Metro Line Direct Coupon, Deals, Coupons, Vouchers + Promo Codes. Metroline Direct is one of the country's largest independent distributors of technology and telecommunications equipment. All New Aastra, Avaya, Cisco, Grandstream, Nortel, Mitel, Toshiba, NEC, Panasonic, Polycom, ShoreTel, VTech, and Yealink products are backed by MetrolineDirect's Rock Solid One-Year Warranty and 90 Day Advance Replacement Service.