Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.
Comment: Migrated to Confluence 5.3

Here are some handy tools on the web. They do a variety of things related to HiSeasNet operations. Feel free to comment on or suggest more of these!

Satellite Geometry Tools

SatBeams is an excellent Google maps tool for locating satellites, displaying their footprints, and checking azimuth, elevation, and power level readings. They have a new version coming out that is available at until it becomes their main page. It still has a few quirks at the moment.

Jim Akens also suggested looking at this geosync satellite list and maybe even playing with their web-controlled SpecAn.

This tool figures out a azimuth and elevation for a given geostationary satellite and a given position.

Robbie Laird wrote this simple script that pulls the ships position from a udp broadcast and prints out the AZ/EL of a satellite.

Solar outages and some other satellite-related calculations can be fairly easily calculated using the tools locate at Solar outages in particular are at

Modulation Coding calculator

Newtec released a new ModCod calculator tool in Excel. Check out the users guide for details.

There is also a calculator that helps with some basic bandwidth efficiency features.

City Lat/Lon tool

This tool is a lookup table for the latitude and longitude of major cities in the US. Comes in handy sometimes.

Subnet calculators

The math may seem to get a little funny when calculating IP subnet masks, network addresses, and broadcast addresses. It is all straight forward based on powers of two, but is a pain to derive all the time. These tools provide a little assistance getting the numbers right and converting between all of the formats used to indicate the addresses and masks.


MTU issues in general and specific to GRE tunneling

L-band conversion table

This is a quick lookup table of some L-band conversions to C-band and Ku-band frequencies. Not particularly accurate, but a good sanity checker to make sure things are in the right ballpark. Better to do the conversion by hand correctly based on the local oscillator of your gear.

Bandwidth testing

For detailed bandwidth tests that allow adjusting different window sizes and such, try iperf. It helps to use a window size of 16K for our satellite links

Cisco routers have an undocumented (or at least minimally documented) bandwidth test tool in their routers called ttcp. It appears to be some flavor of iperf responder built into their IOS. Routers can be setup as senders or receivers. As a result, it allows for links to be tested just between routers or between routers and hosts running the ttcp software. More info from Cisco is at Again, use 16K windows for best results...and be careful of the number of packets you send as the default is a very large number!

For quick web-based speed tests, try or These tests may not be the most accurate for our long-latency, low-bandwidth, high-jitter, often high-saturation links as the tests are designed for broadband computers. You may find a properly set window size on the running computer may improve the performance. See Wikipedia for more discussion and links regarding Long, Fat Network links. There is also a discussion of TCP tuning. The links at the bottom have pointers to TCP stack test/tweak tools that may prove worthwhile.


The concept of all of the tools above is to flood the network and see how much data got through. This will actually reduce the usable bandwidth to nothing while the test is running. As a result, it will report back the available bandwidth when the test was run. If you sustain x kbps, and your speed test returns y kbps, your actual bandwidth of the link is x+y kbps.
There are other tools that attempt to measure actual bandwidth on a link, but I have not tried them. They generally function by watching special TCP packets flow across the link and determining when they would saturate based on their timing. If you are up for it, feel free to try out BW-meter tools and let me know what your experience is.

Per-User Bandwidth Monitoring and Traffic Control


This was a tool that was mentioned during RVTEC '09. It lets individual users see what their usage is. This can help them understand how much bandwidth they consume. "Oh! YouTube really does use a lot of bandwidth! Maybe I shouldn't use it so much..."

USAP uses Antamedia Hotspot Software to manage a quote-based hotspot in their ship's internet cafe. They also use some content filtering based on the redirection scheme. This helps block software updates, too.

Misc Cisco Tools

There are a variety of Cisco tools listed at a Cisco-centric open source site.

Earth station EbNo values

Earth station EbNos for each ship can be fetched at and should be a pretty small/quick load (suitable for cell phone browsers). The page is updated on the fly directly from the modems. Note that an EbNo of "0" means an modem is unlocked, while a measurement of "19.5" indicates an EbNo of 19.5 dB or higher (probably too much).

Network Monitoring Tools

There are a variety of tools for monitoring different aspects of networks these days. Some are based on SNMP and require devices to look at SNMP data. Others use netflow to track summaries of flows heading to or from routing or switching devices. Others are just tools for keeping track of pings. Here is a very incomplete list of some tools that have been used on shore or ships in the past. There are likely other tools that fit a particular need closely. 


HDD Accurate Network Monitor:


Cricket graphs:


PingList: A windows-based tool for pinging down a chain of IP addresses. It shows where the ping stops. It may be useful to set this up with some addresses on and off the ship to see where things break when there is connectivity trouble.

Ship tracking tools

There are a number of websites that suck up ship positions and display them: