Routing

Overview

LibreSBC provided a powerful built-in routing engine which allows to selects an destination entities (outbound interconnection) for an inbound call based on one/multiple session criteria/variable. The Routing Engine can serve for most of use case in real life include:

• Inbound Classify
• Block Traffic
• Jumping routing plan
• Diversity routing criteria with engine variable
• Various Matching type: Longest matching prefix, Exactly match, Comparing
• Load Distribution: Fail-over, Load Balancing, Percentage Load
• Flexible by Manipulate/Translation

Routing Table

Routing table is key element of data for routing engine, It define the fundamental schema of routing. It must be assigned to an inbound interconnection to take effect and can be reuse many time if needed. These following parameters can be declare in routing table:

Parameter	Category	Description
name	string required	The name of routing table
action	enum required	The action for routing, include route, block, query. Default is query route go directly to destination interconnection that defined in routes map object. block block traffic query do the query route via routing records with variable criteria.
variable	string	The name of engine variable that will be configure value in routing record. Applicable only action is query.
routes	map	Route Map Object. Applicable only action is route.

Routing Record

Routing Record is unit element of data for routing engine, It define the way how engine examine the rule to select the next destination. Routing record has various matching type, and action as well as value to support engine select property next-hop. These following parameters can be declare in routing record:

Parameter	Category	Description
table	string required	The routing table name the routing record belong to
match	enum required	The matching type that will be define criteria to select. {eq, ne, gt, lt}: compare matching em: exactly match lpm: longest prefix matching
value	string required	The value can be present by two purpose: → The fixed value of variable that already defined in routing table (lpm em) → Name of other variable for compare (eq, ne, gt, lt) DEFAULT_ENTRY is value alias for default records, its similar to default route (0.0.0.0/0) in network routing table.
action	enum required	The action for routing, include route, block, jumps. Default is query route go directly to destination interconnection that defined in routes map object. block block traffic jumps jumps to another routing table
routes	map	Route Map Object. Applicable only action is route.

Comparing matching Note

• eq: equal to
• ne: not equal
• gt: greater than
• lt: less than

Routes Map Object

The routes may be used by both table (applicable with route) and record (applicable with jumps & route), it is quite simple but flexible enough for load sharing and refer to use another routing schema in particular condition.

Parameter	Category	Description
primary	string required	outbound interconnection routing-table The primary route
secondary	string required	outbound interconnection routing-table The secondary route
load	int required	0-100 Distributed value of load sharing between primary and secondary. eg: load=100 mean 100% call will use primary as route, only failover to secondary if primary is down. load=50 mean load balancing between primary and secondary.

Example:

Suppose that We have:

• Three telcos Orange, Docomo and VNPT connect to LibreSBC as outbound interconnections
• The Core-Component (your PBX, Contact Center, etc)

And here is requirement:

1. Outbound call from Core-Component to France (+33) will use Orange, if Orange failure fail-over to Docomo
2. Outbound call from Core-Component to Japan (+81) will use Orange and Docomo load balancing
3. The rest of Outbound call from Core-Component will use VNPT.

Solution:

routing table

{
  "name": "default",
  "desc": "example routing",
  "variables": [
    "dstnumber"
  ],
  "action": "query"
}

routing record

{
    "table": "default",
    "match": "lpm",
    "value": "+44",
    "action": "route",
    "routes": 
    {
        "primary": "Orange",
        "secondary": "Docomo",
        "load": 100
    }
}

{
    "table": "default",
    "match": "lpm",
    "value": "+81",
    "action": "route",
    "routes": 
    {
        "primary": "Docomo",
        "secondary": "Orange",
        "load": 50
    }
}

{
    "table": "default",
    "match": "lpm",
    "value": "DEFAULT_ENTRY",
    "action": "route",
    "routes": 
    {
        "primary": "VNPT",
        "secondary": "VNPT",
        "load": 50
    }
}