Cisco Unified Presence DNS SRV

[Ruud van Strijp]

Hello,

I was trying to implement DNS SRV usage for CUPS. However, I just found out it uses the SRV record in the domain that your workstation is connected to. This causes issues for many of us I think, since we usually use 'companyname.local' as internal DNS and 'companyname.<country>' as external DNS. This external DNS is also what we use for our SIP domain, since that way the SIP addresses match our email addresses.

The main issue with this is that we have quite some people that work remote and are not joined to our domain.

Isn't there a way to resolve the CUPS server based on the SIP domain of the user? Basically, this his how Lync does it. So I would log in with username@domain.com, and then CUPS would look up the DNS SRV record for _cuplogin._tcp.domain.com instead of domain.local.

Sincerely,

Ruud van Strijp

[Jonathan Schulenberg]

The CUPC client just uses the DNS suffex of the workstation to build  the DNS SRV query. This method isn't going to work well if the user is  outside the network. Note that current CUPC releases are not intended to  run outside the firewall and require a VPN connection (e.g.  AnyConnect).

From the release notes:

Cisco Unified Personal Communicator contains a feature for the automatic discovery of Cisco Unified Presence servers. Previous versions of Cisco Unified Personal Communicator required either the administrator to push the server address to a client through a registry key or the client to manually enter the server address on the logon screen. Cisco Unified Personal Communicator can now use DNS SRV lookup to automatically find the Cisco Unified Presense server in the client's Active Directory domain.
DNS SRV is a record an administrator adds to a DNS server. This record can be added to any DNS domain but its addition to the Active Directory domain is recommended. A DNS SRV record is unlike a typical DNS record. Instead of storing a simple Host name and IP address pairing, DNS SRV records details about a particular service on a network. A DNS administrator can map many hosts to the same service name and assign a priority and weighting to each. This provides support for load balancing and failover services.
Cisco Unified Personal Communicator uses the following logon process when making use of the DNS SRV feature:
1. Application start up.
2. Local cache file is checked for server address.
3. If the cache file does not have the address, the local registry is checked for the server address.
4. If the local registry does not have the address, a DNS request is made against the connection specific suffix. If that fails the default Active Directory domain is queried. If the registry is populated, a DNS SRV request is made against the value in the registry. If the registry is populated and the DNS SRV request against the registry value fails, the registry value is put into the Login Address field in Cisco Unified Personal Communicator.
Cisco Unified Personal Communicator continues to support server identification through a registry key pushed to the client or manual entry.
Refer to the section Automatic Server Discovery in Chapter 13 of the Deployment Guide for Cisco Unified Presence Release 8.6 for additional information on configuring this feature. This section is available at the following location:
http://www.cisco.com/en/US/partner/docs/voice_ip_comm/cups/8_6/english/install_upgrade/deployment/guide/deploy.html#wp1102338