Basic Automatic Route Selection (BARS) / Network Alternate Route Selection (NARS) is used to prevent users from placing unauthorized toll calls, and to route outgoing calls over the least expensive facility available at the time the call is placed.
There are lots of twists and turns on this journey! The following flowchart shows the process...
Use the cursor keys, or click page corner, to turn pages. Source: Nortel Training Material.
A user dials the BARS access code, AC1 (9), followed by a number:
- BARS tries to match (a portion of) the dialed digits in the tables
- If a match is found, a route is determined for the call
- FRL (NCOS) is checked (and optionally TGAR)
- Digit manipulation is applied (if necessary)
- If a trunk is available, the digit string is sent.
If any of the above steps fail, the caller hears re-order (fast-busy).
LD 86 - FEAT: ESN
LD 87 - FEAT: NTCL
LD 90 - FEAT: NET
LD 86 - FEAT: RLB
LD 86 - FEAT: DGT