The MacAlba

I’ve put a photograph of the BorderNET satellite link on my photoblog to illustrate my earlier articles that were posted here.

We’ve now had BorderNET 512/128 satellite internet access at home for 10 days. The down- and up-link speeds continue to maintain advertised throughput (mostly noticeable on large file transfers). The long latency caused by the distances required to be travelled via satellite ensure that web browsing, for example, isn’t “snappyâ€? (my web request packet has to travel in the order of 70,000 km or more to get to the server; the returned data has to travel the same distance to get to me). Likewise, character-based logins to Unix systems is challenging (it takes a while for the echoed characters to get back).

I keep the satellite modem running 24 hours/day and use SNMP to record the number of bytes transferred to and from my residential network router interfaces. For reasons as yet unknown, the satellite link is reset, or the modem rebooted, daily during the early hours of the morning. This has caused problems for sessions I run at that time of day. I’ve worked around it for the time being by shifting the kick-off times of various tasks.

The satellite modem is a “Gilat SkyEdge IPâ€?. The received signal seems quite healthy - the carrier to noise level usually sits at +12.6 to +12.7 dB. It’s peaked at +13.14 dB, and dropped to +11.08 during rain. The modem is rumoured to contain a built-in proxy facility (they call it “embedded accelerationâ€?[1]) - this might explain why some non-web, port 80 communications have been difficult.

[Update April 1, 2006: the carrier to noise level dropped to +9.33 during heavy rain yesterday morning.]

The BorderNET web page which displays the volume of my downloaded data runs about 30 hours in arrears which, while not unworkable, seems to be a larger lag than is really necessary (given that I can maintain my own record of downloads in near-realtime (within 5 minutes)). [The BordetNET usage page is nearly 60 hours in arrears as I type].

I’ve called BorderNET helpline a few times but gave up waiting to speak to anybody after 10 to 15 minutes. Sadly, their help desk staffing levels seem no better than other ISPs.

All in all, though, even with the few rough edges it’s still a better service than the 45 asynchronous kilobit/sec I had via a dial-up modem.

[1] Gilat’s full name for it on their SkyStar 360e web page is “Embedded TCP/IP implementation coupled with unique Internet browsing acceleration technologies provides high performance and an enhanced user experienceâ€?. I can’t say that my user experience feels enhanced. It’s “OKâ€?, perhaps, but not “enhancedâ€?.

After a longer than expected wait, and some stuffing around, the 2-way satellite internet access service from BorderNet was installed a few days ago. In a sense the installation process was an anti-climax - it took less than an hour and a half from arrival of the installers, to the home wireless network being connected to, and operational on, the ‘net.

The service plan I chose gives us a 512 kbit/s downlink with a 128 kbit/s uplink. The price includes 5 gigabytes per month of downloaded data, with additional charges payable in excess of that limit.

I note that BorderNet now has a “traffic shapingâ€? option whereby I can opt to have the downlink data usage above the 5 GB quota “shapedâ€? down to 64 kbit/s for the remainder of the billing period. I’ll have to take note of my usage for the next 10 days or so before deciding whether to take advantage of that offer or not.

In terms of performance, so far, the service hasn’t disappointed. The down- and up-link speeds are pretty much exactly 512 and 128 kbit/s respectively. The long network latency imposed by the use of geostationary satellite is rather annoying but can’t be helped.

So, all in all, it’s been good so far.

I flew back from Sydney (which is at sea level) to Armidale (which is 1000m / 3300ft above sea level) last night. I know perfectly well that this means that there is a non-trivial pressure difference between the two altitudes.

Once again, though, without thinking anything of it, I uncapped the tube of toothpaste and, squiiiiiirt, the toothpaste tube gushes more toothpaste than any toothbrush can usefully use until the pressure is equalised.