8 DCN
This chapter describes prominent Data Communication Network (DCN) features supported in TJ1600 Product family.
8.1 DCN Features
8.1.1 GCC
A DCN is General communication channel (GCC) on the node. The NEs can be provisioned to act as an OSPF router for GCC in remote management. It can exchange and maintain the routing information on GCC to which it is connected using the NMS port. The network element processes the router information on the NMS port, if the OSPF Ethernet parameter is enabled.
Similarly, the routing information on the data communication channel is processed.
8.1.2 ECC
The Error correction code (ECC) memory is a type of computer data storage that uses an error correction code to detect and correct n-bit data corruption which occurs in memory.
8.1.3 OSC
The Open Sound Control (OSC) is a protocol for networking sound synthesizers, computers, and other multimedia devices for purposes such as musical performance or show control.
This is an interface provided to manage external devices co-located with the node using the same IP network. The number of external management interfaces is 3 in TJ1600-11 and 1 in TJ1600-6. This feature is not supported in TJ1600-2.
8.3 OSPF area
The Open Shortest Path First (OSPF) is an interior gateway routing protocol based on the shortest path first or link-state algorithm.
It uses a Link State Routing (LSR) algorithm and falls into the group of interior routing protocols, operating within a single Autonomous System (AS). Routers use link-state algorithms to send routing information to all nodes in an internetwork by calculating the shortest path to each node based on a topography of the Internet constructed by each node.
Each router sends that portion of the routing table (keeps track of routes to particular network destinations) that describes the state of its own links, and the complete routing structure (topography). The advantage of shortest path first algorithms is that it results in smaller and more frequent updates everywhere. The converge is quick, thus preventing problems such as routing loops and count-to-infinity (when routers continuously increment the hop count to a particular network) thus resulting in a stable network.
OSPF networks can be divided into sub-sections called areas. An area is a group of OSPF networks, routers, and links that have the same area identification. It helps in reducing the size of the router database because the router has network topology information only possess information about network topology of only with in that area. The default area parameter is 0.0.0.1. Any valid IP address is an acceptable area parameter. TJ1600 supports single OSPF area.
8.3.2 Multi OSPF
TJ1600 supports multi OSPF area also. The multi area OSPF refers to the division of a large OSPF area into smaller areas. In bigger network deployments, the multi area OSPF helps decrease processing and memory overhead. A hierarchical network design is required for multi area OSPF.
8.4 VLAN management
The node uses OSPF protocol for the network discovery. Every node acts as a router for the DCN. After the VLAN management is enabled, each and every node establishes a one to many connections with its neighboring nodes. On each link, the node forms OSPF P2P (point to point) network on that link. This type of setup ensures that the OSPF packet generated from one node with the management VLAN will terminate at its neighboring node and does not travel over to other nodes thus preventing the formation of L2 loop.
The VLAN management has to be configured on the network side interfaces, and the VLAN should be associated with the interface.
NOTE: This feature is supported only in CEF-5 card.
8.5 Proxy ARP
The proxy ARP allows the gateway node to respond to Address Resolution Protocol (ARP) requests for subtending nodes that are within the same subnet as the customer DCN address range. The proxy ARP feature removes the need for customers to provision static routes on their routers and routing protocols (OSPF) between the gateway network elements and the customer DCN.
The proxy ARP is only supported on the LAN interface of the node. At the gateway node, the IP address of neighboring nodes is provisioned for proxy ARP.
TJ1600-I supports both automatic and manual proxy ARP modes.