Multiple criteria based load balancing
This invention provides the ability to load balance calls in a communications network using a certain criterion, such as a user-specified call priority, or the call service category. The method is applied when selecting a route for a new call or for re-balancing the calls across a network. When the user-specified call priority is used, the aggregated number of calls with the same priority or service category is calculated for all possible routes the new call may use. The aggregated number of calls is then divided by the number of hops in the respective routes; the route with the smallest ratio is selected for the new call. Re-balancing is performed by re-routing the calls in such a way as to obtain a similar number of calls of the same priority, or service category along all possible routes.
1. A method of routing calls across a communication network with per-call load balancing, the method comprising:
identifying at least two possible alternate routes for a new call;
determining a first route performance value for each said possible route, for a call attribute corresponding to a bandwidth criterion;
determining a second route performance value for each said possible route, for a call attribute corresponding to a priority criterion;
determining a third route performance value for each said possible route, for a call attribute corresponding to a service category criterion;
selecting a route from the at least two possible alternate routes to carry said new call based on adding together said first route performance value, said second route performance value, and said third route performance value.
2. The method of claim 1 , wherein the determining of said first route performance value, said second route performance value, and said third route performance value occurs in a user-defined order.
3. The method of claim 1 , wherein determining the third route performance value further comprises:
counting for each link of said at least two possible alternate routes a number of calls-in-progress that have said call attribute;
calculating an aggregated attribute by summing the number of calls-in-progress for said at least two possible alternate routes; and
determining said third route performance value by dividing said aggregated attribute to the number of hops along said respective possible route.
4. The method of claim 1 , wherein determining the first route performance value further comprises:
calculating an aggregated bandwidth by summing bandwidth consumed by all calls-in-progress along each link of said at least two possible alternate routes; and
determining said first route performance value by dividing said aggregated bandwidth to a number of hops along said at least two possible alternate routes.
5. The method of claim 1 , wherein determining the first route performance value further comprises:
calculating for each link of said at least two possible alternate routes a consumed link bandwidth by summing bandwidth consumed by all calls-in-progress along said link;
calculating a link bandwidth value by dividing said consumed link bandwidth by link bandwidth capacity; and
determining said first route performance value by summing said link bandwidth values for all links of said at least two possible alternate routes.
6. The method of claim 1 , further comprising:
re-routing a call-in-progress established along a current route across said network between a source and a destination to the selected route.
7. The method of claim 6 , wherein the re-routing of the call-in-progress is determined without considering any route performance values for said current route.
8. The method of claim 1 , further comprising:
assigning a weight to each route performance value based on user-specified preferences for each route performance value.
9. The method of claim 8 , further comprising:
assigning different weights to at least two of the route performance values.
10. A system that performs load balancing of calls in a communication network, the system comprising:
a routing module that selects a list of possible alternate routes between a user-specified source and a destination;
a load balancing criteria module that receives a configuration form from a user that specifies selection criteria used for load balancing;
a link attribute processing unit that receives the selection criteria from the load balancing criteria module and the list of possible alternate routes from the routing module;
a first aggregated attribute calculation unit that determines a first route performance value for the list of possible alternate routes for a call attribute corresponding to a bandwidth criterion;
a second aggregated attribute calculation unit that determines a second route performance value for the list of possible alternate routes for a call attribute corresponding to a priority criterion;
a third aggregated attribute calculation unit that determines a third route performance value for the list of possible alternate routes for a call attribute corresponding to a service category criterion; and
a route selector that selects a route for a new call from said list of possible alternate routes, based on adding together said first route performance value, said second route performance value, and said third route performance value.
11. The system of claim 10 , wherein each of the aggregated attribute calculation units assigns a weight to each route performance value based on user-specified preferences for each route performance value.
12. The system of claim 11 , wherein different weights are assigned to at least two of the route performance values.
13. A system that performs load balancing of calls between a source and a destination within a communication network, the s stem comprising:
a routing module that selects a list of possible alternate routes between said source and said destination;
a load balancing criteria module that receives a configuration form from a user that specifies selection criteria used for load balancing;
a link attribute processing unit that receives the selection criteria from the load balancing criteria module and the list of possible alternate routes from the routing module;
a first aggregated attribute calculation unit that determines a first route performance value for the list of possible alternate routes for a call attribute corresponding to a bandwidth criterion;
a second aggregated attribute calculation unit that determines a second route performance value for the list of possible alternate routes for a call attribute corresponding to a priority criterion:
a third aggregated attribute calculation unit that determines a third route performance value for the list of possible alternate routes for a call attribute corresponding to a service category criterion;
a scoring unit that provides a route score, based on adding together said first route performance value, said second route performance value, and said third route performance value for each route in the list of possible alternate routes; and
a route selector that selects a route for a new call to be routed between said source and said destination, based on said route score.
14. The system of claim 13 , wherein each of the aggregated attribute calculation units assigns a weight to each route performance value based on user-specified preferences for each route performance value.
15. The system of claim 14 , wherein different weights are assigned to at least two of the route performance values.