A collaboration engineer is troubleshooting an issue with Cisco Jabber for Windows clients Users in a new branch location report that 'cannot locate…

The Cisco Jabber client uses a DNS-based service discovery process to automatically locate its home Cisco Unified Communications Manager (CUCM) cluster. The error "cannot locate server" indicates this discovery process is failing. For internal clients, Jabber queries DNS for an SRV record named cisco-uds.tcp.. This record points to the CUCM servers that provide the User Data Service (UDS), which is the first step for the client to download its configuration. Since manual configuration works, connectivity to the servers is fine. The issue is specific to a new branch, which strongly implies a localized DNS misconfiguration. Adding the cisco-uds.tcp SRV record to the branch DNS server will allow clients to automatically discover the CUCM servers and log in successfully.

A. Reinstall the Jabber clients with UPNDISCOVERYENABLED=false: This parameter alters which domain Jabber uses for its DNS query (email vs. User Principal Name). It does not fix the underlying issue of a missing SRV record in the DNS server.
B. Add a firewall rule to allow TCP/8443 from the branch to HQ: The fact that manual configuration works proves that connectivity on required ports, such as TCP/8443 for UDS, is already established. The error occurs before this connection is attempted.
C. Add a collab-edge Us.company com SRV record to the branch DNS server: The collab-edge SRV record is used exclusively for Mobile and Remote Access (MRA) discovery via Expressway for external clients, not for internal clients on the corporate WAN.

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

Chapter 10: Collaboration Edge and Mobile and Remote Access.

Section: DNS for Service Discovery

Content: "For automatic service discovery on the internal corporate network

Cisco Jabber clients query for the SRV record cisco-uds.tcp.... This SRV record should point to the CUCM nodes that run the UDS service." This directly supports option D as the correct mechanism for internal discovery. The same section also specifies that collab-edge is for MRA

invalidating option C.

2. On-Premises Deployment for Cisco Jabber 12.9

DNS Configuration.

Section: Create SRV Records for Service Discovery

Content: "To enable automatic service discovery for Cisco Jabber clients on the corporate network

you must configure a Service Location (SRV) record in your DNS server for each of your user's email domains. The SRV record maps the user's email domain to the Cisco Unified Communications Manager servers that are used for service discovery... Format: cisco-uds.tcp.example.com." This confirms the exact SRV record needed.

3. Cisco Unified Communications Manager Administration Guide

Release 12.5(1)SU1

Chapter: User Data Service.

Section: User Data Service

Content: This chapter describes the UDS API

which Jabber uses to access the user's home cluster and contact information. The service discovery process (cisco-uds SRV record) is the mechanism by which clients find the servers providing this essential service. This explains the central role of UDS in the login process.