How many NEs at a site can be interconnected through the automatic extended ECC

The HW ECC solution establishes
ECC routes using the shortest path first algorithm. "Shortest path" means
that the path contains the least number of NEs compared with other paths. It
does not mean that the physical reach is the shortest. The following describes
how an NE establishes an ECC route:
a. The physical
layer of the NE maintains the status information for the DCC channel
corresponding to a line port.

b. The MAC layer of
the NE establishes the MAC connections leading to the adjacent NEs.

− The NE
periodically broadcasts the connection request frame (MAC_REQ) to the adjacent
NEs.

− When receiving
the MAC_REQ frame, the adjacent NEs send back a response frame (MAC_RSP).

− The NE
establishes the MAC connection between itself and either adjacent NE when
receiving the MAC_RSP frame within the specified time.

c. The network layer
of the NE creates its network-layer routing table.

− The NE creates an
initial network-layer routing table based on the established MAC connections.

− The NE
periodically broadcasts its routing table to the adjacent NEs through the
routing response message.

− When receiving
the routing response message, the adjacent NEs update their own network-layer
routing tables based on the shortest path policy.

At the
next routing broadcast time point, the NE broadcasts the current network-layer
routing table.




ECC Network
Division Principle

ECC Network Division Solution:

a. The suggested scale of an ECC subnet is within 50 NEs and
the maximum scale is 100 NEs. b. If the NEs on an ECC network exceed 50, it is suggested
that gateways be added to divide the network into multiple subnets.

c. DCC channels are prohibited
between ECC subnets.

d. When an ECC network is divided, an
external DCN must be planned.

e. The ECC route protection function cannot be affected in
the ECC network division.

Principle for the Extended ECC Plan:

a. The NE supporting the extended ECC
feature is used and IP addresses must be in the same network segment.

b. A loop is not allowed when an extended ECC network is formed using hubs
and serial ports of NEs.

c. When a hub is used in the extended ECC networking, it cannot
be connected to other devices.

d. The NEs (including servers and
clients) on an extended ECC network cannot exceed eight; otherwise, the NEs
will be reset. If the scale is no more than four, the ECC can be extended
automatically. If the scale is more than four, the ECC must be extended manually.

e. Extending ECC manually is recommended, because the manual
mode can reduce negotiations between NEs, and fewer resources are occupied.

f. When connected to the NMS using a hub, the gateway NE cannot
automatically extend the ECC.

g. When the ECC is extended manually, the NE near to the NMS
is recommended as the server for TCP connections and other NEs as clients. The
port number ranges from 1601 to 1699.

https://forum.huawei.com/enterprise/en/ecc-network-division-principle/thread/472967-875

Hello, friend!

The extended ECC communication is established through the Ethernet. The number of automatically extended ECCs must be equal to or less than four. The number of clients connected to a server of the manually extended ECC must be equal to or less than seven. The clients, however, can continue to be connected to the server. The hubs/switches can be cascaded. This is only related to the limitation of the entire network scale. This basic principle applies to each product and is related to the platform.

In the metro WDM system, the ETHERNET1 and ETHERNET2 cascading communication modes are not supported by the long-haul WDM system. The second network port of the long-haul WDM system is not used for ECC communication. In addition, it is recommended that the number of cascading levels of network ports on a Metro WDM network not exceed 8.

Thanks!