How does CUPC determine presence address

In order for CUPC to receive presence information, it has to connect to a presence node.

Just to remind you again, "presence node" is NOT necessarily the same node as the logon server. For example, you have two CUPS servers - CUPS-A and CUPS-B. The logon server could be CUPS-A, but the "presence node" could be CUPS-B.

Even in a single-node environment, CUPC still has to run through a set of rules to determine the "presence address".

If you ever looked at CUPC > Show Server Health (or CUPC logs), you'll notice two parameters: "Presence.Primary.Address" and "Presence.Domain".

"Presence.Primary.Address" is the node name of the server. You may find this under CUPS Admin > System > Servers.

"Presence.Domain" is the SIP proxy domain. You may find this under CUPS Admin > System > Service Parameters > Cisco UP SIP Proxy.

If the node name was configured as dotted IP address (e.g. 192.168.1.100), CUPC will use that as the presence address.

If the node name was non dotted IP, things are more complicated. Here are the rules CUPC uses to determine the presence address:

When you specify a non IP string for the node name, CUPC looks at the string to see if it already ends with the domain value -- if not, it appends it. Examples:

1)
Proxy.Domain = cisco.com
Presence.Primary.Address = cup1

Registration will be to user@cup1.cisco.com (hostname, domain is appended)

2)
Proxy.Domain = cisco.com
Presence.Primary.Address = cup1.cisco.com

Registration will be to user@cup1.cisco.com (FQDN, domain was already included)

3)
Proxy.Domain = cisco.com
Presence.Primary.Address = 10.11.12.13

Registration will be to user@10.11.12.13 (address was dotted-decimal)

4)
Proxy.Domain = 10.11.12.13
Presence.Primary.Address = 10.11.12.13

Registration will be to user@10.11.12.13 (address was dotted-decimal)

5)
Proxy.Domain = 10.11.12.13
Presence.Primary.Address = cup1

Registration will be to user@cup1.10.11.12.13 (hostname, domain is appended) WRONG

6)
Proxy.Domain = 10.11.12.13
Presence.Primary.Address = cup1.cisco.com

Registration will be to user@cup1.cisco.com.10.11.12.13 (FQDN, domain is appended) WRONG

7)
Proxy.Domain = PROXY_DOMAIN_NOT_SET
Presence.Primary.Address = cup1.cisco.com

Registration will be to user@cup1.cisco.com.PROXY_DOMAIN_NOT_SET (FQDN, domain is appended) WRONG

The last 3 of these are wrong (there are other permutations) because the domain portion of the URI is neither an IP address nor DNS-resolvable FQDN. While the proxy might be content to match the strings, CUPC's SIP stack needs to resolve to a routable address.

Please note everything is case sensitive. If node name was cup1.cisco.com, proxy domain was CISCO.COM, presence address will be "cup1.cisco.com.CISCO.COM", which is also WRONG.