We support a 911 center that uses two 2901 routers running ver 15.4 (3)m3 Release (fc2). Each one has a PRI to Century LInk. When calls are placed from an 911 position to the PSTN, "occasionally" the caller sees the onscreen message "ISDN PRI circuit did not respond. Trying alternate path #1",2,3,4" etc until all paths have failed. Then the call is pushed out via a pots line. Troubleshooting has shown calls refused by the PSTN. Century Link has been of no help. Is there a known bug related to this ver of IOS?
Thanks in advance
