Ethernet Service Bandwidths Carried By Vctrunks Of Ethernet Boards - Huawei OptiX OSN 550 Configuration Manual

OptiX OSN 550 Multi-Service CPE Optical Transmission
System
Configuration Guide
6.3 Ethernet Service Bandwidths Carried by VCTRUNKs of
Ethernet Boards
To determine the level of the bandwidths to be bound with a VCTRUNK and the number of
paths that are required for an Ethernet service, you need to calculate the theoretical bandwidth
of the Ethernet service that can be carried by a VCTRUNK.
Bandwidth = Number of paths bound with the VCTRUNK x Payload rate of the binding
granularity x Encapsulation efficiency of the encapsulation protocol
The payload rate of the VC-12 is 2.176 Mbit/s; the payload rate of the VC-3 is 48.384 Mbit/s;
the payload rate of the VC-3 is 149.760 Mbit/s.
GFP encapsulation efficiency has different values in the following two scenarios:
l
l
NOTE
In actual situations, you can estimate the level and quantity of the paths according to the
following principle: One VC-12 path carries 2 Mbit/s services; one VC-3 path carries 48 Mbit/
s services; one VC-4 path carries 150 Mbit/s services. For example, in the case of a 10 Mbit/s
Ethernet service, the VCTRUNKs can be bound with five VC-12 paths.
Issue 02 (2011-06-30)
GFP encapsulation efficiency = Ethernet frame length/(Ethernet frame length + 12-byte
overhead), when the GFP protocol uses FCS32 as the check field.
GFP encapsulation efficiency = Ethernet frame length/(Ethernet frame length + 8-byte
overhead), when the GFP protocol does not add the check field.
When the Ethernet board uses the GFP protocol to encapsulate Ethernet services, you can determine
whether a check field is used during the encapsulation by setting the Check Field Length parameter. By
default, FCS32 is used as the check field. In this case, if the Ethernet board uses the default GFP parameter
settings, the theoretical bandwidth of the VCTRUNK bound with five VC-12 paths is 10.938 Mbit/s when
the Ethernet frame length is 1500 bytes and the theoretical bandwidth of the VCTRUNK bound with five
VC-12 paths is 12.025 bit/s when the Ethernet frame length is 64 bytes.
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