Carriers around the United States have relied on the DCO as a Class 5 central office for more than 20 years and as a long distance switch for more than 15 years. Some 2,000 DCOs have been deployed as carriers have discovered its high reliability and cost effectiveness. Siemens EWSD is the most successful digital switching system worldwide. Over 280 million EWSD-switched ports across the globe make Siemens the number one supplier for carriers in this segment.

Comstock Telcom specializes in central office and transmission equipment, provider of new, reused and refurbished telecommunication products.