1 migrate Bulding 1
Weekend 2 migrate building 2 and so on
We have 4 bulidings in our local campus and 3 remote sites. All phones are in their respective DP's based on location BUT our phone numbers for example 555-666-XXXX reach across all of the 4 bulidings in the campus where 6XXXX is what the directory number would look like.
So if I were to run the systems in paralell obviously I would trunk them and thats where the question comes in.. how would I route calls across the trunk if 6xxx is acorss all 4 sites? Would it come down to the CSS/PT's ?
Each location has it's own gateways for inbound and outbound
You will have to pick with cluster will be front ending the PSTN and then route the calls across the trunk, so lets assume you leave your 4.1 system as the one connected to GW (PSTN), when calls come into the cluster they will either match a DN assigned to a phone on this cluster and route to it, or they will need to route across the trunk to the other cluster. You can simply build a wildcard route pattern such as 6XXX that points to the other cluster and serves as a "default route", you will need to add this pattern to a partition that is reachable from the ingress GW's CSS.
You have to be creful not to create infinite loops (even though CUCM can handle that) by not having a similar open route on the new cluster back to the 4.1 cluster. What I normally do is build explicit route patterns for the DNs that are still on the old cluster.
Of course you can reverse the logic and build 6XXX on new cluster and explicit patterns on old cluster that point to new.
When phones are migrated to the new cluster I plan to add the gateway of that building to the new cluster also. So inbound calls to that phone should not be a problem. Each buliding has their own GW for inbound and outbound
So I'm more talking about the internal calling
From Site A on ccm 4.13 with an extension of 61234 to Site B on the new cluster with an extension of 61254
Sorry, missed that on your intial post.
But the same logic applies, one side can have 6XXXX pointing to the other side, and the other side would have explicit route patterns such as 61234, etc to avoid hairpining. If both clusters were CUCM 8.5+ you can do SIP trunks with QSIG which would avoid tromboning and both sides would be able to have 6XXXXX.