Rather than making things harder set up these two SPN's and you will be all set
SPN 911
FLEN 4 -> This is the IMPORTANT part, this tells the PBX how many digits to expect before seizing a trunk i.e, 9+911.
ITOH NO
RLI 3 --> Your local (or dedicated 911) RLI
--> The following tells the PBX NOT to process calls that include any of the following digits AFTER the FLEN is exceeded.
DENY 0
DENY 1
DENY 2
DENY 3
DENY 4
DENY 5
DENY 6
DENY 7
DENY 8
DENY 9
SDRR DENY CODES = 10
ITEI NONE
This is the one some folks forget about, you NEED to allow calls to 911 to go even if the caller forgets to dial the access code i.e, 9 for the outside world. To allow for this requires that your RLI points to a DMI (digit manipulation index) which will take the SPN of 11 and add a 9 to it, so that the central office is presented with a 'real' 911 dial string to process.
SPN 11
SPN 11
FLEN 3
ITOH NO
RLI 5
DENY 0
DENY 1
DENY 2
DENY 3
DENY 4
DENY 5
DENY 6
DENY 7
DENY 8
DENY 9
SDRR DENY CODES = 10
ITEI NONE
This may be common practice for many of you but yours truly was not originally set up this way and only after a bad modem string (number entered 1-847-xxx-xxxx, comm software told to dial 9+1 switch & CO sees 911-847-xxx-xxxx) causing calls to PSAP did I realized where the problem lied.
Hope this helps!!!!
