VDSL CPE Mixed Results

Hey All,

We have been deploying Adtran 838(shdsl) and 868(dsl) units in our metro
area with mixed results. The devices themselves are reliable and secure
it would seem, but the speeds were are able to get are not. ie. we have
deployed 'vdsl' and needed 3 lines to get up to 10x10 speeds. We are
using an Adtran TA5000 on the other end to terminate our connections.
The distance between the site and CO is not great (under 6k feet). What
gives? Are we provisioning wrong, using the wrong equipment, or a
combination of both?
If we were able to get the speeds others have been reporting from VDSL,
life would be great.
Anyone feel free to contact me off-list or on, this has had me
scratching my head for a while now.


We've used a few Zhone ETHX-344x4 (http://www.zhone.com/products/ETHX-3400/) and been happy with the reliability. Configuration was a bugger, but if you get one of those I can share my template.


I'm going to guess you're a CLEC from your website and a common problem
I've seen in that scenario is that vectoring doesn't work between DSLAMs
because it needs all pairs to be part of the vector group so that the DSLAM
can mitigate FEXT. DSLAM vendors have been working on system level, rather
than DSLAM/binder level, vectoring for a while but cross vendor support is
questionable at best.

Read the section on system level vectoring especially:

If you are sharing binders with the ILEC and potentially other CLECs then
you really need to talk to you ILEC rep and find out what they're doing for
system level vectoring to see if there is an option for your DSLAMs to be
included. That benefits everyone and will _greatly_ increase performance.
VDSL2 speeds will otherwise be unreachable unless the ILEC gives each CLEC
their own binder, not very practical.

Scott Helms
Vice President of Technology
(678) 507-5000

I was going to ask if you've tested the cable pair at all. If the pair is
bad, or even a little out of balance, bad scotch loks, etc. VDSL isn't
going to work properly.

We have customers that are definitely in-range for VDSL but who cannot get
it because there is a 26 gauge insert between two cross-connect cabinets in
the field

Also, what do your stats look like? 6kft is getting beyond the sweet spot for VDSL2, particularly if you're trying to push 10Mbps on the upstream.

So with this 3 line connection, what speeds up and down are you getting?
You say 10X10 which I find odd for a 3 line bonded VDSL2 connection. Most
always your downstream will be much higher than your upstream on a 868