Verizon Communications Inc. reached a network traffic deal with a longtime antagonist, avoiding a possible conflict in an area regulators are now eyeing more closely. The multiyear interconnection deal under which Verizon will swap traffic with Internet wholesaler Cogent Communications Holdings Inc. comes a week after Verizon announced a similar agreement with Level 3 Communications Inc. The moves allow Verizon to head off the sorts of high-profile fights with other carriers that made headlines last year when it pressed to be paid for carrying heavy traffic.