Comtech EF Data CDM-760 User Manual
Page 229
Ethernet-based Remote Product Management
Revision 2
CDM-760 Advanced High-Speed Trunking Modem
MN-CDM760
7–71
When the presence of the optional K4 GZip Compression is detected, this page provides a live
graphical representation of the trending characteristics that are available while using this feature.
Once you open or refresh this graph page, allow some time for the modem to
compile and graph the performance statistics. If you resize the browser window,
allow approximately 5 to 10 seconds for the graph set to regenerate, then re-center
in the browser window.
This page provides three performance graphs and four configuration status graphs:
•
The Tx Percent Compression graph represents the LAN to WAN compression statistic as
described in Chapter 6. FRONT PANEL OPERATION Sect. 6.2.3.6.3 (Monitor: Stats)
Compression LanToWan or WantoLan.
Tx Percent Compression (% Comp) is calculated using the following formula:
100 * (1-(Bytes Out/Bytes In))
•
The Tx WAN Capacity graph logs the following information:
o
Avail means Available Capacity, or what the satellite link is capable of transmitting at
any given moment.
Available Capacity is calculated using the following formula:
(Tx Symbol Rate)(Tx Spectral Efficiency)
Spectral Efficiency is a function of ModCod, Pilots On or Off, and Normal or Short Block
being used. Refer to Appendix B. Es/No MEASUREMENT for detailed information about
and reference tables pertaining to Spectral Efficiency.
o
Used means Capacity Used, or the data rate of all traffic sent over the satellite after
compression (if enabled), and including any overhead the modem asserts due to
encapsulation or overhead due to compression. The Capacity Used is taken directly from
the “Bytes to WAN” Monitor Statistics, as averaged over the graphed time period. When
compression is enabled, the capacity used may be substantially less than the terrestrial
rate of the user traffic due to the effect of the compression card.
•
The Tx ModCod and Remote Es/No graph is particularly useful when the modem is running
is ACM mode, as it maps the remote Es/No of the far end modem synchronously along with
the near side (local) Tx ModCod used. Two pieces of data are graphed in time synchronous
manner:
o
The left side of the graph has a vertical key of Tx ModCod (blue).
o
The right side of the graph has a vertical key of Remote Es/No (red).