What do you get when you cross a small business owner with a very high speed DSL line?

Unexpectedly, I find myself on VDSL2 via Snap Internet and Telecom Wholesale. How fast is it? I tested using Speedtest.net against Snap’s server in Christchurch, with 69Mbit/s download and 9.2Mbit/s upload speeds recorded - not to mention a 27ms ping time.

Speedtest doesn’t tell the whole network story but overall I’m very pleased with VDSL2. Overseas speeds vary, but well-connected servers dish it out at 30-40Mbps down.

VDSL2 is a symmetric service so why am I only getting 10Mbps up? That, unfortunately, is how Telecom decided to set up VDSL2. I haven’t had a clear answer as to why, or the reason Telecom uses interleaving on short VDSL2 loop lengths - you have to be less than 700 metres away from the DSLAM.

VDSL2 is designed to provide 100Mbps up and down and latency to Snap should be in the 10 to 15ms range without interleaving on.

Still, I love the ten-fold jump in upstream speed which for me means a big productivity increase.
Getting VDSL2 was a very long process. Going through my emails I see that PC World asked me to cover VDSL2 from Vodafone in May 2008 and again via Telecom Wholesale in April the year after. It didn’t happen with either party.

Things went back and forth but last year a roadside cabinet was placed roughly 500 metres away and everything looked good to go for a trial in October. Again however the trial was postponed and I learnt this year that the cabinet didn’t have the right software installed for VDSL2. By this time I had given up.

However, the cabinet was upgraded at the end of March 2011. Snap was finally able to put through an order for VDSL2 but there were still some hurdles to cross.

First, the wiring in my house. Chorus offered last year to install a Service Delivery Point or SDP to bypass older wiring, making sure the DSL signal doesn’t share the line with telephones and jack points.

As it happened, the VDSL2 service went live before the SDP arrived which was a useful experience by itself. Dave the Chorus installer kindly lent me his modem to try out the service but neither of us had a BT/RJ-11 cable and as a temporary measure I connected the modem to an ADSL2+ splitter.

This works but shaves off a good amount of speed. Once I found a BT cable and removed the splitter the attainable downstream bandwidth jumped from 36.5Mbps to 49Mbps.

A week later, Darren from Chorus/Visionstream and installed the SDP with CAT5e cable straight to the jack. It was much harder than it looked - Darren had to crawl under the house for hours.

While Darren battled spiders under the floors I had a look at the opened up SDP. It’s a fairly simple device with an xDSL splitter and wiring block inside connecting four different jacks. One is for DSL, another for analogue phones and two for VoIP service through ATAs.

The SDP made a noticeable difference: downstream rates improved by 1.5-1.6Mbps and upstream by around 1.8Mbps. Other connection parameters such as attenuation and line noise were reduced which really helps with VDSL2.

I wasn’t happy with the borrowed Alcatel-Lucent Cellpipe 7130 VDSL2 router however. This has a huge amount of features but is difficult to configure and locks up regularly; steer clear of the Cellpipe.

Telecom Wholesale sent a Thomson TG789vn modem which is less feature-rich but nicely designed and has worked fine so far. Unfortunately, there is a limited choice of VDSL2 modems, especially ones with CPU horsepower to run gigabit Ethernet switches for LANs which is really what you want.

A final snag was that my downstream appeared to be limited to 50Mbps. At the short distance to the cabinet the connection should reach close to 100Mbps.

It turned out that my port in the cabinet was configured to VDSL2 Profile 8d, with 8.832MHz bandwidth and 2,048 4.3125kHz carriers and +14.5dBm power.

Once Snap had the port reconfigured to the more approrpritate Profile 17a, with 17.664MHz bandwidth and 4,096 carriers, my connection was rocking along at 77Mbps line rates. In fact, the attainable line rate is just under 90Mbps, but I’ve never got that high.

There is also a Profile 30a with 30MHz bandwidth and 3,479 8.625 kHz carriers that provides 200Mbps maximum speeds but I gather the Alcatel-Lucent DSLAMs in the cabinets only support Profile 17a.

VDSL2 took three years to arrive and I’m not sure how much it’ll cost me yet. One thing’s for sure though: I’ll need a much larger data cap than the 60GB I had for ADSL2+ at VDSL2 speeds. 200GB a month sounds about right.

With UFB fibre so far away VDSL2 is a good bet for many small businesses and it’s a shame the service wasn’t deployed sooner. Looking at the above, I can see why it was delayed but fingers crossed it will be affordable when generally available -- and without artificial upstream limits and interleaving turned on.

Juha Saarinen