This section describes the basic concepts related to data communication network (DCN).
DCN
A data communication network (DCN) provides communication channels for the NEs that are managed in a centralized manner to operate and maintain the NEs remotely. From a broad sense, a network for data communication can be called a DCN. In this document, the DCN refers to a data communication network for network management in the transmission domain.
ECC
An embedded control channel (ECC) implements operation, administration, and maintenance (OAM) communication between NEs. An ECC is a logical channel for communication between NEs and it is carried on a physical channel such as a data communications channel (DCC) or general communication channel (GCC) to transmit communication information between NEs.
DCC
A DCC is used to transmit OAM information between NEs. The DCC of Huawei's NG WDM products uses the D1 to D12 overhead bytes in an E1 frame defined in ITU-T G.703 to transmit OAM information.
GCC
A GCC is also used to transmit OAM information between NEs. The GCC of Huawei's NG WDM products uses GCC overheads in a protocol frame defined in ITU-T G.709.
DCN communication can be implemented using the HWECC, IP over DCC, or OSI over DCC protocol.
HWECC Protocol
HWECC is a Huawei proprietary protocol stack. It is the most applicable and advanced ECC communication solution for Huawei transmission devices. The HWECC protocol stack distinguishes NEs by ID and creates routes automatically. Because of this feature, the HWECC protocol is easy to use. However, the HWECC protocol cannot interwork with a network-level protocol on third-party devices. In general, it is used when only Huawei devices are used on a network.
IP over DCC Protocol
Huawei's IP over DCC uses DCC or GCC channels to transmit TCP/IP protocol packets. Like the HWECC protocol, IP over DCC is used to implement communication between NEs. The difference between them is that IP over DCC transmits IP protocol packets using DCC or GCC bytes but the HWECC protocol transmits Huawei-developed protocol packets using DCC or GCC bytes. Because IP over DCC uses the standard TCP/IP protocol, it can interwork with a network-level protocol on third-party devices, facilitating network management.
OSI over DCC Protocol
Huawei's OSI over DCC uses DCC or GCC channels to transmit OSI protocol packets between Huawei transmission devices and third-party devices that support OSI over DCC. Compared with HWECC and IP over DCC, OSI over DCC is more complex and difficult to configure.