Routing an outbound call is a 2 step process.
The Phone Port DigitMap validates the dialed number.
The last rule (Mpli) will include the rules in primary line's DigitMap.
If the dialed number doesn't match a rule, you will receive a fast busy.
If the dialed number matches a rule in the DigitMap, the phone port OutboundCallRoute will get control and route the call to the primary line using rule {(Mpli):pli}
If you want to route 911, you need to place a rule to the left of {(Mpli):pli}
My example placed the Line routing rule 1st, so 911 will only be routed to the OBi212/Line.
I assume you have a rule routing 911 to SP4. It will be ignored.
A trunk group is used to route a call to 1 or more additional trunks when the primary trunk fails.
You define a TG with a list of trunks
When the TG gets control, it will compare the dialed number to the DigitMap of the 1st trunk.
If there is a match, the call will be routed to that trunk.
If there is no match or the call fails, the TG will try the next trunk in the list.
The TG can be used for normal routing and not just failover
SP1 DigitMap: (1xxxxxxxxxx|<1>[2-9]xxxxxxxxx|011xx.)
SP4 DigitMap: (911)
SP4 X_NoRegNoCall: Checked
ITSP D SIP TimerB: 6000
VG1 DigitMap: (911)
Trunk Group1
Trunk List: sp4,vg1,sp1
DigitMap: ((Msp1)|(Msp4))
Phone1/2 Port
OutboundCallRoute: set it to default
PrimayLine: Trunk Group 1
Dial 911
The call is routed to SP4
If the call fails it will be routed to VG1
Dial 8005551212
The call will not be routed to SP4 because no match with SP4 DigitMap
Same with VG1
The call is routed to SP1
The TG will timeout after 32 seconds before failing over to the next trunk.
With X_NoRegNoCall it will failover immediately when the trunk isn't registered.
TimerB will change the timeout from 32 seconds to 6. This will prevent a long timeout when the trunk is down, but the OBi202 still thinks it's registered.
