Outgoing Routings

This is the main section in which routing policies are defined.

These are the fields that define an outgoing routing rule:

Client
Should this rule apply to all clients or just to one specific client?
Routing Tag
Routing tags allow clients to call to the same destination through different carriers. This field makes the rule valid for just one routing tag (or for none).
Call destination
This groups allows selecting if this rule applies for just one destination pattern, for a group or for faxes.
Route type
There are two kind of rules: static and LCR. In static, only one carrier is selected. In LCR, multiple carriers may be selected.
Priority
If a call matches several routes, it will be placed using the outgoing route with lower priority, as long as it is available.
Metric
If a call matches several routes with equal priority, metric will determine the proportion of calls that will use one route or another.

Error

All clients rules apply to all clients, even if they have specific matching rules. Matching specific rules and global rules are merged when selecting a carrier for a given client.

Tip

If you want to achieve “Fallback for all clients” rules, make sure you use high priority values.

Warning

When placing a call to a given destination, rules with that pattern will be merged with rules of groups that contain that pattern.

Note

In all this rule merging process, priority and metric determine the order.

Note

Fax specific routes will apply first for both faxes sent via virtual faxing (see Faxes) or T.38 capable devices. If no fax specific route found, remaining routes will apply as for a normal voice call to that destination.

Last two fields, priority and order, are key parameters to achieve two interesting features too: load-balancing and failover-routes.

Load balancing

Load-balancing lets us distribute calls matching the same pattern using several valid outgoing routes.

Example 1

  • Route A: priority 1, metric 1
  • Route B: priority 1, metric 1

Call matching these routes will use route A for %50 of the calls and route B for %50 of the calls.

Example 2

  • Route A: priority 1, metric 1
  • Route B: priority 1, metric 2

Call matching these routes will use route A for %33 of the calls and route B for %66 of the calls.

Failover routes

Failover route lets us use another route whenever the main route fails.

Example

  • Route A: priority 1, metric 1
  • Route B: priority 2, metric 1

All calls matching these routes will try to use route A. In case the call fails, the call will be placed using route B.

Tip

Although given examples use two routes, more routes can be chained and failover and load-balancing strategies can be combined.

LCR routes

LCR (Least Cost Routing) routes may select more than one carrier. Whenever a LCR rule is used, the platform will compute the call cost for that given destination (for a 5 minutes duration) and will order them in increasing order.

Note

Carriers that cannot compute cost for a given destination are silently ignored (they are not used).

LCR and static rules combined

Carrier election process can combine static and LCR rules:

  1. Static rules result in one carrier with the priority and the weight of the rule.
  2. LCR rules result in n carriers, ordered by call cost, all of them with the priority and the weight of the rule.
  3. Carriers are ordered using priority (ascending order).
  4. Carrier’s weight is used for load-balancing between carriers with same priority.