1. A method of routing voice communications, the method comprising: receiving network event data at a telephone number mapping server of an originating network from a plurality of peering border elements associated with a plurality of peering communication networks, wherein the network event data indicates a health status of each of the peering communication networks; determining a proportion of calls that are to be routed from the originating network via each peering communication network of the peering communication networks; and dynamically assigning order field values and preference field values within naming authority pointer records to session initiation protocol addresses of each peering border element of the peering border elements based on routing calls to a peering communication network associated with the peering border element in substantially equal to the proportion determined for the peering communication network.