LinuxSA Mailing list archives

  From: Mark Newton <newton@atdot.dotat.org>
  To  : John Edwards <isplist@pinnacle.net.au>
  Date: Thu, 17 Feb 2000 13:01:00 +1030

Re: Broadband Internet rocks

On Thu, Feb 17, 2000 at 11:26:41AM +1030, John Edwards wrote:

 > Mark Newton wrote:
 > 
 > > ... just sitting back enjoying the new 10 Mbps net link I finished
 > > installing at home last night.   I know nobody on LinuxSA really
 > > gives a damn, but it's probably a forum with less people who will
 > > go "Huh?!" than most others, and hey, I've gotta tell someone! :-)
 > 
 > This is a forum with more people who want to know how it was achieved,
 > how much does it cost, and is there any point to you having a 10mb link
 > for sites outside of Internode :)
 
Fairy nuff then.  Here's a long-ish message which describes what it
is, compares it to other equivalent ways of connecting locations, 
provides indicative pricing, and and describes some of the technology
behind the network.  Some of it's commercial in nature, so skip it
now if you're not interested in that kind of thing.  If you work for
a company which has a requirement for multi-megabit data carriage
services, read on.

The link is implemented as an Agile Carrier Data service.  For those
who have never heard of Agile Communications before, it's a 18-month-old
company owned by Internode;  it happens to own a telecommunications
carrier license, so think of it as one of the world's smallest phone
companies :-)  http://www.agile.com.au/

Agile provides point-to-point or point-to-multipoint carrier services --
Think along the lines of a Telstra Megalink, Frame Relay, DDS Fastway,
etc style service and you'll know the kind of things Agile competes
with in the marketplace.  One of the main differences between Agile
Data Services and the link technologies listed above, though, is that
Agile services speak ethernet protocols.

Let's look at what that means:  Let's say you're at a company which
wants a 64k link between a pair of offices.  You go to Telstra and
say, "Hey!  I want ISDN!" and they provide you with ISDN.  You can't
use that ISDN link until you run out and buy an ISDN router, which
will cost between $1500 and $3000.  As your business grows you might
increase the bandwidth to 128k, which is fairly simple with the same
router, but if you want to go past 128k you have to buy more equipment:
A router with more interfaces, perhaps an ISDN external TA, etc -- Another
few thousand dollars in equipment costs. 

Let's say you get to 256k and want more bandwidth again.  Multilink
ISDN doesn't make a whole lot of sense at speeds higher than 256k 
due to link costs and protocol overhead, so you "upgrade" your 2 x Onramp2
services to a DDS Fastway service -- But the "upgrade" means Telstra
will rip all your ISDN infrastructure out and replace it with totally
different network termination equipment, so you'll need to buy *ANOTHER*
router with different interface types again, spending more money, before
you can use the service.  

If you want to link more offices as the company grows more, you might
decide that Frame Relay makes more sense -- So you get yet another type
of line termination equipment, and the frame relay card you put into your
Cisco will cost about $18,000, and you'll probably need to buy another
chassis to plug it in to anyway.  Yecch.

Agile Carrier services are different.  Regardless of the bandwidth you
order, they use ethernet protocols.  You pay a once-off setup fee;  in
future, you can alter the amount of bandwidth you have by making a 
phone call and paying a different monthly fee.  The only equipment you
need to connect to the service is a hub or a switch at each location;
Simply take a patchlead from the uplink port on a hub at point A and
plug into into your Agile RJ45 socket, and do the same with your hub
at point B, and suddenly points A and B appear for all intents and purposes
to be part of the same ethernet (e.g.: a traceroute from a host at point
A to a host at point B will show zero hops, just like it would if the
two hosts were in the same building on the same ethernet).

If you want to add a "point C" later, you pay a smaller setup fee
to add an additional "end" to your Agile Data Service;  Plug your hub
or switch into the Agile RJ45 socket at point C and suddenly *that*
LAN is part of the same network as locations A and B too.

There are different setup fees for 256k to 2Mbps, 2Mbps to 10Mbps, and
10Mbps to 100Mbps.  If you cross one of those boundaries, you pay the
difference between the setup fee you've already payed and the next
increment, rather than paying an entire setup fee for a complete new
service like Telstra would make you do.

