Outband DCN Overview

The element management system (EMS) sets up communication with NEs through a data communication network (DCN), to manage and maintain these NEs.

In a DCN, the EMS and NEs are both regarded as network nodes, which can be connected through Ethernet or physical data communication channels (DCCs).

In practical networking, the EMS and NEs can be located on different floors in a building, in different buildings, or even in different cities. Therefore, the connection between the EMS and NEs usually requires an external DCN that is composed of equipment such as LAN switch and routers. On the other hand, the DCN among NEs is referred to as an internal DCN. This topic describes the internal DCN composed of NEs. See Figure 1.

Figure 1 DCN network

External DCN

In general, an external DCN is a local area network (LAN) or a wide area network (WAN) and uses the Transmission Control Protocol/Internet Protocol (TCP/IP) or the Open System Interconnection (OSI) protocol for communication. It mainly provides communication between NMSs and communication between the NMS server and GNEs. The details are as follows:

Communication between NMSs
The communication between NMSs includes the following parts: communication between the NMS server and the operations support system (OSS), communication between the NMS server and clients, and communication between the primary and secondary sites in a high availability (HA) system. The NMS communication can be implemented only using the TCP/IP protocol.
Communication between the NMS server and GNEs
The NMS server and GNEs may be located on different floors of a building, in different buildings, or even in different cities. Hence, an external DCN that is comprised of the data communication devices, such as LAN switches and routers, is required to connect the NMS server and the GNEs. This type of communication can be implemented using either the TCP/IP or OSI protocol.
Usually the NMS server connects to GNEs in the following two modes:
- The NMS server connects to GNEs through Ethernet switches.
  This mode applies when the distance between the NMS server and each GNE is smaller than or equal to 100 m and no other Ethernet networks are available between the NMS server and the GNE.
- The NMS server connects to GNEs through routers.
  This mode applies when the distance between the NMS server and each GNE is greater than 100 m and an Ethernet network is available between the NMS server and the GNE.
NOTE:
The DCN communication between the NMS server and GNEs belongs to the data communication domain and therefore is not elaborated in this document. The DCN mentioned in this document refers to the internal DCN, unless otherwise specified.

Internal DCN

An internal DCN provides communication between NEs using the HWECC, TCP/IP, or OSI protocol. The protocol packets are transmitted over optical supervisory channels (OSCs) or electric supervisory channels (ESCs).

Introduction to the DCN
With the development of network scale, OAM of a network becomes more and more difficult. A stable and robust DCN management network helps lower the OAM cost.
DCN Solutions
The OptiX series equipment of Huawei provides multiple DCN solutions.
HWECC Features and Functions
To help the U2000 Web LCT to manage NEs in a network, the embedded control channel (ECC) transmits operation, administration and maintenance (OAM) information by using the D bytes.
HWECC Application
The ECC that Huawei implements provides a more flexible networking mode. The NEs can be connected through an optical port or the Ethernet port for ECC communication. In some special conditions, the Huawei equipment can transparently transmit the OAM information from the third-party equipment.
Basic Concepts of IP over DCC
This topic describes the basic concept of IP over DCC.
Features and Functions of IP over DCC
IP over DCC has the functions and features that are different from the traditional DCC.
Application of IP over DCC
In the IP DCN solution, NEs use unified DCCs to transmit TCP/IP protocol data, which enables the U2000 Web LCT to manage the NEs.The IP DCN solution is applicable to a network consisting of only OptiX transmission equipment or a network consisting of OptiX transmission equipment and the third-party equipment that supports the IP DCN function. This solution is also applicable when the equipment located in the center of a network needs to provide IP-based network management message transmission paths for the equipment at the edge of the network.
Basic Concepts of OSI over DCC
This section introduces the basic concept of OSI over DCC.
Features and Functions of OSI over DCC
When a transmission network consists of equipment from multiple vendors, the OSI over DCC transparently transmits the management information at the network layer, thereby offering greater flexibility in networking. A user can use the existing DCC resources to uniformly manage the equipment from multiple vendors without creating extra DCN channels.
Application of OSI over DCC
According to different network situations, OSI over DCC has two major applications.

Parent topic: DCN Management