VCS Control And VCS Expressway Calling with CallManager

OK, I think I found every stupid configuration mistake a person could make, mainly because of my lack of experience with this product as well as documentation which I feel isn’t as detailed as it needs to be, at least not for me.

1. You will have a “Neighbor” zone pointing to CallManager configured on the Control node. This is the counterpart to the SIP trunk on CallManager. Make sure you change the TCP port on the CallManager SIP Security Profile to something different than 5060 and match that with the SIP Port in the Zone configuration on the Control node.
2. Search rules are evidently analogous to router patterns. Create one with the “INTERNAL” domain of your SIP clients. This will route Internet Calls to the CallManager. I ran into a nasty issue that cost me a lot fo time. But in CallManager there is an Enterprise parameter on how Directory UIR matching is conducted, the default is case sensitive. I changed that as the first letter of my first and last name were capitalized in the Directory, hence I wasn’t able to dial all lowercase until I figured this out. Also set the “Target” field to the CUCM Neighbor zone.
3. Now my big mistake was, I created a DNS matching zone, but again, not understanding the product I created it on the Control node assuming it would push the config to the E-Node, which is NOT the case. And the result was truly confusing.
   1. First strange thing was that inbound calls would work fine.
   2. Second strange thing was that outbound calls would connect, but with no audio/video. After looking at traces and wireshark captures I discovered the Jabber client on the inside was using the public address of the remote end instead of the VCS C-Node, and there was no incoming audio packets. Once I deleted the “DNS” zone on the C-Node and created it on the E-Node, it worked as expected.
4. On the C-Node, I created a search rule for any alias, set the source name to the CUCM Neighbor zone, and set the Target as my TraversalZone I’m using for MRA.
5. As mentioned previously, I created a zone on the E-Node named Internet, set the transport to UDP, Type to DNS and the Zone Profile to Default.
6. I then created a Search rule with Source of “TraversalZone”, Mode of Any Alias and Target of my “Internet” zone.

All of my call flows for MRA and URI dialing to the Internet appear to be working with the one nagging issue that on outbound calls, CallManager uses its IP address in the source URI, which prevents people from being able to call directly back. I have created Transforms to try and correct this but they don’t seem to be matching at this point, so still an issue that’s on my plate.