The QoS settings over your link will not have any effect on the echo you are experiencing.
The two main factors involve in the generation of such echo are: 1. Delay on the PSTN. 2. Not enough Echo Return Loss. In other words, your outbound level into the PSTN is too high and probably your input level into the IP cloud is too high as well. You may want to tune the voice-port that goes into the PSTN by using input-gain and output-attenuation.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.