How to configure Zenoss to send an SMS or Voice alert

Yes, Zenoss can do this using event mappings. Basically, you tell Zenoss to suppress events from certain "child" sources if a designated "parent" source also have active events.

There's a short explanation on the Zenoss community wiki, here:

• http://community.zenoss.org/docs/DOC-3215.

A common example scenario is remotely monitoring a site with several monitored severs accessible only via a single gateway. If the gateway dies, the servers behind it will be unreachable, and Zenoss will generate events for unresponsive gateway and all of the servers. In this case, the gateway would be a "parent" of the server "children", and an unresponsive-gateway event will cause Zenoss to suppress the unresponsive-server events.

Be sure gammu itself is reading from a right device path, and your user profile is in dialout group.

You may need to adjust bitrate to communicate to the module, so try to initiate direct communication using as example screen /dev/ttyUSB0 115200 and see what value fits at best.

The tool gammu-detect is also available, for spotting an initial configuration with a device, so man gammu-detect for more info.