If you happen to want to carry Internet bandwidth over your Agile link,
the answer to that is simple:  You end up with a point to point link
where one point is your office and the other point is your ISP, and 
your ISP actually provides you with a permanent link on Ethernet.
You're not locked-in to using Internode as your ISP, so if you like the
service you're getting from someone else there's no problem with that
whatsoever.  Agile currently provides several ISPs with links to SAIX,
for example.

That's enough about what it is.  How is it implemented?  The answer is
with VLANs.

Most VLAN-capable ethernet switches support the idea of trunking;  that's
how you cascade switches together.  If you have a pair of switches trunked
together, you can create a VLAN, then assign a port in the first switch
and a port in the second switch to that VLAN.  If you plug hubs or 
other switches into those two ports, the "LANs" on each port can talk
to each other because frames which need to cross the boundary are trunked
by the switches.

The next logical step:  What happens if the trunk happens to be a long-
distance link?  Then you can inject ethernet frames into the first
switchport, they'll be trunked over your long-haul backbone, then 
they'll be emitted by the second switchport. 

Agile uses variations on that idea.  The Agile carrier network is a 
distributed VLAN trunk.  It uses a combination of 802.1q, ISL and
customized Agile VLAN tagging to pass frames around a cloud of
VLAN-capable devices connected on Microwave, copper, fibre-optic
cable around the CBD, Infra-red, Laser, tin-cans-and-string, and
anything else which makes technological or economic sense.  At the
end of the day, Agile customers don't need to care about *how* Agile
gets into their buildings, any more than Telstra customers need to
care about whether their ISDN services are provided on fibre or copper.

Most Agile customers have a VLAN-decoding black-box called a "Trio",
provided by Agile to implement the service, either in an equipment
rack, bolted to the wall, in the ceiling, whatever.  Customer ports
from the Trio are presented as RJ45 ethernet sockets at a location
determined by the customer.

The setup fees for an Agile service at a new location start at $4000 per
end, which includes installation, in-building cabling, the equipment
needed to run the service, any antennae which are needed, etc -- Basically
everything on Agile's side of the customer port.  No further setup fee
is necessary for any bandwidth increases up to at least 2 Mbps (10 Mbps
in some locations).  Additional "ends" can be added to an existing
service for $500.  The monthly fee depends on the bandwidth utilized;
$400 per month for 256k, $1250 per month for 2 Mbps, many points in
between, many points higher (service offerings currently go up to 100
Mbps).  The prices compare very favorably to competing service offerings
-- The ongoing costs on a 2 Mbps service are roughly one third of the
costs from the equivalent service from Telstra, and the size of the
setup fee is offset by the fact that you don't actually need to buy
any equipment to plug-in to it.  For more pricing information, call
Andrew Kempster at Agile on 8232-1234. 

The network is growing, and Agile can't currently provide service in
all areas, but certainly any sites in the CBD or within a radius of
about 10km of the city are easy to do at the moment via fibre, copper
and spread-spectrum (subject to a site-survey), some existing 
customers are up to 20km away from the CBD, and Agile is currently
deploying a broadband voice and data network into the Coorong, which
will bring parts of the Adelaide Hills and many regional areas south
of Adelaide into the network as well before the end of this year.

I'm currently writing the software for the second-generation Trio,
which is why I've ended up with a 10 Mbps link at home (don't try to
call me at work next week, ok? Gotta test the code somewhere, right? :-)
The Trio software is a FreeBSD kernel with Agile-authored VLAN code.
My link is implemented via an 11 Mbps spread-spectrum Microwave link
to Agile's facility on the roof of Santos House, which is trunked back
to Internode on a point-to-point microwave link, where the B-end of
my service is a switchport in one of the equipment racks in the
Internode computer room.  The spread-spectrum gear we're using is
provided by Aironet, http://www.aironet.com;  the radio I'm using
at the moment is a PCI4500 (11 Mbps 802.11 frequency-hopping 
spread-spectrum interface on a PCI card), driven by the "an" 
device driver in the FreeBSD kernel, with Agile's custom VLAN switching
code doing the customer port decoding/encoding and VLAN tagging.

 > (Who's planned 2 meg link to home is now looking inadequate)

:-)

    - mark

--------------------------------------------------------------------
I tried an internal modem,                    newton@atdot.dotat.org
     but it hurt when I walked.                          Mark Newton
----- Voice: +61-4-1620-2223 ------------- Fax: +61-8-82231777 -----

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