Since December of last year, LMR personnel have been tracking down an open squelch problem coming across the San Francisco Divide control node on the Gila NF radio system. This problem has been intermittent. Replacement of radio modules and installation of channel banks offered no help to the problem. New Mexico techs ordered and received new Digital Signal Processors to be installed this month as a possible solution to the problem.
Last week(4/18), a major audio degradation issue was brought to LMRs attention from Gila Dispatch. At first LMR thought this may be part of the ongoing squelch issue or an issue with a recent Moducom dispatch console upgrade. Further analysis found this to be a completely different issue. On Thursday the 19th LMR dispatched two technicians to the Gila for troubleshooting.
Testing on the 20th revealed this issue was a network routing issue and continued working with network technicians to fix the problem. LMR technicians had several conversations with network and radio personnel the evening of the 20th and on the 21st. From those conversations, it was learned that a new router was installed to replace a failed router on the Gila. Over the previous week or so telephone systems failed with the replacement of the failed router. Telephone communications was normalized however, radio systems across the forest began failing more often with complete loss of communications across many control points.
As it turns out, the new 4300 series Cisco router lacked the proper IOS to provide tagging for radio audio and therefore proper Quality of Service required for radio communications was never accomplished. LMR was notified by network that the same issue was experienced on the Uinta Wasatch Cache.
Yesterday evening a 3900 series Cisco router with a IOS version that provided proper Quality of Service was installed, this normalized radio communications across the forest. The Gila did experience a short incident the morning of the 26th, which was the result of an major AT&T outage. Radio audio is routed through AT&T. All radio communications once again normalized as AT&T resolved their network failure.
In addition, with the replacement last week of the failing digital signal processor, we have not experienced any intermittent squelch issue across San Francisco Divide. |
