I am wrapping up a UC deployment with CUC 8.6(2a). Overall, I’d say the platform is stable and no major issues were encountered.
However, there were a few notable experiences/lessons learned along the way that are worth passing on. Some of these experiences may be unique to the equipment I worked on. You are welcomed to verify these findings against your own environment.
Configuring SRV Records
A typical CUC SIP integration uses SIP trunks configured in CUCM, one for each Unity Connection server. Using route groups, you have some control in determining how calls are sent across the trunks.
The “Design Guide for Cisco Unity Connection Release 8.x” refers to SRV records as another legitimate deployment model. When I read this, I was pleasantly surprised. It seemed a reasonable way to remain consistent in my design since the CUPS integration was using an SRV.
When integrating with Cisco Unified CM through a SIP trunk, it is possible to balance voice traffic that the Connection cluster server pair handles by using one of the following methods:
- (Recommended) Use a Route List in Cisco Unified CM.
- Use DNS-SRV – RFC 2782.
- Use a SIP gateway DNS-SRV.
Using an SRV record, I could configure a single SIP trunk in CUCM (e.g. cucvm.domain.local), which would point to my Unity Connection servers. This would reduce the amount of configuration and make it easier for troubleshooting in the future.
I like the functionality of SRVs records. Unlike simple top down or circular methods (i.e. used in CUCM route groups), SRVs allow for the configuration of priority and weight. You could configure 70% of calls to use the CUC Publisher, for example; a function not allowed through CUCM.
I configured the SIP trunk in CUCM as cucvm.domain.local, just like a CUPS integration.
However, when I placed test calls to the voicemail pilot it failed. The traces verified that CUC was rejecting the call.
It appears that neither CUCM nor CUC are aware that this SRV record is being used for communication between clusters. Unlike CUPS, there isn’t a way in CUC (to my knowledge) to configure call routing by SRV.
Long story short, after opening a ticket with TAC, I found that the Unity Connection team had no idea that Connection could support (allegedly) SRV-based integrations with CUCM. Though the design guide mentioned SRV records, there was not one reference of this in the configuration or administration guides.
My verdict?
- Don’t bother with SRV records for Unity Connect right now. Though SRVs allow for more granular load balancing, a simple route list in CUCM will suffice for most customers.
- Cisco needs to determine if SRV deployments will be supported or not. If so, TAC engineers need to be briefed and configuration documents need to be updated. If not, remove the reference in the design guide to reduce confusion.
CUC 8.6(2) OVA Template
My current environment is running UCS B200 M2 series blades with Intel Xeon E5649 2.53GHz processors. When deploying the OVA template, it appears that the minimum CPU reservation defined is 6 Mhz higher than what vCenter allows.
The error: Could not power on VM: CPU min outside valid range.
This issue is still outstanding with TAC. If you are installing Unity Connection 8.6(2a) on a B-Series, I’d be interested to see if you experience the same issue. The OVA template being used: CUC_8.6.2_vmv7_v1.5.ova
