Breaking the keying loop between two simplex nodes

Back and forth keying (aka as "Ping Ponging" or "Relay Racing") can occur when two simplex nodes are linked together. This is caused by COR or squelch noise glitches from certain types of radios. To fix,the COR must be ignored for a small amount of time after a simplex node releases PTT. To accommodate this, edit /etc/asterisk/usbradio.conf and add the following statement in the [usb] stanza or other port-specific stanza:

rxondelay=25

This will instruct the usbradio driver to ignore the COR line for a specified number of 20mSec intervals following the release of PTT.