For on-premises deployments, Cisco Jabber clients on the corporate network use a DNS SRV record to automatically discover their home Cisco Unified Communications Manager (UCM) cluster. The primary method is to query for the User Data Service (UDS). The correct SRV record format is cisco-uds.tcp.. This record resolves to the UCM server(s), allowing Jabber to retrieve its service profile and configuration files, which include details for all other services like IM&P and the settings for the encrypted SIP profile (which uses TLS). This initial UDS discovery is the foundational step for Jabber to become operational.

A. DNS SRV query sip.tcp.domain.com: This is a standard SRV record for unencrypted SIP services, not the primary UDS-based discovery method used by Jabber to find its home cluster.
B. DNS SRV query cisco-uds.tls.domain.com: The protocol specified for the UDS service discovery SRV record is tcp. The tls protocol is not used for this initial lookup.
D. DNS SRV query sip.tls.domain.com: This SRV record is for Secure SIP (SIPS/SIP over TLS). Jabber uses this information for SIP registration after it has successfully completed UDS discovery and retrieved its configuration.

1. Cisco Jabber 12.8 Deployment and Installation Guide

"DNS Configuration" section: "For automatic service discovery

you must configure a Service Location (SRV) record in your DNS server for each domain... The SRV record that Jabber clients query is cisco-uds.tcp.example.com." This document explicitly states the required SRV record for internal service discovery.

2. Cisco Collaboration System 12.x Solution Reference Network Designs (SRND)

Chapter: "Cisco Jabber

" section "Service Discovery": "For on-premises deployments

the service discovery process starts with a DNS query for an SRV record of the form cisco-uds.tcp.." This confirms that cisco-uds.tcp is the standard for on-premises discovery.