Comtech EF Data CDM-750 - Manual (Page 178)

CDM-750 Advanced High-Speed Trunking Modem Revision 2
Ethernet-based Remote Product Management MN-CDM750
6–34
When the presence of the optional K4 GZip Compression is detected, the ‘RxGraph’ pages provide
a live graphical representation of the trending characteristics that are available while using this
feature.
Click the appropriate time interval page tab – RxMinutes, RxHours, or RxDays – to view the
pertinent performance graph sets. Figure 6‐19 shows, for the purpose of example, the nested
RxHours page.
The time interval afforded each nested page is self‐explanatory. When the top‐level RxGraph
menu tab is selected, the page view defaults to the RxMinutes page. Click the desired tab to view
any other nested graphing page to continue.
Once any graph page is selected, allow some time for the performance statistics to
be compiled, then graphed. If the browser window is resized, allow approximately
5 to 10 seconds for the graph set to regenerate, then re‐center in the browser
window.
On each page, a set of four graphs is provided. The function of each graph on each page is
identical. Note the following:
• Rx Percent Decompression (% DeComp) – This graph represents the WAN to LAN
decompression statistic as described in Sect. 5.2.2.3.6.3 Monitor: StatsÆ
CompressionÆ WanToLan. Rx Percent Decompression is calculated using the following
formula:
100 * (1-(Bytes Out/Bytes In))
• Rx WAN Capacity – (Avail/Used) – The following information is logged into the Rx WAN
Capacity graph:
o Avail means Available Capacity, or what the satellite link is capable of receiving
at any given moment. Available Capacity is calculated using the following
formula:
(Rx Symbol Rate)(Rx Spectral Efficiency)
Spectral Efficiency is a function of ModCod, Pilots On or Off, and Normal or
Short Block being used. Refer to Appendix E. 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
before decompression (if enabled), and including any overhead the far end
modem asserts due to encapsulation or overhead due to compression. The
Capacity Used is taken directly from the “Bytes from WAN” Monitor Statistics,
as averaged over the appropriately graphed time period (i.e., RxMinutes,
RxHours, or RxDays). When decompression is enabled, the capacity used may be