Topic Last Modified: 2011-04-28

Devices use Domain Name System (DNS) to determine the address of the server that is running the Device Update Web service, which is hosted on Web Services. For internal communications, the Web Services IP address must be available in DNS, as must the SRV record for SIP. For details, see Setting Up DNS for Devices.

The device uses DNS to find the SIP domain portion, by querying the SRV record. The SIP domain is extracted from the resulting fully qualified domain name (FQDN), and ucupdate S-R2 is prepended. If the device is internal, :443/requesthandlerInt/ucdevice.upx is appended. If the device is external, the hardware load balancer should replace the port 443 with port 4443.

Device Cannot Find the Device Update Web Service by Using DNS

Issue: While it is not a critical problem if the Device Update Web service cannot be found by using DNS, the device will log on and then use the in-band value to locate the service. If the update itself is something critical to successful logon, this can result in device connectivity failures.

Note:
Devices that log on (for example, Polycom CX 700, CX600, and Aastra 6725ip) use the in-band value to create the service. No other devices logon and reply on DNS to find the update service. If the device cannot be located using DNS, then the device will not get upgrades.

To determine whether the Device Update Web service can be accessed, open a web browser and navigate to the appropriate URL: http://ucupdate S-R2.<SIP domain>:443/requesthandler/ucdevice.upx. If the site cannot be located, an HTTP 404 error page will appear.

Resolution: Check that the correct records are published in DNS. For details, Setting Up DNS for Devices.

If there is a missing or incorrect DNS record, resolve this. If this is an external connection, wait for a few minutes for this to be replicated to the appropriate DNS forwarders. Restart the device so that the cache is flushed. The device should restart and locate the Device Update Web service correctly.