User's Manual Part 1

Chapter 3: System planning Link planning
Calculating data rate capacity
The data rate capacity of a PTP link is defined as the maximum end-to-end Ethernet throughput
(including Ethernet headers) that it can support. It is assumed that Ethernet frames are 1500 octet.
Data rate capacity is determined by the following factors:
• Licensed data throughput capability (ODU variant: Lite, Mid or Full)
• Link Symmetry
• Link Mode Optimization (IP or TDM)
• Modulation Mode
• Channel Bandwidth
• Link Range
Calculation procedure
To calculate the data rate capacity of a PTP 650 link, proceed as follows:
1
Use the tables in
Data throughput capacity tables on page 3-49
to look up the data throughput
capacity rates (Tx, Rx and Both) for the required combination of:
•
Link Symmetry
•
Link Mode Optimization
•
Modulation Mode
•
Channel Bandwidth
The tables contain data rates for
PTP 650 Full only.
2
The tables
contain data rates for links of zero range. Use the range adjustment graphs in Data
throughput capacity tables
on page 3-49 to look up the Throughput Factor that must be
applied to adjust the data rates for the actual range of the link.
3
Multiply the data rates by the Throughput Factor to give the throughput capacity of the link.
Note
The data rates for adaptive symmetry apply to the most asymmetric case where the
link has significant offered traffic in one direction only. The data rates for adaptive
symmetry with bidirectional offered traffic are the same as those for link symmetry 1:1
with link optimization IP.
Page
3-23