Internal Ports And External Ports; Auto-Negotiation; Figure 4-11 External Ports And Internal Ports On Ethernet Boards - Huawei OptiX OSN 550 Configuration Manual

OptiX OSN 550 Multi-Service CPE Optical Transmission
System
Configuration Guide

4.2.2 Internal Ports and External Ports

External ports on Ethernet boards are used to access the services on the user side. Internal ports
on Ethernet boards are used to encapsulate and map the services to the transmission network for
transparent transmission.
External ports on Ethernet boards (that is, external physical ports) are also referred to as client-
side ports or user-side ports, which are used to access the Ethernet services on the user side.
Internal ports on Ethernet boards (that is, internal VCTRUNKs) are also referred to as system-
side ports or backplane-side ports in certain cases, which are used to encapsulate and map the
services to the SDH side.
VCTRUNKs are VC-based transmission paths, which can be implemented by using the adjacent
concatenation or virtual concatenation technology. On the U2000 window, paths are bound to
specify the bandwidth of different granularities for a VCTRUNK port.

Figure 4-11 External ports and internal ports on Ethernet boards

External port

4.2.3 Auto-Negotiation

The auto-negotiation function allows the network equipment to send information of its supported
working mode to the opposite end on the network and to receive the corresponding information
that the opposite end may transfer.
The working modes of the interconnected ports on the equipment at both ends must be the same.
Otherwise, the services are affected.
If the working mode of the port on the opposite equipment is full duplex and if the working
mode of the port on the local equipment is auto-negotiation, the local equipment works in the
half-duplex mode. That is, the working modes of the interconnected ports at both ends are
different, and thus packets may be lost. Hence, when the working mode of the port on the opposite
equipment is full duplex, you need to set working mode of the port on the local equipment to
full duplex.
NOTE
The auto-negotiation function uses fast link pulses (FLPs) and normal link pulses (NLPs) to
transfer information of the working mode so that no packet or upper layer protocol overhead
needs to be added.
Issue 02 (2011-06-30)
VCTRUNK port
Service
Interface
processing
module
module
Ethernet board
When the interconnected ports at both sides work in the auto-negotiation mode, the equipment at both sides
can negotiate the flow control through the auto-negotiation function.
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Backplane
Interface
Encapsulation/
conversion
Mapping
module
module
4 Configuring Ethernet Services
Cross-
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Cross-
connect unit
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