Alcatel-Lucent 1643 AMS User's Operation Manual page 95

Management communication setup
The figure of the OSI-DCN consists of two LANs and a number of DCC channels in
an SDH transmission network with point-to-point configuration and two rings
connected to an EMS. The management system server is used as an EMS. The
management system is connected to the transmission network via Gateway Network
Elements (GNEs) by the LAN. The network elements are connected to each other by
DCC channels.
LCN
In the case where there is no DCC connectivity between nodes, a Local
Communications Network (LCN) can be used to connect the nodes to each other. See
the LCN on the right side of the figure.
DCN communication protocols
Communication protocols used in the Data Communications Network (DCN) between
the nodes include:
• Ethernet (on the 10BaseT) LAPD (on the DCC channels)
• OSI Network Protocol (DCN wide)
The OSI Network Protocol (OSI-DCN) is used for routing management data between
nodes in the DCN.
ISO-OSI network protocol
The network protocol used between nodes is the ISO-OSI Network Protocol (ISO/IEC
8648). According to this protocol a node in the network can behave as an End System
(ES) or as an Intermediate System (IS), sometimes called a router.
End systems
Nodes behaving as End Systems perform no forwarding of data packets. They
communicate with each other on an end-to-end basis via Intermediate Systems.
Intermediate systems
Intermediate Systems are used for routing data between nodes and (sub) networks. The
End System - Intermediate System (ES-IS) protocol is responsible for the exchange of
data between an End System and Intermediate System. A network element can act both
as an End System as well as an Intermediate System. However, an ITM-SC, for
example, can only act as End System.
IS - IS protocol
The Intermediate System to Intermediate System (IS-IS) protocol is used between
Intermediate Systems in the DCN. The IS-IS protocol maintains the IS Routing
Information Base (RIB). The information in this information base is used for the
routing of management data packets in the DCN by the Intermediate Systems.
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365-312-807R7.2
Issue 4, May 2007
Alcatel-Lucent - Proprietary
See notice on first page
Basic DCN principles
4-5