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If you get 2 or more SIP Trunks from the same ITSP provider, you can setup a load balancing list using the same rate list.
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In the Load Balancing SIP Trunk List "SIP_Trunk_List_C", there are 2 resources: SIP Trunk C1 and C2 and you can set their "weight" to decide which one will be used more often.
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