Month: February 2008

30Mbps to Tye’s house

Our team today turned up pair bonded ADSL2+ to Tye C’s place. Tye works in tech support, and happens to live a little over one mile of copper wire away from the Santa Rosa downtown central office. And tonight, Tye is rocking 30Mbps of downstream bandwidth on two simple copper pairs. Nice work guys!

The loops to the house are each running about 15Mbps sync. The maximum sync that ADSL2+ can deliver is 24Mbps. But like ADSL1, which can do 8Mbps, in the real world we expect a slightly lower level. In ADSL1, the maximum practical speed is generally 6Mbps for most locations, and for ADSL2+, I think we’ll be real happy if we see 20Mbps as the top end in the real world. The 15Mbps speed that Tye’s got is likely to be more common.

This makes bonding even more interesting. Every home has at least two “phone lines” – we can deliver voice lines on both of them (main home line, second line for home office or FAX perhaps), plus bonded IP at 2x the ADSL2+ sync. That means some serious bandwidth potential for our business and residential users.

I’ll caution that we haven’t yet designed product specifications and price points for residential users at this speed, but the technology does work. The business model is a separate question.

Next generation broadband technical resources

For folks interested in some of the technical details of the new solutions we are deploying, here are some links:




Our current deployment can support bonding of up to two pairs of ADSL2+, and up to eight pairs using EFM. You can do the math. =)

First e.SHDSL test loop

At over a mile of distance, we’re very pleased with the 3.5Mbps symmetric performance we’re seeing on this single pair test loop. With eight pair bonding (8×3.5, in this example), this means delivery of a 25Mbps symmetric link is possible at this sort of range. This very exciting technology uses “Ethernet in the First Mile” (EFM) technology to deliver speeds from 1.5Mbps (T1) to 45Mbps (T3) on one to eight copper wire pairs.

e.SHDSL 3.5Mbps symmetric loop

Symmetric products at T1 to T3 speeds are ideal for business customers seeking to extend their local area networks at Ethernet speeds, and for fast Internet performance both downstream and up.

ADSL2+ running 16Mbps

This loop is a bit over one mile long (~5500ft). Downstream sync is 16Mbps, upstream sync at 1.1Mbps. This is served out of the Santa Rosa 01 (downtown) central office, from our new DSLAM deployment there.

ADSL2+ Speed Test

Click for larger, more legible image.