<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=windows-1252"><BASE
href=x-msg://17/>
<META content="MSHTML 6.00.6000.17063" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY
style="WORD-WRAP: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space"
bgColor=#ffffff>
<DIV><FONT face=Arial size=2></FONT><BR>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=JLindsay@internode.com.au
href="mailto:JLindsay@internode.com.au">John Lindsay</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=ausnog@ausnog.net
href="mailto:ausnog@ausnog.net">ausnog@ausnog.net</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, June 17, 2010 9:59
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [AusNOG] Why not Symmetric
ingress and egress?</DIV></BLOCKQUOTE>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV><BR></DIV>
<DIV>There are also some limits in the FTTH network architecture that mean
there is less total bandwidth in the back channel.</DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2><STRONG>Not necessarily, that may be true
for GPON which is what NBN is going to use, but GEPON equipment has no such
limitation. Even for GPON it can hardly be used as an excuse to
have a 25 down 5 MB up etc. Unfortunately with NBN we will be locked
into GPON. </STRONG></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT><BR></DIV>
<DIV>It is easy to prioritise the traffic from one head end to hundreds of end
users. It is much harder to control those end points when they each want
to transmit over one shared path. </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><STRONG><FONT face=Arial size=2>Not all vendors would be affected by
this, as I understand it prioritorisation is done in the management
system profiles and once setup can be duplicated across multiple head
ends, between head ends is a matter of having sufficient switching / routing
and backhaul. Most backhaul is synchronous, so I am not sure why that
should be an issue. </FONT></STRONG></DIV>
<DIV><STRONG><FONT face=Arial size=2></FONT></STRONG> </DIV>
<DIV><STRONG><FONT face=Arial size=2>For mine it comes down to protecting the
business customer revenue as much as
anything. </FONT></STRONG></DIV>
<DIV><STRONG><FONT face=Arial size=2></FONT></STRONG> </DIV>
<DIV><STRONG><FONT face=Arial size=2>Some of the issues has come down to
the choice of equipment vendors. As always in choosing a
vendor big is not always better. </FONT></STRONG></DIV>
<DIV><STRONG><FONT face=Arial size=2></FONT></STRONG> </DIV>
<DIV><STRONG><FONT face=Arial size=2>Much of the equipment deployed
(presently) in Australia is not the same vendor as NBNs choice. Other
than Telstra, most deploy Wave7 / Enablence kit in either GPON or
GEPON or both varieties. Then there is some hills equipment.
Personally I don't see why a GPON solution was chosen over a GEPON
solution other than that the GPON vendor was familiar to the powers to be
at NBN. In fact I think it was a dumb choice, but that is
just my 2 bobs worth. This is all really back to the future
stuff. I wonder how long it will take to hear the cries from the public
re lack of competition and choice re NBN, in the same way as happened in the
1970s. </FONT></STRONG></DIV>
<DIV><STRONG><FONT face=Arial size=2></FONT></STRONG> </DIV>
<DIV><STRONG><FONT face=Arial size=2>It strikes me that there are too many so
called experts that have never done any FTTH deployments that simply do not
understand the issues. Fibre is sexy so we should do it stuff, when
fibre should be driven by a business case. </FONT></STRONG></DIV>
<DIV><STRONG><FONT face=Arial size=2></FONT></STRONG> </DIV>
<DIV><STRONG><FONT face=Arial size=2>I really do pity the 55% of homes that
are going to get aerial FTTH, talk about recipe for disaster. It isn't
the same as copper, you can't just scotch lock a bit into it when it gets
brought down by wind, fires trucks etc. For those that want to
remind me about backhoe fade, yes that happens in one spot. In the
case of fire and wind it will happen in many spots, over large geographic
areas. Trying to reconstruct quickly will take time. You cant run
fibre acress a driveway to effect quick repairs like copper. I could go
on but I am already off topic.</FONT><BR></DIV></STRONG>
<DIV>regards Tim</DIV></BLOCKQUOTE></BODY></HTML>