The term Data CommunicationChannel (DCC) is used in Sonet and in the SDH hierarchy
for an inner-band channel. Each SDH frame contains two Data Communication Channels, referred to as Session-DCC and Line-DCC. These two DCC channels are used to transmit management messages between Network Elements (NE) or between Network Elements and the management system. The DCC channels allow the Service ProviderOperating Support System (OSS) to manage the SDH Network Elements without a separate out-band network.